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#1
11-09-2012, 01:12 AM
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شرح الباب الاول بالفديو لبيولوجي2
Types of nutrition Autotrophic Nutrition - Heterotrophic Nutrition" Holozoic-Parasites-Saprophytes - In green plants autotrophic nutrition includes two important processes that are Absorption of water& salts - Photosynthesis -  The processes of absorption of water * salts Adaptation of the root hairs to their function a- They are thin walled to allow the passage of salts & water b- They are large in number to increase the area of absorption c- The cell sap with high conic. solution to help the water to pass from the soil to the hair d- They produce viscous substance to move easily between the soil particles. & to stick to the soil Diffusion is the movement of molecules or ions from high concentrated medium to low concentrated, medium due o the continues free motion of molecules. as a drop of ink in water Permeability Different walls have different permeability , They can he classified into Permeable walls, Example, cellulose cell wall . Impermeable walls Example: lignin. subrin & cutin . Simi-permeable walls Example cellophane sheet & plasma membranes Osmosis: is the passage of water molecules from a high concentrated medium of water to a low concentrated medium of water, through a Simi permeable membrane. Osmotic pressure is the pressure that causes osmosis Imbibition:: is the ability of the colloidal substances to absorb water, swell& increase in volume. Cellulose in cell walls, pectin & proteins of the protoplasm are all colloidal substances Water move across the cortex till it reaches xylem vessels by three ways, From cell sap of one cell to another, by osmosis - From the cytoplasm of one cell to another through plasmodesmata - Water move through cell walls & the intercellular spaces by imbibition - Water move through cell walls & the intercellular spaces by imbibition - How is water directed to the xylem vessels & not to the phloem vessels The endodermal cell that face the phloem vessels are completely thickened with impermeable - subrin (Casparian strip) so water never go toward phloem Water moves through (the passage cells) by osmosis - absorption of mineral salts - Types of nutrients Essential nutrients Macro nutrients Micro nutrients ( C , O , H ) (K,P,Ca,S,Mg,Fe,N) (Al,Zn,Mn,Mo,Bo,Cl,I,Cu) The plants micro nutrients need them in small amounts to activate enzymes- Deficiency of Macro and Micro-nutrients would lead to Disturbances in plant growth - May stop plant growth completely - May cause no production of flowers or fruits - The mechanism of absorption of mineral salts Diffusion - Exchange ions - Active transport - It is the passage of any substance through the cell membrane against concentration gradient by the help of some chemical energy that released during aerobic respiration  An experiment on Nitella algae to prove active transport - An experiment to prove that active transport Need energy - How the Ions directed toward xylem -  When the ions reach the cytoplasm of the epidermal cells they diffuse freely & move from the cytoplasm of one cell to another through plasmodesma  By diffusion, by active transport (partially), through intercellular spaces of the cortex cells. Ions may be accumulated in the endoderm cells. Ions move from the endoderin cells to the xylem vessels by active transport Photosynthesis in green plants The importance s of photosynthesis are production of food as carbohydrates, proteins, fats and vitamins - It is the source of industrial row materials as wood, fibers ,fats. etc - It is the source of fuels such as coal, petroleum and natural gas - It is the source of oxygen required for respiration process - Raw materials required for photosynthesis * Water : is the source of hydrogen needed to reduce CO2 - CO2 is the source of carbon which reduced to form carbohydrate - Phosphorus: is required in producing energy compounds ATP - Magnesium: is required in the formation of chlorophyll molecules - Iron: is important for building up of some photosynthesis enzymes - Mineral salts: as nitrates, phosphates & sulphates to convert carbohydrates into proteins - Products of photosynthesis Monosaccharides are the main products of photosynthesis Oxygen the second product of photosynthesis The structure of the chlorophyll molecule, is C55 H72 O5 N4Mg - The Mg atom at centre - The rate of photosynthesis can be determined by Estimating the amount of carbohydrates. 