Sunday 5 May 2019
Thursday 2 May 2019
22, Chemical Coordination and Integration class 11
Chemical Coordination and Integration Notes Download in pdf
Chapter 22 Chemical Coordination and Integration Download in pdf
|
Chapter 22 : Chemical Coordination and Integration
Download Notes IN PDF For Class 11 Biology
POINTS TO REMEMBER
Endocrine glands : These are ductless glands which secrete hormones directly into the blood stream.
Hormones : Non-nutrient chemicals, synthesised in trace amounts, acts as intracellular messengers and are specific in their action.
Hypothalamus
�It is basal part of diencephalon.
�Has neurosecretory cells called nuclei which produce hormones to regu late the synthesis and secretion of pituitary gland hormones.
Two types of hormones released are
Releasing hormones : Stimulate secretion of pituitary hormones, e.g., Gona- dotropin releasing hormone stimulates pituitary gland to synthesise gonadotrophins.
Inhibiting hormones : Inhibit secretions of pituitary hormones, e.g., Soma- tostatin inhibits secretion of growth hormone.
Pituitary Gland :
�Located in bony cavity called as sella tursica.
�Attached to hypothalamus by a stalk.
Divided anatomically into : Adenohypophysis and Neurohypophysis.
�Hormones released from hypothalamic neurons reach anterior pituitary through portal system.
�Direct neural regulation by hypothalamus occurs in posterior pituitary.
PITUITARY GLAND
Adenohypophysis : Pars intermedia : Produces only one hormone melanocyte stimulating hormone.
Pars distalis
�Growth hormone (GH) : Oversecretion leads to gigantism and low secretion causes dwarfism.
�Prolaction (PRL) : Growth of mammary glands and formation of milk in them.
�Thyroid stimulating hormone (TSH) : Stimulates synthesis and secretion of thyroid hormones from thyroid gland.
�Adrenocorticotrophic hormone (ACTH) : Stimulates synthesis and secretion of steroid hormones called glucocorticoids from adrenal cortex.
�Luteinizing hormone (LH) : Synthesis and secretion of hormones called androgens in males, and helps in ovulation and maintenance of corpus luteum in females.
�Follicle stimulating hormone (FSH) : Regulate spermatogenesis in males, and growth and development of ovarian follicles in females.
Neurohypophysis
Pars Nervosa :
�Oxytocin helps in contraction of uterus during child birth and milk ejection from mammary gland in females.
�Vasopressin : Acts on kidney and stimulates reabsorption of water and elec- trolytes by distal tubules to reduce water loss through urine. It is also called as Anti Diuretic Hormone (ADH).
PINEAL GLAND
�Located on dorsal side of forebrain.
�Secretes melatonin to regulate 24-hour rhythm, sleep-wake cycle, menstrual cycle, pigmentation etc.
THYROID GLAND
�Has two lobes on either side of trachea interconnected by isthmus (connective tissue).
�Composed of follicles and stromal tissues.
�Follicular cells synthesise thyroxine (T 4 ) and triiodothyronine (T)
�Iodine is necessary for normal functioning in of thyroid.
�Goitre (Hypothyrodism) : Enlargement of thyroid gland. Hypothyrodism may lead to mental retardation and stunted growth (cretinism) in the baby if it occurs during pregnancy.
�Hyperthyroidism : Occurs due to cancer or due to development of nodules in thyroid glands. Effects body physiology as abnormal high levels of thyroid hormones is synthesised. 3 ).
�Also secretes a protein hormone called Thyrocalcitonin (TCT) which regulates blood calcium level.
PARATHYROID GLAND
�Present on back side of thyroid gland. Each lobe of thyroid gland has its one pair.
�Secrete peptide hormone called parathyroid hormone (PTH) which increases calcium levels in blood so called hypercalcemic hormone.
�PTH stimulates bone resorption, and reabsorption of calcium from blood and reabsorption of calcium by renal tubules.
THYMUS GLAND
�Located on dorsal side of heart and aorta.
�Secrete peptide hormones called thymosins which play role in differentiation of T-lymphocytes (help in cell mediated immunity).
�Thymosins also produce antibodies and provide humoral immunity.
�Immunity of old people usually becomes weak as thymus gets degenerated with age.
ADRENAL GLAND
�Located at anterior part of each kidney.
�Has centrally located adrenal medulla and at periphery is adrenal cortex.
�Adrenal medulla secretes adrenaline (epinephrine) and nor adrenaline (nore- pinephrine), commonly called as catecholamines or emergency hormones or hormones of flight and fight.
�These hormones increase heart beat, rate of respiration, breakdown of glycogen thus increase blood glucose level, breakdown of lipids and proteins, alertness, raising of hairs, sweating etc.
�Adrenal Cortex (3 layers) : Zona reticularis (inner layer)
�Adrenal cortex secretes : Androgenic steroids : Zona fasciculata (middle layer) Zona glomerulosa (outer layer)
�Secreted in small amounts.
�Play role in growth of axial pubic and facial hair during puberty.
Glucocorticoids:
�Involved in carbohydrate metabolism.
�Stimulates gluconeogenesis, lipolysis and proteolysis.
�e.g., Cortisol which is also involved in cardio-vascu lar and kidney functions.
�It also suppresses immune response and stimulates RBC production. Mineralocorticoids :
�Regulate balance of water and electrolytes in body.
�e.g., Aldosterone which also helps in reabsorption of Na + and water excretion of K ions from renal tubules. + and phosphate
PANCREAS
�Has both exocrine and endocrine function.
�Contains about 1-2 million islets of langerhans which has glucagon secreting ?-cells and insulin secreting ?-cells.
�Glucagon : Peptide hormone, stimulates glycogenolysis by acting on liver cells. Also, stimulates gluconeogenesis. Hence called hyperglycemic hormone.
�Insulin : Peptide hormone, acts on hepatocytes and adipocytes to enhance cellular glucose uptake, stimulates conversion of glucose to glycogen (glycogenesis), so decreases blood glucose level called hypoglycemic hormone.
�Deficiency of insulin causes diabetes mellitus in which loss of glucose occurs through urine.
