Biology
- Created by: AOconnor
- Created on: 14-05-18 17:21
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- Biology
- Prokaryotes
- Bacterial cells
- Simpler structures than eukaryotes
- Role of mitochondria and chloroplasts taken over by cytoplasm
- Flagella are tail like structures that help the bacterium move by rotating
- Plasmids are loops of DNA that can be transferred from one cell to another
- Allow bacterial cells to move genes from one cell to another
- Can be used in genetic engineering
- Can replicate independently of chromosomal DNA
- Allow bacterial cells to move genes from one cell to another
- Chromosomal DNA is found as one long, looped chromosome in cytoplasm since there is no nucleus
- Cell wall provides structural support but isn't made of cellulose
- Bacterial cells
- Eukaryotes
- Plant Cell
- Cell wall provides structural support
- Made of cellulose which can be made using glucose from photosynthesis
- Vacuole stores cell sap, which supports the cell
- Chloroplasts contain pigment called chlorophyll which absorbs sunlight
- Cell wall provides structural support
- Animal cell
- Cell membrane controls what passes in/out of cell
- Nucleus stores genetic material controls activity of cell
- Cytoplasm is the site of many chemical reactions
- Mitochondria is site of respiration
- Ribosomes is site of protein synthesis
- Plant Cell
- Transport
- Osmosis
- Movement of water down concentration gradient (high to low) across partially permeable membrane
- Practical
- Potatoes used to measure effect of sugar solutions on plants
- Cut cylinders of potato and measure mass
- Place cylinders in different sugar solutions
- After 30 mins remove cylinders and measure mass
- Place cylinders in different sugar solutions
- Variables
- Control: temperature, length of time cylinders left in solution and volume of solution
- Independent: concentration of sugar solutions
- Dependent: Change in mass of potatoes
- Practical
- Movement of water down concentration gradient (high to low) across partially permeable membrane
- Active transport
- Movement of substance against concentration gradient (low to high)
- Requires energy from respiration
- Movement of substance against concentration gradient (low to high)
- Diffusion
- Net movement of particles down a concentration gradient (high to low) until evenly spread out
- Factors affecting diffusion
- Concentration gradient
- Temperature
- Surface area of membrane
- Factors affecting diffusion
- Net movement of particles down a concentration gradient (high to low) until evenly spread out
- Osmosis
- Digestion
- Enzymes
- Catalyse breakdown of large insoluble food molecules into smaller soluble molecules
- Properties
- Large proteins
- Have active site
- Catalyse specific reaction
- Work best at optimum pH and temperature
- Types
- Amylase
- Breaks down starch into sugar (maltose)
- Produced in salivary gland and pancreas
- Protease
- Breaks down protein into amino acids
- Produced in stomach, pancreas and small intestine
- Lipase
- Breaks down fats into fatty acids and glycerol
- Produced in small intestine and pancreas
- Amylase
- Tests for substances
- Glucose
- Benedict's reagents added to food molecule with water and heated
- If present goes red
- Benedict's reagents added to food molecule with water and heated
- Protein
- Biuret reagents added
- If present goes purple
- Biuret reagents added
- Lipids
- Iodine solution added
- If present goes black/blue
- Iodine solution added
- Glucose
- Properties
- Catalyse breakdown of large insoluble food molecules into smaller soluble molecules
- Bile
- Produced in liver and stored in gall bladder
- Alkaline so it neutralises HCL in stomach
- Optimises conditions for lipase to breakdown fats and increases rate of breakdown
- Emulsifies fat into small droplets (increasing surface area for enzymes to work on
- Optimises conditions for lipase to breakdown fats and increases rate of breakdown
- Enzymes
- Prokaryotes
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