1 gm/hour /m2 - counting the number of O2 bubbles which evolve in a unit time - the structure of the chloroplast ( Double thin membrane + Stroma + Grana )  The pigments of the chloroplast are  The adaptation of the leaf to carry out photosynthesis * The leaves arrangement to exposed to the maximum amount of sun light - The leaf blade is thin & flattened to absorb much light - The blade has midrib to keep it open & to carry water, salts & food - The stomata at the lower surface to exchange gases & to decrease water loss - The two surfaces of the leaf are covered with cutin to decrease water loss -   The adaptations of the leaf epidermal cells * The cells are barrel shaped to converge the light into the inner tissue - The cells are transparent to allow the passage of the sun rays - It is covered with cutin to protect the leaf against pests &decrease water toss - The cells are adjacent and compact to protect the inner tissues - The mesophyll lies between the upper & the lower epidermal layers Spongy tissue * It is irregular parenchyma cells - It has wide intercellular spaces - It has a few No. of chloroplasts - Its functions are store food, gas exchange and photosynthesis - palisade tissue cylindrical, parenchyma cells - has narrow intercellular spaces - has many chloroplasts - its function is the photosynthesis - The vascular tissue is formed of many vascular bundles distributed in the veins & venules * The vascular system in the leaf ** They are arranged inside the bundle towards to the upper epidermis, The protoxylem are - directed upwards Xylem vessels and separated by xylem parenchyma - The function of the xylem: support & supply the leaf with water&salts - Phloem lies toward to the lower epidermis, It consists of sieve tubes, companion cells and phloem parenchyma The function of the phloem it transport the soluble organic food from the mesophyll to the other plant parts - The Mechanism Of Photosynthesise The source of the released O2 Van Neil studied green purple bacteria which contain simple chlorophyll - Green purple bacteria use H2S as a source of Hydrogen instead of H2O  An experiment to prove that H2O is the source of O2 in photosynthesis The Chlorella algae was divided into two groups, each group was left to carry out photosynthesis as following A) The first group of the algae was left to absorb H2O formed of radioactive Oxygen O18 while the CO2 was formed of non-radioactive Oxygen O16 the results was as the following   The experiment was repeated after reversing the consitions H2O formed of normal O16 while CO2 has O "18" the results was as following light and dark reactions Blackman concluded that photosynthesis takes place in two main steps, light & dark reactions - The light reactions (the light is the limited factor ) When the chloroplast are exposed to light some electrons gain energy and move from lower energy level higherone ,so the light energy change into potential chemical energy The chlorophyll Part of the active chlorophyll energy is used in splitting H2O into H + NADP = NADPH2. & O2 releases The other part of the energy change ADP into ATP  Dark Reaction (The temperature is the limited factor) In stroma CO2 is reduced by H2 which is carried on NADPH2 and the energy stored in ATP molecules into carbohydrate Melvin Calvin experiment The first stable compound produced during photosynthesis process is PGAL formed of 3 carbon atoms Phosphoglyceraldehide  The importance of PGAL It is used as the source of energy in cellular respiration - It store in the form of starch - It is used in the formation of protein and fats - Heterotrophic nutrination ! Digestion: is the conversion of large food molecule or polymers (porteins starch and fats) into smaller ones or monomers (amino acids, glucose, fatty acids and glycerol) in a process catalyzed by enzymes The enzyme It is a proteinic substance has the properties of a catalyst & it has a specific ability to activate particular chemical reaction Types of mechanisms of enzyme action Breaking down - Building up - Properties of enzymes They are