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95 Cards in this Set
- Front
- Back
What does the nucleus contain? |
DNA which contains the instructions for making proteins |
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What is the cytoplasm? |
gel-like substance |
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What is made in the cytoplasm? |
proteins like enzymes are made in it |
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What reactions happen in the cytoplasm? |
some enzyme-controlled reactions (like the reactions of anaerobic respiration) |
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What does the cell membrane do? |
holds the cell together |
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What does the cell membrane control? |
what goes in and out of the cell lets gases and water pass through freely while acting as a barrier to other chemicals |
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What is found in the mitochondria? |
the enzymes needed for the reactions of aerobic respiration are found |
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What takes place in the mitochondria? |
where the reactions take place |
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Name the three extra things that a typical plant cell has that a typical animal cell doesn't have. |
rigid cell wall, vacuole, chloroplasts |
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What is the cell wall made of and what is its function? |
made of cellulose supports the cell and strengthens it |
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What does the vacuole contain? |
cell sap, a weak solution of sugar and salts |
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What reaction take place in the chloroplasts? |
photosynthesis |
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What 2 things do chloroplasts contain? |
a green substance called chlorophyll the enzymes needed for photosynthesis |
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What 5 things do yeast cells contain? |
cell membrane cytoplasm nucleus mitochondria cell wall |
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What is yeast used to make? |
bread and wine |
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What four things do bacteria cells contain? |
cell membrane cell wall cytoplasm circular DNA molecule |
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Do bacteria cells still respire aerobically? |
yes |
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What are enzymes? |
proteins that speed up chemical reactions |
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Where are instructions for making enzymes and other proteins found? |
in a cell's genes |
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What two things do chemical reactions usually involve? |
things either being split apart or joined together |
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What is a substrate? |
a molecule that is changed in a reaction |
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What does every enzyme have where the substrate joins on to the enzyme? |
active site |
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How many different substrates can an enzyme speed up the reaction of? |
one |
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Why do enzymes usually only speed up one reaction? |
for an enzyme to work, a substrate has to be the correct shape to fit into the active site |
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What model shows the substrate fitting into the enzyme? |
the lock and key model |
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Does the substrate or enzyme change after the reaction? |
the substrate changes, the enzyme does not |
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Can enzymes die? |
no, they were never alive in the first place |
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What is something that speeds up a reaction called? |
a catalyst |
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What 2 things can enzymes do to substrates? |
build things up or break things down |
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What two environmental factors affect the way enzymes work? |
pH and temperature |
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Describe the relationship between increasing temperature and the rate of an enzyme-controlled reaction. |
a higher temperature increases the rate at first if it gets too hot, the enzyme is denatured |
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What happens when an enzyme is denatured? |
the bonds holding the enzyme together begin to break, changing the shape of the active site, so the substrate will no longer fit and the enzyme won't work any more |
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Describe the relationship between pH and the rate of an enzyme-controlled reaction. |
all enzymes have an optimum pHthat they work at if the pH is too low or too high it denatures the enzyme |
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Define respiration. |
a series of chemical reactions that release energy by breaking down large food molecules that happens in every living cell |
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What three chemical reactions that occur in cells does respiration power? |
movement active transport synthesis of large molecules |
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How is energy used in movement? |
it is used to make muscles contract |
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What is active transport? |
a process that uses energy to move some substances in and out of cells |
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How are large molecules made? |
by joining smaller molecules together |
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What is joined together to make things like starch and cellulose? |
glucose |
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What are glucose and nitrogen joined together to make? |
amino acids |
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What do amino acids join together to make? |
proteins |
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What are the two types of respiration? |
aerobic and anaerobic |
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Which type of respiration releases more energy per glucose molecule? |
aerobic respiration |
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In what types of cells does aerobic respiration take place? |
animal, plant, and some microorganisms |
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What is the word equation for aerobic respiration? |
glucose + oxygen -> carbon dioxide + water (+ energy released) |
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What is the symbol equation for aerobic respiration? |
C6H12O6 + 6O2 -> 6CO2 + 6H2O (+ energy released) |
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Where does anaerobic respiration take place? |
animal, plant, and some microorganisms |
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In what circumstances does anaerobic respiration occur? |
