Enzymes

Question 1

What are enzymes?

Answer 1

Proteins that act as a catalyst

- have a tertiary structure

Question 2

Do enzymes participate in chemical reactions?

Answer 2

No- they can be used over and over again

Question 3

What is the hydrolysis enzyme catalyzed reaction

Answer 3

2H2O2 -> 2H2O + O2

- catalase over the arrow

Question 4

Define active site

Answer 4

The binding site for substrate

Question 5

Compare the shape of a substrate and the active site

Answer 5

Have similar shape

Question 6

Define substrate

Answer 6

Any molecule that is recognized by an enzyme and binds to it

Question 7

What is formed when the substrate bonds to the enzyme?

Answer 7

Enzyme- substrate complex

Question 8

What happens to the enzyme in a catalyzed reaction?

Answer 8

It does not get used up and can be used for another reaction

Question 9

What happens to the enzyme active site when binding with substrate?

Answer 9

It changes its shape so it is a perfect fit to bind

Question 10

What is the substrate apart of when bonding to active site?

Answer 10

Tertiary structure

Question 11

Where is the enzyme written in a chemical reaction and why

Answer 11

Above the arrow because it doesn’t get used up

Question 12

Define induced fit model

Answer 12

A model of enzyme activity that describes how an enzyme active site changes shape to better accommodate for a substrate
- forms complementary shape

Question 13

What does it mean if you’re lactose intolerant?

Answer 13

You don’t have the enzymes (lactase) required to break down lactose

Question 14

Define activation energy

Answer 14

The energy required to start a chemical reaction. All chemical reactions require a certain amount of activation energy.
- usually heat

Question 15

How do enzymes affect activation energy and why?

Answer 15

Enzymes lower activation energy of chemical reactions, making them occur more readily (faster)

Question 16

What does the enzyme do when it lowers activation energy?

Answer 16

Breaks the barrier so it’s easier for substrate to turn into product

Question 17

Define a co-factor

Answer 17

A non protein atom or molecule that binds to an enzyme and is essential for catalytic activity
- (essential for enzymes to work)

Question 18

Give examples of co-factors

Answer 18

Minerals

Ex. Mg, Fe (iron in hemoglobin), K, Cu, Zn, Na

Question 19

Define co- enzyme

Answer 19

An organic molecule that acts as a co-factor

Question 20

Give examples of co- enzymes

Answer 20

Vitamins (A and B)

Question 21

What is the difference between vitamins and minerals,

Answer 21

Minerals are inorganic, vitamins are organic

Question 22

Why is the co- enzyme important?

Answer 22

Without it the substrate cannot bind

Question 23

How does enzyme concentration affect enzyme rate?

Answer 23

The more enzymes the faster the rate

Question 24

How does substrate concentration affect enzyme rate?

Answer 24

The more substrate the faster the rate

Question 25

Why does the curve flatten in an enzyme concentration graph?

Answer 25

The substrate ran out | - low in concentration

Question 26

Why does the curve flatten in a substrate concentration graph?

Answer 26

Rate stops increasing because enzymes ran out | -low in concentration

Question 27

How does pH affect enzyme rate?

Answer 27

When a substance moves away from its optimal pH level, the proteins denature and eventually drops to 0

Question 28

How does temperature affect enzyme rate?

Answer 28

When you move away from the optimal temperature, the protein either denatures (too hot) or the enzymes move too slow (too cold)

Question 29

Define enzyme inhibitor

Answer 29

Foreign agents that affect the enzymes ability to work | ex. venom or poison

Question 30

What do enzyme inhibitors do?

Answer 30

They lower the rate at which an enzyme catalyzes a reaction

Question 31

How do enzyme inhibitors lower the rate of a catalyzed reaction?

Answer 31

They bind to an enzyme and decrease its activity

Question 32

Where could enzyme inhibitors bind?

Answer 32

To the active site or other critical sites located elsewhere in the structure

Question 33

Define competitive inhibitor

Answer 33

Competitive inhibitor molecule resembles substrate and competes with the substrate for the active site

Question 34

Define noncompetitive inhibitor

Answer 34

Binds at the site other than the active site, causing the enzyme's shape to change so that substrate cannot bind to active site

Question 35

Is a competitive or non competitive inhibitor more dangerous?

Answer 35

The noncompetitive inhibitor is more dangerous because it shuts down the active site so that substrate cannot bind

Question 36

What determines if the substrate or inhibitor gets the spot on the active site?

Answer 36

Depends on if there is more substrate or more inhibitor

Question 37

What does cyanide do to the body?

Answer 37

Effects the mitochondria which prevents the body from using oxygen

Question 38

What is arsenic?

Answer 38

Rat poison

Question 39

What do pesticides do?

Answer 39

Chemically inhibit insect's enzymes

Question 39

What do pesticides do?

Answer 39

Chemically inhibit insect's enzymes

Question 40

What happens if someone has poison?

Answer 40

They pump the stomach to get rid of the inhibitor (empty the stomach)

Question 41

Define allosteric

Answer 41

Can be controlled

Question 42

Define allosteric regulators

Answer 42

Molecules in the body that naturally regulate enzyme activity by binding to an allosteric site on the enzyme

Question 43

Are allosteric regulators foreign?

Answer 43

No, they belong in your body

Question 44

What does it mean to naturally regulate an enzyme?

Answer 44

Control the enzymes by speeding them up or slowing them down

Question 45

What two things could allosteric regulation do?

Answer 45

Inhibit or stimulate enzyme activity

Question 46

Describe how an allosteric regulator may stimulate enzyme activity

Answer 46

1. enzyme binds to allosteric activator 2. binding activator converts enzyme to high affinity state 3. in high affinity state, enzyme binds substrate

Question 47

Describe how an allosteric regulator inhibits enzyme activity

Answer 47

1. enzyme binds allosteric inhibitor 2. binding inhibitor converts enzyme to low affinity state 3. substrate is released

Question 48

Why would the body want enzymes to work faster?

Answer 48

For the bodily functions to work

Question 49

Why would the body want enzymes to slow down?

Answer 49

There is too much product

Question 50

Define feedback inhibition

Answer 50

When the allosteric inhibitor is the final product in a biochemical pathway, it inhibits the enzyme that catalyzes the FIRST reaction in the pathway

Question 51

What happens if product is scarce?

Answer 51

The inhibition is reduced and the rate of the reaction increases

Question 52

Define biochemical pathway

Answer 52

A set of interconnected chemical reactions in which the substrate of the first reaction becomes the product. This product now becomes the substrate of the next reaction and so on...

Question 53

Which enzyme is allosteric in the biochemical pathway?

Answer 53

The first one

Question 54

What happens when there is a lot of product?

Answer 54

Enzyme 1 is inhibited and the pathway stops

Question 55

What happens if there is too little product?

Answer 55

The enzyme 1 is not inhibited anymore and the pathway restarts

Question 56

How to determine the number of reactions in a biochemical pathway?

Answer 56

The number of arrows

Question 57

What is each reaction in a biochemical pathway controlled by?

Answer 57

A different enzyme

Question 58

What is the purpose of a biochemical pathway?

Answer 58

To make the final product

Question 59

Where is pepsin used and what is the optimal pH

Answer 59

In the stomach, 2

Question 60

Where is trypsin used and what is the optimal pH

Answer 60

Intestine, 8

Question 61

Where is amylose used and what is the optimal pH

Answer 61

In the mouth, 7