specific in their function - The enzyme is still as it is at the end of the reaction - Some enzymes may have a reversible effect - Enzyme only accelerate’ the rate of the reaction until it reaches a case of equilibrium - Some enzymes are secreted ‘by the cells in an inactive state - Enzyme can be used over and over again - the enzyme is affected by the temperature and PH -  The steps of digestion Digestion in mouth buccal digestion  In the oesophagus The oesophagus has glands to secrete mucus only to help in swallow food Digestion in the stomach gastric digestion The stomach wall has 2 types of glandular cells that are cells secretes HCl - Cells secretes Pepsinogen enzyme - The functions of HCl - ( It makes the stomach medium acidic (1.5 : 2.5 PH - It kills the microbes which enters into the stomach with the food - it activates Pepsinogen into Pepsin -  Q. Why does not the stomach digest itself Digestion in the small intestine A) The bile it is not an enzyme) The bile emulsifies fats by decreasing its surface tension to increase the area which exposed to the digestive enzyme The pancreatic juiceNaHCO3 - Which neutralizes the acidic Chyme & creates an alkaline medium Pancreatic amylase which hydrolysis the remaining of starch into maltose -  Trypsinogen inactive - it becomes active by the help of Enterokinase enzyme which is secreted from the ileum  Trypsin hydrolysis the remaining of proteins & converts them into polypeptides  Lipases They hydrolysis emulsified fats into fatty acids & glycerol -  C) The intestinal juice Peptidases They are a group of enzymes that hydrolysis polypeptides into amino acids -  Enzymes that hydrolysis disaccharides into monosaccharides -  Absorption of digested food Absorption is the passage of digested food to the blood & lymph through the epithelial cells of the Ileum The absorbed food passes through 2 routes which are * Lymphatic route -  The structure of the wall of the small intestine * Blood route - Metabolism It is the process in which the body benefits from the digested - food which absorbed thorough the digestive system - Metabolism = Anabolism + Catabolism -  Anabolism Anabolism is the conversion of small food molecule (monomers) into larger ones called polymers The sugars change into starch, which stored in the form of glycogen in the liver or muscles - Amino acids change into protein - Fatty acids and glycerol change into fats that stored in the body specially the skin - Catabolism It is the oxidation process of the absorbed food specially sugar to release the energy that needed by the body to carry out all vital activities  
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#2
11-09-2012, 01:27 AM
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Summary:
Pulmonary circulation Rt. Ventricle ---> pulmonary artery ---> Lungs ---> 4pulmonary vein ---> Lt Atrium 2- Systematic circulation Lt. ventricle ---> aorta ---> body organs ---> superior & inferior VC. ---> Rt. atrium 3- Hepatic portal circulation Villi blood capillaries ---> hepatic portal V. ---> hepatic V. ---> Inf.V.C --->Rt. Atrium Formation of the blood clotting a ) Blood platelets + destroyed cells -- clotting factors--> thromboplastin b ) Prothrombin --- Thromboplastin +clotting factors, Ca++ --> thrombin c ) Fibrinogen --- thrombin--->Fibrin Why blood does not clot inside blood vessels Because 1. Blood runs inside blood vessels in a regular speed and does not slow down. 2. Blood platelets slide easily inside the blood vessels in order not to be broken. 3. The liver secretes heparin to prevents the conversion of prothrombin into thrombin  An Experiment: to show that water ascent through Xylem vessels Apparatus: as diagram. Steps of experiment 1. Fill a test tube with eosin solution. 2. Carefully remove a small flowering plan from the soil and immerse the plant roots in the eosin solution. 3. Close the tube with a cotton wool plug. 4. Keep the tube in a vertical position for a few hours. 5. Cut a thin transverse section of the plant stem, and examine the section under the microscope. Observation 1. The leaf petioles and its veins change to pink. 2. Under the microscope, xylem tissue only is stained by eosin. Conclusion 1. Water is absorbed by roots. 2. Water ascent through xylem tissue of the stem to the leaves. 
