5: Enzymes Flashcards

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1
Q

Catalyst definition

A

substance that increases the rate of a chemical reaction and is not changed by the reaction

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2
Q

Enzyme definition

A

proteins that function as biological catalysts

speed up the rate of metabolic reactions

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3
Q

Why are enzymes important in all living organisms?

A

speed up the rate of metabolic reactions
without - would take too long to occur

(so we will probably die :D)

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4
Q

Enzyme action

A

Lock and key hypothesis

  1. Substrate that fits the specific active site of enzyme binds to create an ENZYME-SUBSTRATE COMPLEX
  2. reaction occurs (catalysed by the enzyme)
  3. products released
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5
Q

Enzyme specificity

A

Each enzyme is complementary to only 1 type of substrate

has an active site - sequence of amino acids with specific shape that fit specific substrate

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6
Q

Factors that affect the rate of an enzyme-controlled reaction (4)

A
  • temperature
  • pH
  • substrate concentration
  • enzyme concentration
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7
Q

effect of temp on enzymes

above opt temp?

A

↑ temp = ↑ rate
until opt temp, particles have more KE - move faster = more successful collisions occur - more enzyme-substrate complexes formed

above optimum temperature:
enzymes DENATURE
active site distorted - heat breaks bonds that hold enzyme together
no longer fits the substrate- no enzyme-substrate complex can be formed (no reaction)

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8
Q

effect of pH on enzymes

above opt pH?

A

opt pH = highest rate

pH is too ↑ or ↓ = rate ↓
enzymes DENATURE - active site distorted, no longer fits the substrate

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