Questão 1
Questão
The main reason why rate of enzyme action increases with temperature initially is...
Responda
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The kinetic energy of enzymes and substrates increases
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Time passing, allowing more collisions to occur
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The enzymes become denatured
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More substrate is produced, therefore the enzymes become saturated
Questão 2
Questão
The level of a condition at which enzymes work best is called the [blank_start]optimum[blank_end] temperature/pH/etc.
Questão 3
Questão
Why do enzymes work less effectively in extreme pH, or in very high temperatures?
Responda
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pH far from optimum affects bond interactions in the enzyme.
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High temperatures provide enough kinetic energy to break bonds in the enzyme protein structure.
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Enzymes become denatured.
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Substrates have very high kinetic energy and collide too quickly with enzymes.
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Enzyme tertiary structure changes.
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The induced-fit hypothesis says that the active site tertiary structure remains constant when 'not occupied'.
Questão 4
Questão
The optimum temperature for enzymes in the human body is 37 degrees C.
Questão 5
Questão
Rate of reaction is proportional to..
Responda
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The number of ESCs formed per second.
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The number of enzyme proteins that become denatured by second.
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The optimum temperature for a specific enzyme.
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The solubility of ESCs formed in the reaction process.
Questão 6
Questão
There is a [blank_start]positive[blank_end] correlation between substrate concentration and initial rate of reaction. However, past a point, the graph [blank_start]plateaus[blank_end]. This is because of [blank_start]a limiting factor[blank_end], which is the [blank_start]enzyme concentration[blank_end]. At this point and beyond, the enzymes are said to be [blank_start]saturated[blank_end].
Questão 7
Questão
Cells create one set of enzymes that last for the duration of the cell's life.
Questão 8
Questão
Inhibitors that [blank_start]block[blank_end] the [blank_start]active site[blank_end] of enzymes are [blank_start]competitive[blank_end], whereas inhibitors that [blank_start]change[blank_end] the [blank_start]shape[blank_end] of enzymes are [blank_start]non-competitive[blank_end].
Responda
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block
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acidify
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expose
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signal
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active site
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tertiary structure
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synthesis
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degradation
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competitive
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non-competitive
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change
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block
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expose
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precipitate
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shape
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primary structure
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kinetic energy
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non-competitive
-
competitive
Questão 9
Questão
Label the enzyme inhibition diagram.
Responda
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Normal enzyme activity
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Competitive inhibitor
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Non-competitive inhibitor
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Normal enzyme activity
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Competitive inhibitor
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Non-competitive inhibitor
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Normal enzyme activity
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Competitive inhibitor
-
Non-competitive inhibitor
Questão 10
Questão
Which of the following statements are true about end product inhibition? Select all that apply.
Responda
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Most metabolic reactions consist of one step.
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An end product inhibits an enzyme that is responsible for its synthesis.
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One product of the metabolic pathway inhibits the overall pathway.
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The end product accumulates.
Questão 11
Questão
[blank_start]Potassium cyanide[blank_end] is an inhibitor that is also a metabolic poison. In the body, it forms [blank_start]hydrogen cyanide[blank_end]. The [blank_start]cyanide[blank_end] ions bind [blank_start]irreversibly[blank_end] to [blank_start]mitochondria[blank_end] and prevent normal [blank_start]aerobic respiration[blank_end].
Snake venom contains [blank_start]acetylcholinesterase[blank_end], which prevents the breakdown of [blank_start]acetylcholine[blank_end], thereby preventing muscle relaxation.
Various therapeutic drugs are available that work by inhibiting enzymes such as [blank_start]ACE[blank_end], [blank_start]proteases[blank_end], and [blank_start]ATPase[blank_end].