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#3
11-09-2012, 01:28 AM
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الثاني
 Definition It is the entrance of the required material to the organism's body Examples of transportation among iving organisms In algae (primitive plants) H2O & CO2 & salts move from * one cell to another by diffusion & active transport. In primitive animals as protozoa & hydra, transportation occurs * by diffusion T.S. in Dicot. Stem Epidermis * Cortex ( Collenchyma - parenchyma - starch sheath ) * Vascular cylinder : Pericycle - vascular bundles - Pith * note : vascular bundles { Phloem - Cambium - Xylem } in  Phloem consists of sieve tubes, companion cells and phloem parenchyma * It carry the high - energy food from the leaves to all the plant parts Cambium is meristematic cells produce secondary phloem outwards and secondary xylem inwards Xylem consistes of vessels , tracheides & xylem parenchyma It carry water and salts from the root to the leaves and support the plant  The adaptation of xylem tissue to carry out its functions 1- The elongated cylindrical cells joined end to end to form vessels 2- The transverse walls disappear to facilitate the movement of H2O & salts. 3- The cells are hollow & devoid of protoplasm to carry H2O & salts. 4- Their walls are thickened with lignin to prevent the water to get out of the vessels and support the plant. 5- The unthickened Pits to allow the water to move at the two sides. the factors that are responsible for the ascent of sap 1- Root pressure theory G.R.F. The root pressure can not explain the ascent of sap along the xylem vessels Ans. Because: 1- Root pressure does not exceed two atmospheric pressure. 2- Some plants as Pinus (Conifers) have no any root pressure. 3- The force of the root pressure is affected by the environmental factors. 2- Imbibition theory: G.R.F Imbibition can not explain the ascent of sap Ans. Because the experiments prove that the sap ascends through the cavity of the xylem vessels & not along their lignified walls 3- The theory of capillary G.R.F. Capillary can not explain the ascent of sap Water rises inside the narrowest vessels more than 150 cm. So capillary is considered as weak and secondary force affecting the ascent of sap 4- Cohesive force, adhesive force and transpiration pulls theory a- The cohesive force is due-to the strong attraction between the water molecules inside the vessels. This helps the water column to exist inside the vessel. b- The adhesive force is due the strong attraction between water molecules & the walls of the vessels. This helps the water column to resist gravitational force. c- the transpiration pull by which water rises inside the vessels. This helps the continues column of water to move upwards. The conditions should be fulfilled in the xylem vessels in order to be capable for the transportation of the raw materials 1- The vessels must be capillary tubes. 2- The walls should have high adhesive force to water molecules. 3- The water column should be devoid of air bubbles, the air bubbles cuts, the water molecules, so that the water column falls down due to gravity. G.R.F. The failure of transporting a cultivated plant part after being moved from the soil & left exposed to the sun rays for long time Because water evaporates through stomata, then air enters through the cut surface to fill the xylem vessels breaking the water column. As a result the plant wilts & dies even after recultivation Explain how does the sap rise inside the xylem vessels 1- Transpiration decreases the humidity in the air chambers ,so the cells around the air chambers evaporate water to replace the lost water from the chambers So that increase the concentration inside the cells .  3- Water inside the vessels are pulled up from stem & root xylem as they are connected 4- When water is pulled up in the root vessels until reach the vascular cylinder of the root and also pull water from the root hairs so the concentration inside the root hairs increase and increase the osmotic pressure thus water is absorbed from the soil. Experiments to prove that manufactured food is transported along phloem Rapidan & Bohr’s experiment: 1945 * Leaves of bean plant were exposed to CO2 formed of radioactive C14 to carry out photosynthesis. Radioactive carbon was then detected inside the phloem vessels up & down the stem Mittler’s experiment * By separating the body of the Aphid insect from the proboscis, during its feeding on manufactured plant food & by ****yzing the contents of the insect’s stomach it was found that this solution is formed of sucrose & amino acids. Miller found that the tip of the proboscis dip into the phloem sieve tubes which contains sucrose & amino acids.. The transportation of food by the phloem: cytoplasm streaming theory Thain & Canny could see