B M 4 : Enzyme Action Flashcards Preview

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Flashcards in B M 4 : Enzyme Action Deck (25):
1

What are enzymes and what do they do?

Biological catalysts
- speed up chemical reactions by acting as biological catalysts

2

At what levels do enzymes catalyse metabolic reacts?

Cellular level (respiration)
And for the organism as a whole (digestion on mammals)

3

At can enzymes affect? Give an example

The structures in an organism
- they’re Involved in the production of collagen, important protein in the connective tissue of mammals

4

Where can enzyme action take place?

-intercellular (within cells)
OR
-extracellular (outside cells)

5

What are enzymes classes as?

Proteins

6

Which part of the enzyme does the substrate molecule bind to?

Active wire, which has a specific shape

7

Why are enzymes highly specific?

Due to their tertiary structure

8

What do enzymes lower?

The activation energy of a reaction

9

What’s activation energy?
And what’s it often provided as?

The amount of energy that needs to be supplied to the chemicals before the reaction will start
-heat

10

What’s it form when a substrate fits into an enzymes active site?

An enzyme-substrate complex

11

What causes enzymes to lower the activation energy?

The formation of an enzyme-substrate complex

12

One reason Why an enzyme-substrate complex lowers the activation energy?

- if two substrate molecules need to be joined, being attached to an enzyme brings them closer together
- reducing any repulsion between the molecules so they can bond easily

13

Another reason why an enzyme-substrate complex lowers the activation energy

If enzyme catalysts a breakdown reaction, putting into the active site puts strain on bonds in the substrate
- so substrate molecule breaks up more easily

14

Lock and key model?

-substrate fits into enzymes active site
- enzyme-substrate complex formed
- substrate broken down products released after reaction
- enzyme is unchanged after reaction

15

Does the lock and key model give the full story?

No

16

What does new evidence show?

The enzyme-substrate complex changes shape slightly to complete the fit
- locks substrate more tightly to the enzyme

17

What’s the induced fit model?

-substrate fits into enzyme active site
- as substrate binds the active site changes shape slightly
- enzyme-substrate complex formed
- products released

18

What do enzymes properties relate to?

Their tertiary structure

19

Are enzymes very specific ?

Yes

20

Why are enzymes specific?

Because only one complementary substrate will fit into the active site

21

What determines the enzymes active site?

The tertiary structure

22

Do all enzymes have different tertiary structure and so different active sites

Yes

23

What does it mean if tertiary structure is altered?

Shape of active site will change
-enzyme substrate won’t fit active siren
- so enzyme-substrate complex can’t be formed
- enzyme can’t carry out its function

24

How can the tertiary of the enzyme be changed?

By changes in pH or temperature

25

What’s the primary structure of a protein determined by?

A gene
- so If a mutation occurs in that gene, it could change the tertiary structure of the enzyme produced