TESTIS
�A pair of testis composed of seminiferous tubules and interstilial cells is present in the scrotal sac of males.
�Leydig cells (interstitial cells) produce androgens (mainly testosterone) which regulate development and maturation of male accessory sex organs, formation of secondary sex characters and play stimulatory role in spermatogenesis. Male sexual behaviour (libido) is influenced by androgens.
(i) Ovary :�pair of ovaries which produce one ovum in each menstrual cycle are present in abdomen in females.
�Ovary composed of ovarians follicles and stromal tissue.
�Estrogen synthesised by growing ovarian follicles helps in stimulation of growth of female secondary sex organs, female behaviour, mammary gland development and female secondary sex characters.
�Ruptured follicle forms corpus luteum which secretes progesterone. Progesterone supports pregnancy and stimulates alveoli formation and milk secretion in mammory glands.
Hormones secreted by tissues which are not endocrine glands
(a) Heart : Atrial wall secrets Atrial Natriuretic factor (ANF) which decreases blood pressure by dilation of the blood vessels.
(b) Kidney : Juxtaglomerular cells secretes erythropoietin which stimulates erythropoiesis (RBC formation).
(c) Gastrointestinal tract : It secrets four peptide hormones.
�Gastrin : Acts on gastric glands and stimulates secretion of hydrochloric acid and pepsinogen.
�Secretin : Acts on pancreas and stimulates secretion of water and bicarbon- ate ions.
�Cholecystokinin (CCK) : Acts on pancreas and gall bladder to stimulate secretion of pancreatic juice and bile juice respectively.
Gastric inhibitory peptide (GIP) : Inhibits gastric secretion and motility.
Mechanism of hormone action : By hormone receptors of two kinds, i.e., (a) Located on membrane of target cell
�These are membrane bound receptors.
�Form hormone receptor complex .
? Leads to biochemical changes in tissue.
? Release of second messengers like
(cyclic AmP, IP [148] 3 , Ca etc.) which regulate cellular metabolism.
(b) Located inside the target cell
These are intracellular receptors.
�Hormones (steroid hormones, iodothyronines etc.) interact with them and cause physiological and developmental effects of regulating gene expression.
21, Neural Control and Coordination class 11
Neural Control and Coordination Notes For bio Download in pdf
Chapter 21 Neural Control and Coordination Download in pdf
|
Chapter 21 : Neural Control and Coordination
NCERT Notes For Class 11 Biology Download In PDF
POINTS TO REMEMBER
Action potential : A sudden change in the electrical charges in the plasma membrane of a nerve fibre.
Aqueous humour : The thin watery fluid that occupy space between lens and cornea in eye.
Blind spot : A spot on ratina which is free from rods and cones and lack the ability for vision.
Cerebrospinal fluid : An alkaline fluid present in between inner two layer of meninges.
Cerebellum : A part of hind brain that controls the balance and posture of the body.
Cochlea : A spirally coiled part of internal ear which is responsible for hearing.
Corpus callosum : A curved thick bundle of nerve fibres that joins two cerebral hemisphere.
Depolarisation : A condition when polarity of the plasma membrane of nerve fibre is reversed.
Endolymph : The fluid filled within membranous labyrinth.
Ecustachian tube : A tube which connect ear cavity with the pharynx.
Fovea : A area of highest vision on the ratina which contain only cones.
Meninges : Three sheets of covering of connective tissue wrapping the brain.
Grey Matter : This shows many convolutions which increase the amount of vital nerve tissue.
Medula oblongata : Posterior most part of the brain which is continuous with spinal cord and control respiration, heart rate, swallowing, vomiting.
Pons : Thick bundles of fibres on the ventral side of brain below cerebellum.
Foramen magnum : A big aperture in the skull posteriorly through which spinal cord emerges out.
Spinal cord : A tubular structure connected with medulla oblongata of brain and situated in the neural canal of the vertebral column, covered by meninges.
Synaptic cleft : A narrow fluid filled space which separates two membranes of the two neurons at the synapse.
Synaptic vesicles : These are membrane bound vesicles in the axoplasm of the axon terminal and these store neurotransmitter.
Neurotransmitter : These are chemicals stored in synaptic vesicles, diffuse to reach the membrane of next neuron for its stimulation.
Synapse : A physiological junction between axon of one neuron and dendrite of next neuron.
CNS ? Central neural system
PNS ? Peripheral neural system
ANS ? Autonomic neural system
Conduction of nerve impulse along axon Polarised membrane/Resting Potential In resting phase when neuron is not conducting an impulse, the axonal membrane is called polarised. This is due to difference in concentration of ions across the axonal membrane.
At Rest
� Axoplasm inside the axon contain high conc. of K and low conc. of Na .
� The fluid outside the axon contain low conc. of K + and high conc. of Na .
As a result the outer surface of axonal membrane is positively charged and inner + surface is negatively charged. The electric potential difference across the resting plasma membrane is called resting potential.
Action Potential : When a nerve fibre is stimulated, the permeability of membrane to Na + is greatly increased at the point of stimulus (rapid influx of Na ) and hence polarity of membrane is reversed and now membrane is said to be depolarised. The electric potential difference across the plasma membrane at that site is called action potential, which infact termed as nerve impulse. Depolarisation is very rapid, so that conduction of nerve impulse along the entire length of axon occurs in fractions of second.
Transmission of Impulses at Synapse
(i) At electrical synapses : Here the membrane of pre and post-syneptic neuron are in very close proximity. Electric current can flow directly from one neuron into other across these synapses, like impulse conduction along a single axon.
(ii) At chemical synapses : Here the membrane of pre and post-syneptic neuron are separated by fluid filled space called synaptic cleft. Neurotransmitter are involved here.
When an impulse arrives at the axon terminal, it stimulates the movement of the synaptic vesicles towards membrane and they fuse with the plasma membrane and release their neurotransmitter in the syneptic cleft.
These chemicals bind to specific receptors, present on the post-syneptic membrane.
Their binding opens ion channels and allow the entry of ion which generate new potential in post synaptic neuron.
Functions of parts of brain
Cerebrum : Centre of intelligence, memory and imagination, reasoning, judgement, expression of will power.
