What name is given to reactions that occur isnside the human body?
Metabolic reactions
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What is an enzyme?
A biological catalyst, made from proteins, that speed up the rate of specific chemical reactions to produce specific products. They remain unchanged during the reactions
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What is the activation energy?
The minimum energy required to start a reaction
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What enzyme breaks down hydrogen peroxide?
Catalase
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What are the products of the breakdown of hydrogen peroxide?
Water and oxygen
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Write the equation for the breakdown of hydrogen peroxide with catalse:
H2O2 --> 2H2O + O2
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What does the enzyme ribonuclease do?
Hydrolyses RNA (ribonucleic acid)
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What is the active site?
A tertiary structure that has formed on the surface of the enzyme that has a specific shape that compliments specific substartes.
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Describe how an enzyme breaks down the substrate:
The enzyme catalyses the substrate when the substrate binds with the active site to form an enzyme-substrare complex. The complex then breaks down to form producys. The enzyme remains unchanged.
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Describe the induced fit model:
The substrate has a complementay shape to the active site, they're not identical. As the substrate binds the active site changes shape and moulds around the substrate.
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Describe the lock and key model:
The substrate (key) has the exact same shape as the active site (lock). The enzyme is only able to bind with specifc substrates to form the products
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What evidence is there for the induced fit model?
Hexokinase catalyses glucose and ATP. X-ray diffraction was used to monitor the 3D shape of the active site during the reaction. It was seen that the active site changed shape
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What is denaturation?
A permanent change to the shape of the active site caused by hydrogen bonds and ionic bonds breaking that maintain its tertiary structure .
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How does an increase in temperature cause denaturation?
Kinetic energy is increased and the enzyme molecules vibrate more vigorously breaking the ionic and hydrogen bonds causing the tertiary structure to change shape
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How can a change is pH cause denaturation?
Changing pH changes the concentration of hydrogen (acidic) ions and hydroxyl (alkaline) ions. This alters the charges on the amino acids on the active site preventing substances from binding
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What is a competitive inhibitor?
Molecules with a very similar shape to the substrate that compete with the substrate for the active site. They bind with the active site blocking the substrate from forming the enzyme-substrate complex
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How do non-competitive inhibitors work?
They bind to the enzyme (elsewhere of the active site) causing the active site to change shape preventing an enzyme-substrate complex from being formed
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What can increase the chance of enzyme-substrate collisions?
Increase in temperature and increase in substrate concentration
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How does increasing temperature to optimum increase the rate of an ezyme-controlled reaction?
The increase in temperature causes the enzyme to gain kinetic energy causing it to move faster. This increase the chance of enzyme-substrate collisions.
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Other cards in this set
Card 2
Front
What is an enzyme?
Back
A biological catalyst, made from proteins, that speed up the rate of specific chemical reactions to produce specific products. They remain unchanged during the reactions
Card 3
Front
What is the activation energy?
Back
Card 4
Front
What enzyme breaks down hydrogen peroxide?
Back
Card 5
Front
What are the products of the breakdown of hydrogen peroxide?
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