B4 REVISION MINDMAP
a revision mindmap i created for myself, helped me understand everything, hope your mind will absorb it too!
- Created by: Habz~
- Created on: 11-01-13 19:43
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- B4 - mindmap
- Cells
- Animal cells contain nucleus, cytoplasm (where proteins like enzymes are made), cell membrane (controls what goes in and out) and mitochondria ( where enzymes needed for aerobic respiration are found)
- Plants cells have all of the above plus extra. they also have cell wall, vacoule and chloroplasts ( where reactions for photosynthesis takes place.
- yeast cells have a nucleus, cell membrane, cytoplasm, mitochondria and a cell wall
- bacteria cells have a circular DNA molecule instead of a nucleus, cell membrane, cytoplasm and cell wall
- Enzymes
- Enzymes are proteins that speed up chemical reactions.
- a substrate is a molecule that has been changed in a chemical reaction.
- the lock and key model: every enzyme molecule has an active site, enzymes usually only speed up one reaction because for an enzyme to work, a substrate has to be the correct shape to fit into the active site. when it does fit, there is a chemical reaction and products are formed.
- enzymes need to be at a specific temperature to work at their optimum. a higher temperature changes the rate of reaction. if it gets too hot some of the bonds holding the enzyme together break and so changes the shape of the enzymes active site. the substrate wont fit and the enzyme is denatured.
- Respiration
- Respiration is a series of chemical reactions that release energy by breaking down food molecules.
- the enrergy released by respiration is used in different things. these include movement, active transport and synthesis of large molecules.
- Active Transport: This process uses energy to move some substances in and out of cells.
- Movement: Energy is needed to make muscles contract.
- Synthesis of large molecules: polymers are made by joining smaller molecules together, this requires energy.
- Aerobic respiration
- Aerobic respiration releases more enegy per glucose molecule than anaerobic respiration.
- aerobic respiration takes place in animal and plant cells and in some microorganisms
- equation: Glucose + Oxygen = carbon dioxide + water
- symbol equation: C6H12O6 + 6O2 ? 6CO2 + 6H2O
- Anaerobic respiration
- anaerobic respiration takes place in animal and plant cells and some microorganisms when there is very little or no oxygen.
- human cells: when you do very vigorous exercise your body cannot supply enough oxygen to your muscle cells for aerobic respiration so they start to respire anaerobically.
- plant cells: if the soil a plant is growing in becomes waterlogged, there will be no oxygen available for the roots so the root cells will have to respire anaerobically,
- bacterial cells: when bacteria cells get under your skin where there is very little oxygen, they respire anaerobically to survive.
- the equation of this type of respiration in animal cells and some bacteria cells produces lactic acid. Glucose = lactic acid
- in plant cells and some microorganisms like yeast, anaerobic respiration produces carbon dioxide and ethanol
- Fermentation is when microrganisms break down sugars into other products as they respire anaerobically
- Photosynthesis
- phtosynthesisis a series of chemical reactions that uses energy from sunlight to produce food.
- potosynthesis happens in the cells in green parts of plant
- chlorophyll is need for photosynthesis to happen. it is a green substance which absorbs sunlight and allows the energy to be used to convert CO2 and water into glucose.
- carbon dioxide + water = glucose + oxygen
- glucose is used for respiration, it is used to make chemicals for growth and is stored as starch.
- factors affecting the rate of photosynthesis are the amount of light, amount of CO2 and temperature
- investigating photosynthesis
- transects are a way of investigating how something changes across an area. to set up a transect you run a tape measure between two fixed points.
- lights meters: this measures the level of light, its a sensor that accurately measures light level.
- quadrat: this is a square frame divided into a grid of 100 smaller squares.
- identification key: this is a series of questions that you can use to figure out what a plant is.
- Diffusion, Osmosis and Active Transport
- Diffusion is the passive overall movement of particles from a region of their higher concentration to a region of their lower concentration
- an example of diffusion is when carbon dioxide and oxygen pass in and out of plants, they do this by diffusion.
- osmosis is the overall movement of water from a dilute to a more concentrate solution though a partially permeable membrane.
- active transport is the overall movement of chemicals across a cell membrane from a region of lower concentration to a region of higher concentration using energy released by respiration.
- Cells
- Respiration is a series of chemical reactions that release energy by breaking down food molecules.
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