Thalamus : Acts as relay centre to receive and transmit general sensation of pain, touch and temperature.
Hypothalamus : Centre for regulation of body temperature, urge for eating and drinking.
Mid brain : Responsible to coordinate visual reflexes and auditory reflexes.
Cerebellum : Maintains posture and equilibrium of the body as well as coordinates and regulates voluntary movement.
Pons varoli : Relays impulses between medulla oblongata and cerebral hemisphere and between the hemisphere of cerebrum and cerebellum. Medulla oblongata : Centre that control heart beat, breathing, swallowing, salivation, sneezing, vomiting and coughing.
20, Locomotion and Movement Class 11
Locomotion and Movement Notes for Class 11 Download in pdf
Chapter 20 Locomotion and Movement Download in pdf
|
Chapter 20 : Locomotion and Movement
NCERT Notes For Class 11 Biology Download In PDF
POINTS TO REMEMBER
Arthritis : an enflamm atory joint diease characteresed by enflammation of joints.
Coccyx : tail bone formed by fusion of four coccygeal vertebrae in man.
Dicondylic Skill : A Skull with two occipital condyles.
Endo Skeleton : A skeleton present outside the body.
Fascicule : Bundles of muscles febers held together by connective tissue.
Fascia : Collagenous connective tissue layer that surrounds muscle bundles.
Floating ribs : The ribs that remain free anteriorly.
False ribs : The ribs whose sternal part are join to sternal part of a true rib.
Myoglobin : A red coloured pigment present in sarcoplasm of muscle.
Sarcolema : A portion of myofibril between two successive �Z� lines.
Sarcocolema : The plasma membrane of a muscle. Gout : Inflammation of joints due to accumulation of uric acid crystal. Suture : immovable joints between skull bones.
Synovial joints : Freely movable joints between limb bones. Patella : A sesamoid bone acting as kneecap
Intervertebral disc : Fibro carti lagenous pad present between the vertebrae and act as shock absorbers.
L.M.M : Light meromyosin
HMM : Heavy meromysoin
Types of Movement
1. Amoeboid movement : These movement takes place in phagocytes where leucocytes and macrophages migrate through tissue. It is affected by pseudepodia formed by the streaming of protoplasm (as in amocba)
2. Celiary movement : These movement occurs in internal organs which are lined by ciliary epithelium.
3. Muscular Movement : This movement involve the muscle fibers, which have the ability to contract and relex.
Properties of Muscle
(i) Excitability
(ii) Contractility
(iii) Extensibility
(iv) Elasticity
Types of Muscles
(a) Skeletal muscles or striated muscles :- These involved in locomotion and change of body postures. Thes are also known as voluntary muscles.
(b) Visceral muscles or smooth muscles :- These are located in inner wall of hollow visceral organ, smooth in appearance and their activity are not under control of nervous system.
(c) Cardiac muscles :- The muscles of heart, involuntary in nature, steriated and branched, These are uni nucleated.
Structure of myofibril
� Each myofibril consist of alternate dark and light band.
� Dark band :- contain myosim protien and is called A-band or Anisotroic band.
� Light band : - Contain actin protien and is called I Band or Isotropic band.
� I Band is bisected by an elastic fiber called �Z� line. Actin filament (thin flament) are firmly attached to the �Z� lines.
� Myosin filament (thick filament) in the �A� Band are also held together in the middle of �I� Band by thin fibrous membrane called �M� line.
� The portion between two successive �Z� lines is considered as functional unit of contraction and is called a sarcomere.
Mechenism of Muscle contraction : Sliding filament theory.
The contraction of musle fiber takes place by the sliding of actin (thin flament) on myosin ( thick filament).
� Muscle contraction is initiated by a signal sent by the CNS via a motor neuron.
� Impulse from motor nerve stimulates a muscle fiber at neuro muscular junctions.
� Neurotransmitter releases here which generates an action potential in sarcolema.
� These causes release of Ca ++ into sarcoplasm.
� These Ca binds with troponin, thereby remove masking of active site.
� Myosin head binds to exposed active site on actin to form a cross bridge, utilising energy from ATP hydrolysis.
� This pulls the acin filament towards the centre of �A� band. �Z� lines also pulled inward thereby causing a shortning of sarcomere i.e. contraction. �I� band get reduced, whereas the �A� band retain the length.
� During relexation, the cross bridge between the actin and myosin break. Ca pumped back to sarcoplasmic cesternae.
� Actin filament slide out of �A� band and length of �I� band increases.
� This returns the muscle to its original state.
19, Excretjory Products and their Elimnation class 11
Excretjory Products and their Elimnation Download pdf
Chapter 19 Excretjory Products and their Elimnation Download in pdf
|
Chapter 19 : Excretjory Products and their Elimnation
NCERT Notes For Class 11 Biology Download In PDF
POINTS TO REMEMBER
Ammonotelism : The animals which excrete ammonia are called ammonotelic and excretion of ammonia is known as ammonotelism eg Amoeba, sycon, hydra, liver fluke, tapeworm, Leech, Prawn, bony fishes etc.
Ureotelism : Excretion of urea is known as ureotelism and the animals which excrete urea are ureotelic animals eg. manmals, many terrertrial amphibians and marine fishes and sting rays etc.
Uricotelism : Excretion of uric-acid is known as uricotelism and the animals are called uricotelic eg. most insects , land snails, lizards and snakes and birds.
Nephrons : The structural and functional unit of kidneys. Each kidney contains about one million of nephrons.
Structure of Nephron : A nephron consists of Glomerulus, Bowman�s capsule, PCT (Proximal convo- luted tubule). JG A (Juxaglomerular Appartus) and the collecting duct. (Refer fig., 19.3, page 292
NCERT Text Book of Biology for Class XI
Structure of Kidney : Size 10-12 cm in length, 5-7 cm in width, 2-3 cm thick, average weight about 120-170 g
� The blood vessels, ureter and nerves enter in the kidney through hilum (a notch). The outer layer is a tough capsule.
� The outer zone of Kidney is cortex and the inner is medulla.
� The medulla is divided into few conical masses (medulllary pyramids) projecting into calyces.