cytoplasm strands which carry food particles extending along the sieve tubes . Transportation of food is due cytoplasm streaming inside the tubes moves up & down through the pores in the sieve plates by active transport which require energy (ATP). therefore it is affected by temperature & oxygen supply ,the transportation inside the phloem slows down in the conditions of low temperature or lack of oxygen Transport In Animals   Human circulatory system is a closed circulatory system because its blood * . vessels form a complete circuit The heart is surrounded by a double membrane Called pericardium to protect the * . heart against Shocks & also to facilitate the hearts Pumping action Tricuspid valve : it has 3 flaps It allow the blood to pass from the right atrium to the right ventricle and prevent it to return back Mitral valve Bicuspid valve : it has 2 flaps It allows the blood to pass from the left atrium to the left ventricle and prevent it to return . The Simi-lunar valve : It has 3 pockets It allows the blood to pass from the right ventricle to the lunges through the * Pulmonary artery or from the left ventricle to the body organs through the aorta artery and prevent it to return to the heart Aortic Simi-lunar valve: It has 3 pockets It allows the blood to pass and prevent it to return to the heart The internal valves of vein can be observed in the arm veins when the arm is tied tightly with a bandage (tourniquet) {discovered by William Harvey} 3- Blood capillaries microscopic blood vessels formed of one raw of thin epithelial cells connect between arterioles & venules its diameter is 7 : 10 microns the thickness of the wall is about 0.001 micron المرفق 031.JPG لم يتم العثور على Comparison between Arteries and veins  1- It is a liquid tissue consists of plasma & cells (RBCs, WBCs & blood platelets) 2- It is a red viscous liquid due to the presence of hemoglobin. 3- It is weakly alkaline (pH=7.4) 4- The human’s body contains about 5 : 6 liters blood The functions of the blood 1- It transports digested food,O2, CO2 ,Nitrogenous wastes, hormones &some enzymes 2- It regulates metabolic activities. 3- It regulates the body temperature. 4- It regulates the internal environment of the body, such as osmotic potential, & PH 5- It protects the body against microbes & by the lymphatic system. 6- It protects itself against bleeding by the formation of the blood clot. Comparison between Erythrocytes and Leucocytes  They are chemical substance discover the harmful foreign materials and stop their action to be harmless. The heart beating 1) The sino-atrial node (pace maker) S-A node It is a specialized cardiac fibers buried in the right atrium between the two veins. It sends impulses to the muscles of the 2 atria causing their contraction. 2) The atrio-ventricular node A-V node It lies at the connection between the atria & the ventricles . It receives electrical impulses from the sino-.atrjal node and send them through special fibers (named Hess & Perkinjs apparatus) to contract the ventricles . It is connected to two nervous a) The vagus nerve inhibits the rate of the heart beating. The Heart sounds Lubb-Dubb ….. Lubb-Dubb….. Lubb-Dubb….. 1- Lubb sound It is long & low pitched It heard during the contraction of the ventricles due to the closure of the bicuspid & tricuspid valves. 2-Dubb sound It is short & high pitched It heard during the contraction of the atria & relaxation of the ventricles due to the closure of the pulmonary & aortic Simi-lunar valves Blood Pressure Systolic blood pressure is the maximum blood pressure in the arteries that close to the heart during the contraction of the ventricles. Diastolic blood pressure is the minimum blood pressure in the arteries that close to the heart during the relaxation of the ventricles. Measuring the Blood Pressure Sphygmomanometer is an instrument that used to measure the blood pressure Sphygmomanometer give 2 numbers as 120/80 mm Hg in normal youth The no.120 indicate Systolic blood pressure but 80 indicate the diastolic blood pressure. Systolic blood pressure is the maximum blood pressure in the arteries that close to the heart during the contraction of the ventricles 120 mm Hg but it decrease until reach 10 mm Hg in blood capillaries and veins therefore the presence of the internal valves of vein help the blood to return back to the heart . The blood pressure increase gradually in old ages so, it needs to treat before it reaches the dangerous cases. The Blood Circulation  It starts from right ventricle & ends at left atrium. When the right ventricle contracts, the deoxygenated blood rushes into the pulmonary artery and the Simi-lunar valve is closed preventing the returning back The pulmonary artery divide into two branches, each branch divides again into small branches till it ends at blood capillaries around alveoli. Through the blood capillaries water vapour & CO2 come out the blood & O2 get into the blood This is called exchange of gases so, the blood now become oxygenated. The blood returns from the lungs to the left atrium through the 4 pulmonary veins. The left atrium contracts pushing the blood down to the left ventricle through the bicuspid valve. 