when there's very little or no oxygen |
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Give a situation in which human cells respire anaerobically. |
during vigorous exercise the body can't supply enough oxygen to muscle cells for aerobic respiration |
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Give a situation in which plant cells respire anaerobically. |
roots in waterlogged soil |
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Give a situation in which bacterial cells respire anaerobically. |
when bacteria gets under your skin through cuts only bacteria that can respire anaerobically survive under the skin |
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What is the word equation for anaerobic respiration in animal cells and some bacteria? |
glucose -> lactic acid (+ energy released) |
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What is the word equation for anaerobic respiration in plant cells and some microorganisms? |
glucose -> ethanol + carbon dioxide (+ energy released) |
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Give an example of a microorganism which respires anaerobically. |
yeast |
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What is fermentation? |
when microorganisms break down sugars into other products as they respire anaerobically |
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List 3 things humans use fermentation to make. |
biogas bread alcohol |
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What is biogas made of? |
mainly methane and carbon dioxide |
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How does yeast cause bread to rise? |
the release of carbon dioxide |
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Define photosynthesis. |
photosynthesis is a series of chemical reactions that uses energy from sunlight to produce food |
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What is the 'food' product of photosynthesis? |
glucose |
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Where does photosynthesis happen? |
the cells in green parts of plants some microorganisms |
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What substance is required for photosynthesis? |
chlorophyll |
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What is chlorophyll? |
a green substance which absorbs sunlight and allows the energy to be used to convert carbon dioxide and water into glucose |
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What is the waste product of photosynthesis? |
oxygen |
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Which part of the food chain do organisms that photosynthesise form? |
the start of the food chain |
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What is the word equation for photosynthesis? |
carbon dioxide + water -> glucose + oxygen |
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What is the symbol equation for photosynthesis? |
6CO2 + 6H2O -> C6H12O6 + 6O2 |
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What three things do plants use glucose for? |
respiration to make chemicals for growth glucose is stored as starch |
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What is glucose converted into to make cell walls? |
cellulose |
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What is glucose combined with to make amino acids? |
nitrogen |
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What important substance in photosynthesis is glucose used to help make? |
chlorophyll |
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When is stored starch used? |
at times when the rate of photosynthesis is slower, like in the winter |
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What are the three factors that can affect the rate of photosynthesis? |
amount of light amount of CO2 temperature |
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What is a limiting factor in terms of photosynthesis? |
something that stops photosynthesis from happening any faster |
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What decides which factor that affects photosynthesis becomes the limiting factor? |
the environmental conditions |
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When is light the limiting factor? |
at night |
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When is temperature the limiting factor? |
at winter |
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When is the amount of CO2 the limiting factor? |
if it's warm enough and bright enough |
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Describe the graph for rate of photosynthesis against light intensity. |
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Describe the graph for rate of photosynthesis against % level of CO2. |
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Describe the graph for the rate of photosynthesis against temperature. |
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At what temperature are enzymes denatured? |
45 degrees |
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What is a transect used for? |
a way of investigating how something changes across an area |
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How do you set up a transect? |
run a tape measure between two fixed points |
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How do you collect data from a transect? |
start at one end of the transect and collect data as you move along the transect until the end |
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What is a light meter used for? |
measure the level of light a sensor that accurately measures light level |
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What is a quadrat? |
square frame divided into a grid of 100 smaller squares |
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What is a quadrat used for? |
makes data collection quicker and easier estimate percentage cover |
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What is an identification key? |
a series of questions that can be used to figure out what a plant is |
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Define diffusion. |
diffusion is the passive overall movement of particles from a region of their higher concentration to a region of their lower concentration |
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Give an example of diffusion in plants. |
when plants photosynthesise they use up CO2 from the atmosphere and produce O2 these gases pass in and out of plant leaves by diffusion |
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Define osmosis. |
osmosis is the overall movement of water from a dilute to a more concentrated solution through a partially permeable membrane |
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What is a partially permeable membrane? |
one that allows certain substances to diffuse through it |
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How do plants take in water? |
through osmosis |
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Define active transport. |
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 |