� The cortex extends between medullary pyramids called columns of Bertini. Refer figure 19.2, page 292
NCERT - Class XI Biology
Glomerular Filtration : The filtration of blood in glomerulus, about 1100-1200 ml of blood is filtered by the kidney per minute.
Glomerular Filtration Rate (GFR) : The amount of filtrate formed by the kidney perminute. In a healthy individual it is about 125 ml/minute, ie 180 litres per day.
Types of Nephrons
(i) Juxtamedullary Nephron :- about 15% of total nephrons, Glomeruli are found in inner region of cortex, large in size, long loop of Henle and found deep in medulla, associated with recta, control plasma volume when water supply is short.
(ii) Cortical Nephron :- About 25% of total nephron mainly lie in renal cortex, glomeruli found in outer cortex, short loop of Henle, extends very little in medulla. They do not have vasa recta.
Functions of Tubules
(i) PCT :- absorption of all essential nutrients and 70-80% of electrolytes and water, helps to maintain the pH and ionic balance of body fluids by selective secretion of H + , ammoni and K into filtrate.
(ii) Henle�s Loop :- reabsorption in this segment is minimum, it plays a sig- + nificant role in maintenance of high as molarity of medullary interstitial fluid.
(iii) DCT :- conditional reabsorption of Na absorption of HCO 3 � and selective secretion of H + + and water takes place here, re- and K and ammonia to maintain the pH and sodium-potassium balance is blood.
(iv) Collecting duct :- Large amount of water is absorbed from this region to produce concentrated urine, it plays a role in maintenance of pH and ionic balance of blood by selective secretion of H + and K ions.
Mechanism of concentration of the Filtrate (Countercurrent Mechanism) : + Refer fig 19.6 page 296 (NCERT - Class XI Biology)
� This mechanism is said to be countercurrent mechanism because the out flow (in the ascending limb) runs parallel to and in the opposite direction of the inflow (in the descending limb).
� NaCl is transported by the ascending limb of Henle�s loop which is exchanged with the discending limb of vasa recta.
� NaCl is returned to the interstitium by the ascending portion of vasa recta.
� Henle�s loop and vasa recta as well as the counter current in them help to maintain an increasing osmolarity towards the inner medullary interstitium ie from 300 mOsmol/L in cortex to about 1200 mOsmol/L in inner medulla.
� Small amount of urea enter the thin segment of ascending limb of Henle�s loop which is transported back to the interstitium by the collecting tubule.
� This mechanism helps to maintain a concentration gradient in the medullary tubule interstitium.
� It helps in an easy passage of water from the collecting tubule to concentrate the filtrate ie urine.
Micturition : The expulsion of urine from the urinary bladder. It is a reflex process but can be controlled voluntarily to some extent in grown up children and adults.
� The CNS (Central Nervous System) sends the signal which cause the stretch- ing of the urinary bladder when it gets filled with urine.
� Inresponse, the stretch receptors on the walls of the bladder sends signals to the CNS.
� The CNS passes on motor massage to initiate the contraction of smooth muscles of the bladder and simultaneous relexation of the urethral spnicter causing the release of urine.
� An adult human excretes on an average 1 to 1.5 litres of urine per day.
� On an average 25-30 gram of urea is excreted out per day.
Role of other organs in excretion :
� Lungs :- removes CO (18L/day) and water.
� Liver :- secretes bilirubin, biliverdin etc. helps to eliminate these substances 2 alongwith cholesterol,vitamins, drugs and degraded steroid hormones through digestive wastes.
� Sweat and sebaceous glands :- These glands of skin help to eliminate small amount of urea, NaCl and lactic acid etc. through sweat while subaceous glands help to eliminate some substances like steroids, hydrocarbons and waxes through sebum.
� Saliva :- It can help to eliminate small amount of nitrogenous wastes.
Disorders of Excertory system :
� Uremia :- The accumulation of urea in blood due to malfunctioning of kidney.
� Hemodialysis :- The process of removal of urea from the blood artificially. In this process the blood from an artery is passed into dialysing unit after addding an anticoagulant like heparin. The blood passes through coiled cellophane tube surrounding by dialysing fluid. The nitrogenous wastes from the concentration gradient and the blood becomes clear.This blood is pumped back to the body through vein after adding anti-heparin to it.
� Renal calculi :- The formation of insoluble mass of crystallised salts (oxalates or phosphates of calcium.
� Glomerulonephritis :- Inflammation of glomeruli of kindney.
18, Body Fluids and Circulation class 11
Body Fluids and Circulation Notes for biology Download in pdf
Chapter 18 Body Fluids and Circulation Download in pdf
|
Chapter 18 : Body Fluids and Circulation
NCERT Notes For Class 11 Biology Download In PDF
POINTS TO REMEMBER
Blood : A special connective tissue that circulates in principal vascular system of man and other vertebrates consisting of fluid matrix, plasma and formed elements. Plasma : The liquid part of blood or lymph which is straw coloured, viscous fluid and contains about 90-92% of water and 6-8% proteins. Lymph : A clear yellowish, slightly alkaline, coagulable fluid, containing white blood cells in a liquid resembling blood plasma. Hear Beat : The rhythmic contraction and relaxation of the heart, which includes one systole (contraction phase) and one diastole (relaxation phase) of the heart. Heart beat count of healthy person is 72 times per minute. Cardiac output : The amount of blood pumped by heart per minute is called cardiac or heart output. The value of cardiac output of a normal personis about 72�70 = 5040 mL or about 5L per minute. Electrocardiograph : (ECG) The machine used to record electrocardiogram. Electrocardigoram ECG : The graphic record of the electric current produced by the excitation of the cardiac muscles. It is composed of a �P� wave, �QRS� wave (complex) and �T� wave (Refer fig. 18.3, page 286 (for a standard ECG) (NCERT class XI - Biology)
Lymph
The colouless mobile fluid connective tissue drains into the lymspatic capillaries from the intercellular spaces.
Composition : It is composed of fluid matrix, plasma, white blood corpuscles or leucocytes.
Functions :
(i) It drains excess tissue fluid from extra celluar spaces back into the blood.
(ii) It contain lymphocytes and antibodies.
