GCSE BIOLOGY 100% correct

GCSE BIOLOGY 100% correct An action by an organism or part of an organism causing a change of position or place *ans*Define movement The chemical reaction that breaks down nutrient molecules in living cells to release energy *ans*Define respiration Glucose+oxygen-water+carbon dioxide *ans*Respiration word equation *ans*Respiration symbol equation Ability to detect or sense changes in the environment and to make responses *ans*Define sensitivity A permanent increase in size and mass by an increase in cell number or cell size *ans*Define growth Processes that make more of the same kind of organisms *ans*Define reprouction Removal from organisms of toxic materials, the waste product of metabolism and substances in excess requirement *ans*Define excretion Taking in of nutrients which are organic substances and mineral ions, containing raw materials or energy for growth and tissue repair, absorbing and assimilating them *ans*Define nutrition The smallest structural and functional unit of an aorganism *ans*Define cell -Only plant cells have chloroplasts and cell walls -Shape of plant cell is more regular -Animal cells store carbohydrates as glycogen, plant cells store carbohydrates as starch *ans*State differences between the typical animal and plant cell Contains DNA (Genetic material), which controls cell activity *ans*Function of nucleus (cell) Where chemical reactions take place *ans*Function of cytoplasm Partially permeable membrane which controls substances that move in and out of the cell *ans*Function of cell membrane Strengthens and protects the cell *ans*Function of cell wall Contains chlorophyll which absorbs light energy for photosyntheis *ans*Function of chloroplast Carbon dioxide+water-Oxygen+glucose *ans*Word equation for photosynthesis *ans*Symbol equation fo photosynthesis Filled with cell sap which helps keep the cell turgid *ans*Function of vacuole Carries oxygen around the body to all respiring tissues (Contains haemoglobin which picks up oxygen) *ans*Function of red blood cell -Biconcave shape (Higher surface area) -No nucleus (Can move around more easily and allows the cell to hold more oxygen) *ans*How the red blood cell is suitable for its function To absorb water and mineral ions for the plant (vis osmosis *ans*Function of root hair cell -Elongated section to its main body (Higher surface area) -Membrane of the root is semi permeable (only water and minerals can go through) *ans*How the root hair cell is suitable for its function The net movement of molecules form a region of high concentration to a region of lower concentration down a concentration gradient (Result of random movement/brownian motion) *ans*Define diffusion -Necessary for gas exchange in living organisms -Necessary for photosynthesis *ans*Importance of diffusion in gases -Absorption of minerals in plants (minerals salt needs to dissolve in water) -Necessary for excretion (pee) *ans*Importance of diffusion in water as a solvent The diffusion of water molecules from a region of high concentration to a region of lower concentration through a semi permeable membrane *ans*Define osmosis -Water enters the root hair cell through osmosis -If vacuoles aren't full of water the cell will become flaccid causing the plant to will *ans*Osmosis in plant cells -If surrounded with high water potential, water will enter the cell, if to much water ends up in the cell it will burst -If surrounded with low water potential, water in cytoplasm will diffuse outwards causing the cell to shrink *ans*Osmosis in animal cells Proteins that function as biological catalysts (speeds up reaction in living cells) *ans*Define enzyme A substance on which enzymes act on *ans*Define substrate molecule A region on an enzyme which binds to the substrate during a reaction *ans*Define active site An enzyme has to be the right shape for the substrate to fit into. An enzyme will only accept 1 substrate (1 specific chemical reaction) *ans*Explain the lock and key mechanism for enzymes -As temperature increase so does the rate of reaction, up to a certain point. This point is known as the "optimum temperature". If the temperature goes above this enzyme activity will decrease (denature) -If the temperature is to low the enzyme will be dormand *ans*Temperatures effect on enzymes -Different enzymes work best at different PH s -If the PH is to low OR to high the enzyme will denature *ans*PHs effect on enzymes Breaks down protein *ans*Function of protease Breaks down starch *ans*Function of amylase Breaks down fats and oils *ans*Function of lipase Change in the structure of the enzyme *ans*Denature Glucose *ans*What is starch and glycogen made up of Amino acids *ans*What is protein made up of Fatty acids and glycerol *ans*What are fat and oils made up of Iodine solution -Posotive:Blue black -Negative:Orange yellow *ans*Test for starch Benedict solution -Posotive:Red -Negative:No change *ans*Test for sugars Oxygen, carbon and hydrogen *ans*Chemical elements that make up carbohydrates Oxygen, carbon and hydrogen *ans*Chemical elements that make up fats Oxygen, carbon, hydrogen, nitrogen and sulfur *ans*Chemical elements that make up proteins Gives the body energy -found in starch and sugars *ans*Function of carbohydrates Provides concentrated sources of energy and helps insulate the body in cold weather -Saturated fats obtained from animal sources (eg. butter) -Unsaturated fats come from vegetable sources (eg. sunflower oil) *ans*Functions of fats Assists in growth and repair -Found in animal products (eg. Meat, Fish, Cheese, milk) *ans*Function of proteins -Keeps skin healthy -Protects cell and helps absorb iron -Found in fruits and vegetables *ans*Function of vitamin C -Helps absorb calcium -Keeps teeth and bones strong -Found in dairy products and eggs *ans*Function of vitamin D Needed for blood production (production of haemoglobin) -Found in red meat and liver *ans*Function of iron -Keeps bone and teeth strong -Found in dairy products and fish *ans*Function of calcium Forms 70% of the human body. In cells, organs and tissues; helps regulate temperature and maintenance of other bodily functions *ans*Function of water in the human body Indigestible part of food. -Provides bulk for feaces and keeps the digestive system healthy -Found in cereal, fruits and vegetables *ans*Fibre Scurvy (Bleeding gums and lost of teeth) *ans*Vitamin C: Deficiency symptoms Rickets (Bones stop hardening properly) *ans*Vitamin D: Deficiency symptoms Anaemia (Reduction in red blood cell or haemoglobin level) *ans*Iron: Deficiency symptoms Poor bone development *ans*Calcium: Deficiency symptoms Micro organisms are added to milk, where the bacteria ferment (breakdown) the glucose present in the milk to lactic acid which causes milk to clot making yogurt *ans*Describe the manufacture of yogurt Fundamental process which plants manufacture carbohydrate from raw materials using energy from light -Chlorophyll inside the chloroplast traps light and converts it into chemical energy (Fuel needed for photosynthesis) *ans*Define photosynthesis Put the leaf in warm ethanol until it becomes colourless (Chlorophyll dissolves) *ans*Investigating the absence of chlorophyll (photosynthesis) Place airtight seal with soda lime in it around the leaf stalk *ans*Investigating the absence of CO2 (photosynthesis) Clip black paper onto both sides of the leaf *ans*Investigating the absence of light (photosynthesis) You test for starch 1) Boil leaf in water for 2 minutes (break down cell wall) 2) Warm leaf in ethanol until colourless (Gets rid of chlorophyll which masks observation) 3) Dip leaf into warm water (to soften brittle leaf and allow penetration by iodine solution) 4) Add iodine solution to the leaf -Blue-black: Positive -Orange-brown: Negative *ans*How do you check if photosynthesis has occurred Water is absorbed into the roots via osmosis. Water is transported up the xylem where it is used for different purposes *ans*Describe intake of water in plants Stomata allows carbon dioxide into the leaf (gas exchange) *ans*Describe the intake of CO2 in plants Waxy cuticle Upper epidermis Palisade mesophyll Spongy mesophyll Lower epidermis Stomata *ans*Describe the structure of a dicotyledonous leaf Layer on the surface of the leaf which reduces water loss -Thicker on the upper surface *ans*waxy cuticles Complete covering which is one cell thick -Transparent to allow free passage of light -Prevents entry of disease causing organisms such as bacteria and fungi *ans*Upper epidermis Tall thin cells arranged in columns and separated by very narrow airspaces -Cells contain many chloroplasts *ans*Palisade mesopyll Losely packed cells that are covered which a thin layer of water -Air spaces aid the diffusion of gas through the leaf -Air spaces are saturated with water vapour so water diffuses out of the leaf *ans*Spongy mesophyll Miniature pores that allow the entry of CO2 and the exit of oxygen -Mainly present in the lower epidermis (less exposed to the suns radiation, evaporation kept to a minimum) -Stomata can be closed when no CO2 intake is needed (In the dark; guard cells shut, covering the pore) *ans*Stomata Majority of photosynthesis occurs in the palisade mesophyll (palisade cells contain many chloroplasts) *ans*Describe the distribution of chlorophyll -Stomata allows gases to go in and out of the leaf -Air spaces between the mesophyll cells allow gases to pass through *ans*Gas exchange in plants Makes amino acids which is needed to make protein -Nitrate deficiency will cause stunted growth *ans*Uses of nitrate ions in plants Makes chlorophyll which is needed for photosynthesis -Chlorophyll molecules have a central magnesium ion -Magnesium deficiency will cause leaves to turn yellow *ans*Use of magnesium ions in plants Increases yield by providing plants with more protein increasing growth and repair -Overuse can cause eutrophication *ans*Uses of nitrogen containing fertilisers -Fertilizer leak into lake/rivers causing algae to grow -Algae blooms preventing sunlight from reaching other plants -As plants die it decomposes by bacteria (this process uses up oxygen) -Once a lot of oxygen is being used up, other creatures such as fish will not be able to live causing the water source to become stagnant *ans*Eutrophication is Condition where certain nutrients of a balanced diet are missing, in excess or taken in wrong proportions -Causes starvation, coronary heart disease, constipation and obesity *ans*Malnutrition Severe deficiency of energy, nutrients or vitamin. -Prolonged starvation can lead to organ damage or death *ans*Stravation Intake of to much fatty foods which leads to high cholesterol levels -Causes certain parts in the coronary artery to be clogged with cholesterol; prevents proper blood flow (oxygen and nutrients are unable to be transported across the body) *ans*Coronary heart diesease The obstruction of bowel movements -Caused by lack of fibre and water intake *ans*Constipation When a persons body weight is 20% above the standard body weight -Caused by an over abundance of calorie intake *ans*Obesity 1) Mouth 2) Esophagus 3) Stomach 4) Small intestine 5) Large intestine *ans*Order of the digestive system track Where food enters *ans*Mouth Secretes amylase (enzyme which breaks down starch) -Allows substance to be digested more easily *ans*Salivary gland Muscle lined tube which connects the throat the the stomach *ans*Esophagus Muscular bag which stores food for a short time and mixes food with acidic digestive juices to form chyme *ans*Stomach First part of the small intestine where semi liquid food is mixed with pancreatic juice and bile *ans*Small intestine: Duodenum Second part of the small intestine where digested food is absorbed into the blood *ans*Small intestine: Ileum Produces pancreatic juice which contains enzymes -Poured into the small intestine through the pancreatic duct -Neutralises acidic chyme *ans*Pancreas Produces bile; important in assimilation -Emulsifies fat -Neutralizes acidic chyme *ans*Liver Where bile is stored before it enters the small intestine *ans*Gall bladder Absorbs water, vitamins and minerals from gut content *ans*Large intestine: Colon Where feaces is stored before being expelled at a convenient time *ans*Large intestine: Rectum The breakdown of large insoluble food molecules into small, water soluble molecules using chemical and mechanical processes -Food cannot be digested unless molecules are small and soluble *ans*Digestion The maintenance of glucose in the body. -The hormone glucagon causes liver to convert glycogen to glucose if the energy is needed -The hormone insulin causes glucose to convert to glycogen if blood sugar levels are to high *ans*Glucoregulation (negative feedback for glucose content) Produced in the liver -Gives fat a larger surface area for lipase to work on *ans*Bile: Funciton -Salivary glands -Pancreas *ans*Where is amylase secreted -Stomach *ans*Where is protease secreted -Pancreas *ans*Where is lipase secreted The movement of digested food molecules through the wall of the small intestines into the blood -Nutrients that are absorbed through the wall of the small intestine (villi) gets absorbed by the capillary network which comes together to form the hepatic portal vein *ans*Absorption in the small intestine Fingerlike structures which the ileum is folded into -Higher surface area for absorption -Where digested food molecules enter the capillaries -Each villi has a blood supply -Each villi is made up of even smaller micro-villi *ans*Villi Capillary which absorbs fat *ans*Lacteal Fat is stored in the body as an energy storage substance -Fat can be broken down into glycerol (which can be converted to glucose and used as a source of energy) and fatty acids *ans*The role of fat in the body Transports water and dissolved minerals from the root up to all the other parts of the plant -Xylem tubes are made up from dead cells *ans*Xylem: Function Transports food nutrients such as glucose from the leaves to other parts of the plant -Consist of columns of living cells *ans*Phloem: Function 1- Water and inorganic ions move from the soil to the root hair cell down a concentration gradient (osmosis) 2- Mineral ions and water travel to the xylem tube 3- Xylem vessel transports water and mineral ions up the xylem tube from the root to the stem and leaves 4-Water and mineral ions leave the xylem and is absorbed by the cells in the leaves *ans*Describe how water and mineral ions travels throughout the plant -Put celery stalk in a water with food cloring -Leave for a while -Celery will take on the same colour as the food colouring *ans*Investigating water movement in plants The evaporation of water at the surfaces of the mesophyll cells followed by the loss of water vapour from the plant leaves through the stomata *ans*Transpiration The higher the temperature the faster the rate of transpiration -More kinetic energy, evaporation happens faster *ans*Temperatures effect on transpiration The higher the light intensity the faster the rate of transpiration -Stomata will open to allow more carbon dioxide in for photosynthesis; higher chance for water molecule to escape through the stomata via transpiration *ans*Lights effect on transpiration The more humid the surroundings are, the slower the rate of transpiration -The more water vapour there is in the surroundings, the lower the concentration gradient there is for water to transpire to *ans*Humidities effect on transpiration -Water in the mesophyll cells form a thin layer on their surfaces -Water will evaporate into the airspaces in the spongy mesophyll causing a high concentration of water vapour in the air space -Water molecules will then travel our of the leaf through the stomata by diffusion *ans*Describe the process of transpiration A system of tubes with a pump and valves to ensure one way flow *ans*Circulatory system Devices that control the direction of blood flow in the body -They close and open to ensure one way flow of blood *ans*Valves The body contains a double circulatory system -One system pumps blood to the lungs where it becomes oxygenated -Oxygenated blood enters the second circuit where it is pumped to the rest of the body (When blood is transported from the heart to the lungs, the pressure it travels at is relatively smaller than the second circuit, where blood is transported from the heart to the rest of the body) *ans*Double circulation Vena cava right atrium tricuspid valve right ventricle pulmonary valve pulmonary artery lungs pulmonary veins left atrium bicuspid Left ventricle aortic valve aorta body *ans*order of blood flow in the heart