ENZYMES Flashcards

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1
Q

Enzymes catalyze all the chemical reactions required to ________, ________, and _______ life

A

Build, sustain, reproduce

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2
Q

An enzyme is a _______

A

Catalyst

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3
Q

An enzyme is a catalyst that-

A

-Accelerates the rate of one or more chemical reactions
-Is not permanently changed or consumed by the reaction it catalyzes
-Is a protein or RNA molecule (ribozyme)

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4
Q

How many chemical reactions occur in a eukaryotic cell?

A

~1 million

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5
Q

Enzymes enable each chemical reaction to occur at the proper…

A

Location, time, and generate correct product concentration

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6
Q

Enzymes significantly ______ the rates of chemical reactions enabling life to occur

A

Accelerate

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7
Q

The average enzyme performs how many reactions per second?

A

~1,000

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8
Q

Enzymes lower the ______ _______ required for a chemical reaction to occur

A

Activation energy

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9
Q

Most enzymes are…

A

Proteins
RNA molecules called ribozymes

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10
Q

What is the active site?

A

Part of the enzyme that catalyzes a specific chemical reaction

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11
Q

What “fits” in the active site?

A

The substrate

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12
Q

Activation energy is the amount of energy….

A

A substrate must absorb to initiate a chemical reaction

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13
Q

Activation energy is required for a substrate to enter the _________ ________

A

Transition state

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14
Q

What is the transition state?

A

An intermediate, energized, unstable phase ready to react to form product

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15
Q

Cells use a sequence of enzymes called a _________ pathway to synthesize many types of product molecules

A

Biochemical

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16
Q

What is a biochemical pathway and its purpose?

A

Sequence of enzymes; synthesizes many types of product molecules

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17
Q

When the cell has the necessary concentration of the product, the product will _______ an enzyme in the pathway

A

Inhibit

18
Q

The _______ of enzyme #1 becomes the ________ for enzyme #2

A

Product; substrate

19
Q

What enables cells to maintain the proper concentration of each product?

A

Rapid and reversible enzyme regulation

20
Q

What is negative feedback regulation?

A

Controls the activity of many enzymes to maintain proper product levels

21
Q

When does negative feedback occur?

A

When the restoration of normal conditions stops the corrective process

22
Q

Two types of negative feedback regulation

A

-Competitive inhibition
-Noncompetitive inhibition

23
Q

Competitive inhibition

A

Competitive inhibitor interferes with active site of enzyme so substrate cannot bind
The inhibitor is in similar shape to the substrate
Inhibitor binds to active site, prevents the substrate from binding

24
Q

Noncompetitive inhibition

A

Allosteric inhibitor changes shape of enzyme so it cannot bind to substrate
Causes the enzyme to change shape
Closes the active site, substrate cannot bind to active site

25
Q

Many pharmaceuticals are…

A

Enzyme inhibitors

26
Q

Allosteric meaning

A

Shape, structural change

27
Q

________ regulation is a type of negative feedback regulation that….?

A

Allosteric; controls many enzymes and proteins

28
Q

Allosteric regulators can be…

A

Off switches or on switches

29
Q

Allosteric regulation process

A

The regulator binds to a specific part of a protein, which consequently changes the activity of another part of the protein

30
Q

_________ inhibition is a type of allosteric regulation

A

Noncompetitive

31
Q

Example of pharmaceutical allosteric regulator

A

Anti histamines
Activate or inhibit proteins

32
Q

Two enzymes that regulate enzyme activity:

A

-Protein kinases
-Protein phosphatases
-Regulate ~40% of all cell activity

33
Q

Kinases:

A

Add a phosphate group (phosphorylation)

34
Q

Phosphatases:

A

Remove a phosphate group (dephosphorylation)

35
Q

What conditions determine the enzyme’s function?

A

-Temperature
-pH
-Salt concentration
Cellular or extracellular environment

36
Q

Most human enzymes perform optimally at what temperature?

A

37-41 C
Average core temp of human body is 37 C (98.6)

37
Q

Many enzymes require _______?

A

Cofactors (enzyme helpers)
Cofactors bind to the active site to activate the enzyme

38
Q

Two types of cofactors?

A

Mineral and vitamin

39
Q

Mineral cofactors:

A

Calcium, cobalt, copper, iron, magnesium, manganese, zinc

40
Q

Vitamin cofactors:

A

B vitamins, Vitamin C, Vitamin K

41
Q

Without the cofactor….

A

The enzyme can’t lock the reacting substance (substrate) into its active site, so the reaction can’t take place