(iii) It transport digested fats.
Human Heart
It is the mesodirmally derived organ situated in thoracic cavity in between the two lungs. Protected by pericardium.
� Four chambers - two (left and right) atria, and two ventricles (left and right)
�Inner- artrial septum separates the two atria and inter ventricular septum separates th two ventricles, while the atria & ventricles are separated by atrioventricular septum.
� The valves between right atrium and right ventricle is tricuspid while between left atrium and ventricle is bicuspid or mitral value.
� The openings of the right and the left ventricles into the pulmonary artery and the aorta are guarded by semilunar values. �
The values allow the flow of blood only in one direction, i.e., from atria to ventricles and from ventricles to pulmonary artery or aorta.
Rh (Rhesus) System : Discovered by Landsteiner and wiener in 1940. The antigen found on the surface of RBCs. The presence of this antigen is termed as Rh - positive (Rh ) and its absence as (Rh � + )
? SAN (Sino - artrial node) : A patch of tissues present in the right upper corner of the right atrium.
? AVN (Atrio Ventricular Node) : A mass of tissues seen in the lower left corner of the right atrium close to the atrio-ventricular septum.
Heart Valves
Tricuspid Valve : The valves formed of three musclar flaps or cups, which guard the opeing between the right atrium and the right ventricle.
Bicuspid Valve (Mirtral Valve) : The valves which guard the opeing between the left atrium and the left ventricle, made up of two flaps.
Semilunar Valves : The valves present at the opeing of the right and the left ventricles and allow the entry of blood into pulmonary artery and the aorta respectively.
Reading of ECG : �P� Wave represents the electrical excitation (or depolarisation) of the atria and leads to the contraction of both the atria.
�ORS� complex : represents the depolarisation of the ventricles, which imitiates the ventricular contraction
�T� Wave : represents the return of the ventricles from excited to normal state (repolarisation). The end of T-wave marks the end of sytole.
Double circulation : The passage of same blood twice throught heart in order to complete one cycle. eg.
(i) The blood pumped by the right ventricle (dioxygenated blood) is trans ported through pulmonary artery to lungs where CO 2 is exchanged with O through diffusion and returns back to the heart through pulmonary vein.
(ii) The oxygenated blood from left ventricle is trans ported through aorta to different body parts (cells and tissues) where O 2 is exchanged with CO through deffusion and then returned back to the heart through vena-cava. Disorders of circulatory System 2 Hypertension
(High Blood Pressure) : It results from narrowing of arterial lumen and reduced elasticity of arterial walls in old age. It can cause rupturing of capillaries. It is a silent killer.
Coronary Artery Disease : (CAD) Atherosclerosis The supply of the blood to heart muscles is affected. It is caused by deposits of ca, fat, cholesterol and fibrous tissues to make the lumen of arteries narrower.
Angina Pectoris : Caused due to arteriosclerosis, when no enought oxygen is reaching the heart muscle due to which the perosn experiences acute chest paind. Heart attack : Caused when the heart muscle is suddenly damaged by an inadequate blood supply.
Cardiac arrest : The state in which the heart stops beating.
Arteriosclerosis : The state of hardening of arteries and arterioles due to thickening of the fibrous tissue and consequent loss of elasticity. It Causes hypertension.
17, Breathing and Exchange of Gases class 11
Breathing and Exchange of Gases Notes Download in pdf
Chapter 17 Breathing and Exchange of Gases Download in pdf
|
Chapter 17 : Breathing and Exchange of Gases
NCERT Notes For Class 11 Download in PDF
POINTS TO REMEMBER
Breathing : (External respiration) The process of exchange of O from the atmosphere with CO 2 [110] 2 produced by the cells.
Inspiration : Oxygen from fresh air taken by lungs and diffuses into the blood.
Expiration : CO given up by venous blood in the lungs is sent out to exterior.
Respiration : The sum total of physical and chemical processes by which oxygen 2 and carbohydrates (main food nutrient) etc are assimilated into the system and the oxidation products like carbon dioxide and water are given off.
Diaphragm : A muscular, membranous partition separating the thoracic cavity from the abdominal cavity. The pressure contributed by an individual gas in a mixture of gases. It is represented as pO for carbondioxide.
Pharynx : The tube or cavity which connects the mouth and nasal passages with 2 oesophagus. It has three parts
(i) Nasopharynx (anterior part)
(ii) Oropharynx (middle part) and
(iii) Laryngopharynx (posterior part which continues to larynx)
Adam�s Apple : The projection formed by the thyroid cartilage and surrounds the larynx at the front of the neck.
Tidal volume (TV) : volume of air during normal respiration (500 ml.)
Inspiratory Resrve colume (IRV) : Additional volume of air inspired by a forcible inspiration. 2500 ml to 300 ml.
Expiratory Reserve Volume (ERV) : Additional volume of air, a person can expire by a forcible volume (RV) volume of air remaining in the lungs even after a forciable expiration (1100 mL to 1200 mL)
PURMONARY CAPACITES : Use in clinical diagnosis. Inspiratory capacity (IC) = (TV + 1 RV) Expiratory Capacity (E.C) = (T.V + ERV)
Functional Residual Capacity (FRC) = (ERV + RV) Vital Capacity (VC ) = ( ERV + TV + IRV ) or the maximum volume of air a person can breathe out after a forced inspiration.
Total Lung Capacity : It is cludes RV, ERV,TV and IRV or vital capacity + residual volume. Steps involved in respiration �
(i) Breathing or pulmonary respiration
(ii) Diffusion of gases (O 2 and CO ) across alveolar membrane.
(iii) Transport of gases by the blood
(iv) Diffusion of O 2 and CO 2 2 between blood and tissues.
(v) Utilisation of O by the cells for catabolic reactions and resultant release of CO . 2
MECHANISM OF BREATHING
Inspiration : It the pressure with is the lungs (intro pulmonary pressure) is less than the at maspheric pressure, ie there is negative pressure in the lungs with respect to the atmospheric pressure.
? The contraction of diaphragm increases the volume of thoracic chamber in antero-posterior axis.
