1 markWhich of the following best describes what an enzyme is?
A catalyst that speeds up reactions in cells, being used up in the process
A protein that speeds up reactions in cells, being used up in the process
A carbohydrate that functions as a biological catalyst
A protein that functions as a biological catalyst
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1 markWhat is a feature of all catalysts?
They are made from protein
They are not changed by the reaction
They are broken down in the reaction
They are altered by the rate of the reaction
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1 markWhat can be said to be true of all enzymes?
| their optimum pH is 7 | they are made from amino acids | they move about randomly in a fluid | |
| A | X | X | X |
| B | X | ✓ | ✓ |
| C | ✓ | X | ✓ |
| D | ✓ | ✓ | X |
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1 markWhat is the name for the group of compounds that ensures metabolic reactions take place in living organisms at a speed necessary to sustain life?
Proteins
Enzymes
Catalysts
Hormones
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What is the correct description of enzymes?
biological catalysts made of lipids
biological catalysts made of proteins
catalysts that slow down chemical reactions and are changed by the reaction
catalysts that speed up chemical reactions and are changed by the reaction
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Enzyme action can be explained by the lock and key hypothesis.
Which row is correct for the active site and the substrate?
| active site is on the enzyme |
active site is on the substrate |
substrate is the lock |
substrate is the key |
|
| A | ✓ | x | ✓ | x |
| B | ✓ | x | x | ✓ |
| C | x | ✓ | ✓ | x |
| D | x | ✓ | x | ✓ |
Key:
✓ = Yes
x = no
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1 markThe image below represents a chemical reaction.
Which of the following best represents the enzyme responsible for catalysing this reaction?
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1 markThe action of an enzyme in a chemical reaction is outlined in the diagram below.
Which row of the table below is correct?
| product | enzyme | enzyme-substrate complex | |
| A | E | H | G |
| B | E | G | F |
| C | H | G | F |
| D | H | F | G |
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1 markThe diagrams below show an amylase enzyme catalysing the breakdown of part of a starch molecule into smaller molecules of maltose.
Which diagram has three correct labels?
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