2- Systematic circulation  It starts from the left ventricle & ends at the right atrium. When the left ventricle contracts the bicuspid valve shuts & Oxygenated blood rushes into the aorta & does not go back to the heart.GR The aorta branches into arteries. Each artery enters to an organ of the body and endat a network of blood capillaries distributed between the body tissues & cells Exchange of material between the blood & the cells takes place where the cells receive O2 & foodstuffs from the blood & the bloodn receives CO2 , H2O & wastes Exchange of substance takes place by diffusion & active transport through the walls of the blood capillaries 3- Hepatic portal circulation  The blood capillary of the villi, carrying digested food stuffs, collect to form larger venules, These venules form a large vein called hepatic portal vein that enters into the liver The hepatic portal vein also receives other veins coming from the pancreas, the spleen & the stomach. The hepatic portal vein branches into smaller venules that end at blood capillaries distributed between the hepatic cells, Through the blood capillaries sugars & amino acids diffuse into the hepatic cells where some changes occur. The blood leaves the liver through the hepatic vein to join the upper part of the inferior vena cava just before it opens at the right atrium
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#5
11-09-2012, 01:35 AM
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http://www.youtube.com/watch?feature...&v=pHNc-8GaURU http://www.youtube.com/watch?feature...&v=mc9gUm1mMzc http://www.youtube.com/watch?feature...&v=Yli0FcsQmuI
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#6
11-09-2012, 01:43 AM
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الثالث
 Summary of Respiration in living organisms Cellular respiration it is the process by which energy is extracted from the chemical bonds in the food molecules, Structure of ATP   1- Glucolysis occurs in cytosole 2-Krebs cycle occurs in Mitochondria Q. GR.. Krebs cycle does not need Oxygen Ans. Because oxidation of organic molecules takes place by the release of electrons, The released electrons & protons are received directly by the Co-enzymes NAD+ & FAD. Oxidative Phosphorilation It is the formation of ATP molecules from ADP molecules by using the energy that released when the electrons descend step by step down the energy levels of the Cytochromes during the electron transport . 3-Electron transport occurs in Mitochondria        Structure and adaptation of the trachea[/size] a- It is supported by cartilaginous rings to prevent it against collapse b- It is lined with cilia to reject foreign bodies. c- It is divided into two bronchi which open at each of the two lunges. The mechanism of human respiration (Ventilation of the lunges) o Inspiration (breath in) (Inhalation) o * The intercostal muscles contract where the ribs move upwards and diaphragm muscle - contract downwards, this leads to increase the size of chest cavity while its internal pressure decrease, this causes air to get into the lungs through the nose.. 2- Exhalation or expiration  Comparison between inhalation and Exhalation  This will help: a. In warming the new air coming to the lungs. b. In protecting the alveoli against collapse. √ The respiratory system in man plays an important role in the excretion of 500cm3 water, CO2 & volatiles A) An Exp. to prove that the non green parts of the plant respire 1- Dry seeds do not respire actively, so the volume of air in retort no.(1) not changes 2. Germinating seeds respire actively, in retort no. (2) but CO2 is not absorbed by NaCl 3. When germinating seeds in retort no.(3) respire, the released CO2 absorbed by KOH sol. So, the KOH rises up in the stem of the retort.  An Exp. to prove that the green parts of the plant respire In 1. The green plant respires & releases CO2 to the air. This CO2 turns lime water to milky solution.  An experiment to prove alcoholic fermentation: Observation: 1. Gas bubbles are seen on the surface of the solution 2. Lime water becomes turbid . Conclusion: Turbidity of lime water proves that CO2 has been evolved as a result of respiration of yeast. Seeds of Angiosperms have the power to respire anaerobically if they are kept under anaerobic conditions 
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#8
11-09-2012, 01:46 AM
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#9
11-09-2012, 01:47 AM
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