? The contraction of external intercostal muscles lifts up the ribs and the sternum causing an increase in the volume of thoracic chamber in the dorso ventral axis.
? It causes an increase in pulmonary volume decrease the intra-pulnonary pressure to less than the atmospheric pressure.
? It forces the air out side to move in to the lungs, i.e, inspiration.
Expiration : Relexation of diaphragm and sternum to their normal positions and reduce the thoracic and pulmonary volume. It increases in intrapulmonary pressure slightly above the atmospheric pressure. It causes the expulsion of air from the lungs, i.e, expiration.
Transport of CO CO + HO 22 2 in the blood :- Carbonic anhydrase about 20% of CO 2 H CO (Carbonic acid) 23 is transported by combining with free amino group of Haemoglobin, in RBC.
HbNHCOOH (Carbamino haemoglobin) Carbonic anhydrase CO + HbNH 22 70% of CO 2 is transported as bicarbonates of sodium (NaHCO ) and potassium (KHCO ) 3
16, Digestion and Absorption Class 11
Digestion and Absorption Notes for Class 11 biology Download pdf
Chapter 16 Digestion and Absorption Download in pdf
|
Chapter 16 Digestion and Absorption
Notes For Biology Class11 Download In PDF
POINTS TO REMEMBER
Digestion : The process in alimentary canal by which the complex food is converted mechanically and biochemically into simple substances suitable for absorption and assimilation. Food : A substance which on taken and digested in the body provides mate- rials for growth, repair, energy, reproduction, resistance from disease or regulation of body processes.
Thecodont : The teeth embedded in the sockets of the jaw bone. e.g., in mammals. Diphyodont : The teeth formed twice in life time e.g., in mammals.
Peristalsis : The involuntary movement of the gut by which the food bolus is pushed forward.
Degluttition : The process of swallowing of food bolus. It is partly voluntary and partly involuntary.
Ruminants : The herbivours animals (e.g., cow, buffalo etc.) which have symbiotic bacteria in the rumen of their stomach which synthesize enzymes to hydrolyse cellulose into short chains fally acids.
Diarrhoea : The abnormal frequent discharge of semisolid or fluid faecal matter from the bowel.
Vomitting : The ejection of stomach contents through the mouth, caused by antiperistalsis.
Dysentry : Frequent watery stools often with blood and mucus and with pain, fever and causes dehydration.
Chyme : The semifluid mass into which food is converted by gastric secretion and which passes from the stomach into the small intestine.
Goblet cells : The cells of intestinal mucosal epithelium which secrete mucus.
Glissons capsule : The connective tissue sheath which covers the hepatic lobules of liver.
Hepatic lobules : The structural and functional units of liver containing hepatic cells which are arranged in the form of cords.
Sphincter of Oddi : The sphincter which guard the opening of common hepato-pancreatic duct.
Villi : The small finger-like folding in the innermost layer of the alimentary canal which increase the absorption surface area.
PEM : Protein Energy Malnutrition.
Basic steps of Holozoic Nutrition :
(1) Ingestion : Intake of food.
(2) Digestion : Breaking down of complex organic food materials into simpler, smaller soluble molecules.
(3) Absorption and assimilation : Absorption of digested food into blood or lymph and its use in the body cells for synthesis of complex components. (4) Egestion : Elimination of undigested food as faeces.
Digestive glands : (A) Salivary glands (found in mouth).
Three types are :
(i) Parotid
(ii) Sublingual
(iii) Submaxillary.
Secrete saliva which contains ptyalin (Salivary amylase)
(B) Pancreas : Secretes pancreatic juice.
(C) Liver : Secretes bile.
(D) Gastric glands : Secretes gastric juice.
(E) Intestinal glands : Secretes intestinal juice or succus entericus.
15, Plant Growth and Development Class 11
Plant Growth and Development Notes for Class 11 Download in pdf
Chapter 15 Plant Growth and Development Download in pdf
|
Chapter 15 : Plant Growth and Development
Notes For Class 11 Biology Download In PDF
POINTS TO REMEMBER
Abscission : Shedding of plant organs like leaves, flowers and fruits etc. from the mature plant.
Apical dominance : Suppression of the growth of lateral buds in presence of apical bud.
Dormancy : A period of suspended activity and growth usually associated with low metabolic rate.
Photoperiodism : Response of plant to the relative length of day and night period to induce flowering.
Phytochrome : A pigment, which control the light dependent developmental process.
Phytohormone : Chemicals secreted by plants in minute quantities which influence the physiological activities.
Senescene : The last phase of growth when metabolic activities decrease.
Vernalisation : A method of promoting flowering by exposing the young plant to low temperature.
Growth : An irreversible permanent increase in size of an organ or its parts or even of an individual. Abbreviations IAA Indole acetic acid NAA Naphthalene acetic acid ABA Abscissic acid IBA Indole-3 butyric acid 2.4D 2.4 dichlorophenoxy acetic acid PGR Plant growth regulator
Measurement of growth : Plant growth can be measured by a variety of parameters like increase in fresh weight, dry weight, length, area, volume and cell number.
Phases of growth : The period of growth is generally divided into three phases, namely, meristamatic, elongation and maturation.
(i) Meristematic zone : New cell produced by metotic division at root-tip and shoot tip thereby show increase in size. Cells are rich in protoplasm and nuclei.
(ii) Elongation zone : Zone of elongation lies just behind the meristematic zone and concerned with enlargement of cells.
(iii) Maturation zone : The portion lies proximal to the phase of elongation. The cells of this zone attain their maximum size in terms of wall thickning and protoplasmic modification.
Growth rate : The increased growth per unit time is termed as growth rate. The growth rate shows an increase that may be arithmetic or geometrical.
Differentiation : A biochemical or morphological change in meristemic cell (at root apex and shoot apex) to differentiate into permanent cell is called differentiation.
Dedifferentiation : The phenomenon of regeneration of permanent tissue to become meristematic is called dedifferentiation.
Redifferentiation : Meristems/tissue are able to produces new cells that once again lose the capacity to divide but mature to perform specific functions.
