bio paper one

• what do both animal and plant cells have in common

  • nucleus (dna) cell membrane controls what enters and leaves mitchondria where respiration takes place cytoplasm ribosome protein synthesis
• stem cells


  can specialise to perform specific functions and are found in animal embryos and plant meristems some are made in bone marrow but can only specialise into blood
• diffusion


  movement of particles from a high to low concentration, this movement is passive as it requires no energy; the rate can be increased by change in temperature , surface area and difference in concentration.
• osmosis


  the movement of water molecules from a solution with a high concentration of water molecules to low through a semi permeable membrane.
• osmosis practical


  weigh and place identical cylinders from same vegetable in sugar solutions of varying concentrations then set time and remove water to reweigh; calculate change in mass.
• active transport


  the movement of particles through a membrane this requires energy
• Digestive system


  1. Teeth breakdown food mechanically (saliva contains amylase)

  2. Stomach breaks down food chemically as it contains hydrochloric acid and enzymes

  3. Liver produces bile which is stored in the gall bladder before going to the small intestines

  4. Pancreas secretes amylase which breaks down starch into glucose in the small intestine

  5. Nutrients like glucose is absorbed into the bloodstream by villi in the small intestine

  6. Water is absorbed into the bloodstream in the large intestine
• enzymes

  they proteins that act as biological catalysts which are specific as they only break down substrates that fit into their active site. the activity increases with temperature until the enzyme denatures
• enzymes practical


  1.mix amylase until starch and start timer 2.remove a few drops from mixture every 10 seconds and add to iodine 3.record the time taken for no starch to be detected (will remain orange) 4.repeate at different temperature or ph
• food tests

  1. STARCH; iodine turns from orange to black 2.SUGARS; benedict solution turns from blue to orange 3.PROTIEN; biuret reagent turns from blue to purple 4.LIPIDS; turn cold ethanol cloudy
• the heart 


  vena cava; deoxygenated blood enters and the valve prevents backflow of deoxygenated blood from re entering the body the heart muscles contract and it goes through the pulmonary artery to the lungs to be oxygenated the comes back to the heart through the pulmonary vein the through the left atrium and ventricle and out the aorta
• plant structure

  1.flower; reproductive organs 2.meristem; stem cell production 3.xylem; carries water and dissolved mineral ions upwards, transpiration rate increased with increased air movement or temperature and decreased humidity 4.roots; water enters through osmosis, mineral ions by active transport
• defence and immune system


  lymphocytes produce antitoxins to neutralise toxins made by pathogens, Vaccines can develop immunity by imitating an infection and stimulating an immune response.
• drug development

  • antibiotics only kill bacteria and are difficult to make target specific bacteria so they dont damage 'good' bacteria, the whole course must be take to kill all bacteria or more resistant bacteria will multiply
• natural drugs 


  1.asprin is a pain killer made from trees 2.penicillin came from mould and is the first antibiotic
• synthetic drugs

  they arec expensive to develop and are put through trials to test for efficacy , toxicity and dose. they are tested on cells animals and humans 1. blind trials are two groups who are given drugs or placebo 2.double blind trials is when both the doctor and participant dont know which drug is being tested to remove bias.
• photosynthesis practical 


  cut pondweed stem and put it in inverted measuring cylinder filled with water with sodium hydrogencarbonate added to the water to supply carbon dioxide and measure the distance from light source. repeat at different distances from light.
• aerobic respiration

  glucose + oxygen → carbon dioxide + water C6H12O6 + 6O2 → 6CO2 + 6H2O exercise; heart and breathing rate increase to increase blood flow to supply more oxygen and glucose to enable muscle to contract
• anaerobic respiration

  C6H12O6 -> 2C3H6O3(Glucose -> Lactic acid). occurs during intense exercise; oxygen debt. lactic acid is broken by the liver into glucose using oxygen
• plant cell

  chloroplast where photosynthesis takes place and chlorophyll cell wall (cellulose)
• plant cell

  plasmid (loop of dna) ribosome cytoplasm mitchondria