PHYTO HORMONE OR PLANT GROWTH-REGULATOR
Growth promoting hormones : These are involved in growth promoting activities such as cell division, cell enlargement, flowering, fruiting and seed formation. e.g., Auxin, gibberellins, cytokinins. Growth inhibitor : Involved in growth inhibiting activities such as dormancy and abscission. e.g., Abscisic acid and Ethylene.
a14, Respiration In Plants Notes for Class 11
Respiration In Plants Notes for Class 11 Download in pdf
Chapter 14 Respiration In Plants Download in pdf
|
Chapter 14 : Respiration In Plants
Notes For Biology Class 11 Download In PDF
POINTS TO REMEMBER
Aerobic respiration : Complete oxidation of organic food in presence of oxygen thereby producing CO , water and energy.
Anaerobic respiration : Incomplete breakdown of organic food to liberate 2 energy in the absence of oxygen.
ATPSynthetase : An enzyme complex that catalyses synthesis of ATP during oxidative phospho-relation.
Biological oxidation : Oxidation in a series of reaction inside a cell.
Cytochromes : A group of iron containing compounds of electron transport system present in inner wall of mitochondria.
Dehydrogenase : Enzyme that catalyses removal of H atom from the substrate.
Electron acceptor : Organic compound which recieve electrons produced during oxidation-reduction reactions.
Electron transport : Movement of electron from substrate to oxygen through respiratory chain during respiration.
Fermentation : Breakdown of organic substance that takes place in certain and ethanol. microbe like yeast under anaerobic condition with the production of CO.
Glycosis : Enzymatic breakdown of glucose into pyruvic acid that occurs in the cytoplasm.
Oxidative phosphorylation : Process of formation of ATP from ADP and Pi using the energy from proton gradient.
Respiration : Biochemical oxidation food to release energy.
Respiratory Quotient : The ratio of the volume of CO produced to the volume of oxygen consumed.
Proton gradient : Difference in proton concentration across the tissue membrane.
Mitochondrial matrix : The ground material of mitochondria in whichpyruvic acid undergoes aerobic oxidation through Kreb�s cycle. Abbreviations
ATP ? Adenosine tri phosphate
ADP ? Adenosine di phosphate
NAD ? Nicotinamide Adenine dinucleotide
NADP ? Nicotinamide Adenine dinucleotide Phosphate
NADH ? Reduced Nicotinamide Adenine dinucleotide
PGA ? Phosphoglyceric acid
PGAL ? Phospho glyceraldehyde
FAD ? Flavin adenine dinucleotide
ETS ? Electron transport system
ETC ? Electron transport chain
TCA ? Tricarboxylic acid
OAA ? Oxalo acetic acid
FMN ? Flavin mono nucleotide
PPP ? Pentose phosphate pathway
AEROBIC RESPIRATION
The overall mechanism of aerobic respiration can be studied under the following steps :
(A) Glycolysis (EMP pathway)
(B) Oxidative Decarboxylation
(C) Kreb�s cycle (TCA-cycle)
(D) Oxidative phosphorylation
Glycolysis : The term has originated from the Greek word
glycos = glucose
lysis = splitting or breakdown means breakdown of glucose molecule.
� It is also called Embeden-Meyerhof-Paranus pathway. (EMP pathway)
� It is common in both aerobic and anaerobic respiration.
� It takes place outside the mitochondria, in the cytoplasm.
� One molecule of glucose (Hexose sugar) ultimately produces two mol- ecules of pyruvic acid through glycolysis.
� During this process 4 molecules of ATP are produced while 2 molecules of ATP are utilised.
Thus net gain of ATP is of 2 molecules. Oxidative decarboxylation : Pyruvic acid is converted into Acetyle CoA in presence of pyruvate dehydrogenase complex.
Tri Carboxylic Acid Cycle (Kreb�s cycle) or Citric acid Cycle : This cycle starts with condensation of acetyle group with oxaloacitic acid and water to yield citric acid which undergoes a series of reactions.
� It is aerobic and takes place in mitochondrial matrix.
� Each pyruvic acid molecule produces 4 NADH + H + , one FADH , one ATP.
� One glucose molecule has been broken down to release CO and eight molecules of NADH + H + , two molecules of FADH and 2 molecules of ATP.
2 Electron transport system and oxidative phosphorylation : The metabolic pathway through which the electron passes from one carrier to another, is called Electron transport system and it is present in the inner mitochondrial membrane.
ETS comprises of the following :
(i) NAD and NADH + H
(ii) FAD and FADH
(iii) UQ
(iv) Cyt b, Cyt c 1 2 + , Cyt c, Cyt a and Cyt a .
Oxygen acts as final hydrogen acceptor. Oxidative phosphorylation takes 3 place in elementary particles present on the inner membrane of cristae of mitochondria. Synthesis of ATP from ADP and Pi using energy from proton gradient is called oxidative phosphorylation. In this process O acceptor and it get reduced to water. 2 2 2 is the ultimate electron
Total ATP Production | |
Process | Total ATP produced |
| 1. Glycolysis | 2ATP + 2NADH (6ATP) = 8ATP |
| 2. Oxidative decarboxylation | 2NADH (6ATP) = 6ATP |
| 3. Kreb�s Cycle |
2GTP (2ATP) + 6NADH22 (18ATP) + 2FADH (4ATP) = 24ATP22
|
13 Photosynthesis In Higher Plants Class 11
Photosynthesis In Higher Plants Notes For Class 11 Download pdf
Chapter 13 Photosynthesis In Higher Plants Download in pdf
|
Chapter 13 Photosynthesis In Higher Plants
Notes For Class 11 Biology Download In PDF
POINTS TO REMEMBER
Photosynthesis : Photosynthesis is an enzyme regulated anabolic process of manufacture of organic compounds inside the chlorophyll containing cells from carbon dioxide and water with the help of sunlight as a source of energy.
Historical Perspective Joseph Priestley (1770) : Showed that plants have the ability to take up CO 2 from atmosphere and release O .
Jan Ingenhousz (1779) : Release of O 2 by plants was possible only in sunlight and only by the green parts of plants.
Theodore de Saussure (1804) : Water is an essential requirement for photosynthesis to occur.
Julius Von Sachs (1854) : Green parts in plant produce glucose which is stored as starch.
T. W. Engelmann (1888) : The effect of different wavelength of light on photosynthesis and plotted the first action spectrum of photosynthesis. C. B.
Van Niel (1931) : Photosynthesis is essentially a light dependent reaction in which hydrogen from an oxidisable compound reduces CO to form sugar. He gave a simplified chemical equation of photosynthesis.
Hill (1937) : Evolution of oxygen occurs in light reaction.
Calvin (1954-55) : Traced the pathway of carbon fixation.
Hatch and Slack (1965) : Discovered C 4 pathway of CO fixation.
Site for photosynthesis : Photosynthesis takes place only in green parts of 2 the plant, mostly in leaves. Within a leaf, photosynthesis occurs in mesophyll cells which contain the chloroplasts. Chloroplasts are the actual sites for photosynthesis. The thylakoids in chloroplast contain most of pigments required for capturing solar energy to initiate photosynthesis. The membrane system (grana) 2 is responsible for trapping the light energy and for the synthesis of ATP and NADPH. Biosynthetic phase (dark reaction) is carried in stroma.
" Pigments involved in photosynthesis "
Chlorophyll a : (Bright or blue green in chromatograph). Major pigment, act as reaction centre, involved in trapping and converting light into chemical energy.
Chlorophyll b : (Yellow green)
Xanthophyll : (Yellow)
Carotenoids : (Yellow to yellow-orange) In the blue and red regions of spectrum shows higher rate of photosynthesis.
Light Harvesting Complexes (LHC) : The light harvesting complexes are made up of hundreds of pigment molecules bound to protein within the photosystem I (PSI) and photosystem II (PSII). Each photosystem has all the pigments except one molecule of chlorophyll �a� forming a light harvesting system (antennae). The reaction centre (chlorophyll a) is different in both the photosystems.
Photosystem I (PSI) : Chlorophyll �a� has an absorption peak at 700 nm (P700). Photosystem II (PSII) : Chlorophyll �a� has absorption peak at 680 nm (P680).
Process of photosynthesis : It includes two phases - Photochemical phase and biosynthetic phase.
(i) Photochemical phase (Light reaction) : This phase includes - light absorption, splitting of water, oxygen release and formation of ATP and NADPH.
(ii) Biosynthetic phase (Dark reaction) : It is light independent phase, synthesis of food material (sugars).
Photophosphorylation : The process of formation of high-energy chemicals (ATP and NADPH).
Cyclic photophosphorylation : Two photosystems work in series ? First PSII and then PSI. These two photosystems are connected through an electron transport chain (Z. Scheme). Both ATP and NADPH + H are synthesised by this process. PSI and PSII are found in lamellae of grana, hence this process is carried here.
Non-cyclic photophosphorylation : Only PSI works, the electron circulates within the photosystem. It happens in the stroma lamellae (possible location) because in this region PSII and NADP rectase enzyme are absent. Hence only ATP molecules are synthesised.
The electron transport (Z-Scheme) : In PS II, reaction centre (chlo. a) absorbs 680 nm wavelength of red light which make the electrons to become excited. These electrons are taken up by the electron acceptor that passes them to an electron transport system (ETS) consisting of cytochromes. The movement of electron is down hill. Then, the electron pass to PSI and move down hill further.
The splitting of water : It is linked to PS II. Water splits into H , O and electrons.
Chemiosmotic Hypothesis : Chemiosmotic hypothesis explain the mechanism of ATP synthesis in chloroplast. In photosynthesis, ATP synthesis is linked to development of a proton gradient across a membrane. The electrons are accumulated inside of membrane of thylakoids (in lumen). ATPase has a channel that allows diffusion of protons back across the membrane. This releases energy to activate ATPase enzyme that catalyses the formation of ATP.
Plants : ATP and NADH, the products of light reaction are used in synthesis of Biosynthetic phase in C food. The first CO 2 3 fixation product in C plant is 3-phosphoglyceric acid or PGA. The CO 2 3 acceptor molecule is RuBP (ribulose bisphosphate). The cyclic path of sugar formation is called Calvin cycle on the name of Melvin Calvin, the discoverer of this pathway.
Calvin cycle proceeds in three stages :
(1) Carboxylation : CO combines with ribulose 1, 5 bisphosphate to form 3 PGA in the presence of RuBisCo enzyme. 2
(2) Reduction : Carbohydrate is formed at the expense of ATP and NADPH.
(3) Regeneration : The CO acceptor ribulose 1, 5-bisphosphate is formed again . 2 6 turns of Calvin cycles and 18 ATP molecules are required to synthesize one molecule of glucose.
The C 4 pathway : C plants have special type of leaf anatomy, they tolerate higher temperatures. In this pathway, oxaloacetic acid (OAA) is the first stable product formed. It is 4 carbon atoms compound, hence called C 4 pathway (Hatch and Slack Cycle).
The leaf has two types of cells : mesophyll cells and Bundle sheath cells (Kranz anatomy). Initially CO 2 4 is taken up by phosphoenol pyruvate (PEP) in mesophyll cells and changed to oxaloacetic acid (OAA) in the presence of PEP carboxylase. Oxaloacetate is reduced to maltate/asparate that reach into bundle sheath cells. and formation of pyruvate (3C). In high CO The oxidation of maltate/asparate occurs with the release of O concentration RuBisCo functions as carboxylase and not as oxygenase, the photosynthetic losses are prevented. RuBP operates now under Calvin cycle and pyruvate transported back to mesophyll cells and changed into phosphoenol pyruvate to keep the cycle continue.
2 Photosrespiration : The light induced respiration in green plants is called photorespiration. In C 3 plants some O 2 binds with RuBisCo and hence CO fixation is decreased. In this process RuBP instead of being converted to 2 molecules of PGA binds with O to form one molecule of PGA and phosphoglycolate.
2 Law of Limiting Factors : If a chemical process is affected by more than one factor, then its rate will be determined by the factor which is nearest to its minimal value. It is the factor which directly affects the process if its quantity is changed.
Factors affecting photosynthesis :
1. Light
2. Carbondioxide
3. Temperature
4. Water
Subscribe to:
Posts (Atom)