Proteins Topic 16 Part1

Question 1

Explain how the drugs lowers the rate of reaction controlled by floate reductase?

Question 2

What is a catalyst? And what does it do?

Answer 2

It is a substance that speeds up reaction without being used up itself

Question 3

What is the role of enzymes in biological processes?

Answer 3

Enzymes act as biological catalysts that speed up the rate of chemical reactions in living organisms.

Question 4

Define the term ‘active site’ in enzymes.

Answer 4

The active site is the specific region of an enzyme where substrate molecules bind.

Question 5

What is meant by ‘activation energy’?

Answer 5

Activation energy is the minimum amount of energy required for a chemical reaction to occur.

Question 6

Explain the ‘lock and key’ model of enzyme action.

Answer 6

The lock and key model suggests that the substrate fits precisely into the active site of the enzyme, like a key fits into a lock.

Question 7

What happens in “induced fit hypothesis”?
What is “fit induced model” ?

Answer 7

It is too simplistic
Where the substrate molecules cause the enzymes active site to change shape, as the structure binds to its active site. Which this locks the substrate in even more tightly to the enzymes.

And this is called induced “fit model”.

Question 8

List the factors that can change the rate of reaction of enzymes.

Answer 8

• Temperature
• pH
• Substrate concentration
• Enzyme concentration

Question 9

What happens to enzymes at high temperatures?

Answer 9

Enzymes can become denatured, losing their functional shape and activity.

Question 10

True or False: Enzyme inhibitors can increase enzyme activity.

Answer 10

False

Question 11

What are competitive inhibitors?

Answer 11

Competitive inhibitors are molecules that resemble the substrate and compete for the active site of the enzyme.

Question 12

What effect does increasing substrate concentration have on competitive inhibitors?

Answer 12

Higher substrate concentration increases the chances of substrate binding to the active site before the inhibitor.

Question 13

Describe non-competitive inhibitors.

Answer 13

Non-competitive inhibitors bind to an enzyme away from the active site, causing a change in shape that reduces enzyme activity.

Question 14

How does cyanide affect enzyme activity?

Answer 14

Cyanide inhibits the enzyme cytochrome c oxidase, which is involved in aerobic respiration and ATP production.

Question 15

Fill in the blank: The _____ model of enzyme action describes how the active site changes shape when the substrate binds.

Answer 15

[induced fit]

Question 16

What is the optimum pH for pepsin?

Answer 16

2

Question 17

How can you measure the rate of an enzyme-catalyzed reaction?

Answer 17

By calculating the change in product concentration over time.

Question 18

What is the significance of the saturation point in enzyme kinetics?

Answer 18

At the saturation point, all active sites are occupied, and increasing substrate concentration will not increase the rate of reaction.

Question 19

What is a key characteristic of enzymes related to their tertiary structure?

Answer 19

Enzymes are specific, with different enzymes having different tertiary structures and active sites.

Question 20

What can cause enzymes to denature?

Answer 20

High temperatures and extreme pH levels can cause denaturation.

Question 21

Explain how enzyme inhibitors can be classified.

Answer 21

• Competitive inhibitors
• Non-competitive inhibitors

Question 22

What is the relationship between enzyme concentration and reaction rate?

Answer 22

Higher enzyme concentration generally increases the rate of reaction, provided substrate is available.

Question 23

What does “denatured” mean?

Answer 23

It means the breaking up of protein/ or the substrate will no longer fits into the enzyme

Question 24

What does “Anabolic” means?

Answer 24

Anabolic means building up or storing molecules.

It’s a part of metabolism, which is the sum of all the chemical and physical processes that convert and use energy in the body

Question 25

What does “Catabolic”mean?

Answer 25

1. Catabolic means the process of breaking down large or complex molecules into smaller one. 2. Such as proteins or lipids to provide energy 3. Then this energy is used for other functions in the body such as building molecules or producing body heat.

Question 26

What does “product” means in enzymes?

Answer 26

The product is the molecule that results from an enzyme's chemical reaction with a substrate

Question 27

What does “specific” means in enzymes?

Answer 27

It means that an enzyme can only catalyze a particular chemical reaction with a specific molecule (called a substrate)

Question 28

What is intracellular?

Answer 28

1. Are enzymes that are produced and function within a cell. 2. Intracellular enzymes are protein particles that are the main catalysts for most biological processes. 3. They are found in the cytoplasm and in organelles like the mitochondria, nucleus, and lysosomes. 4. Intracellular enzymes are responsible for many cellular processes, including cellular respiration, photosynthesis, and intracellular digestion

Question 29

What is Extracellular?

Answer 29

1. It Function outside the cell: extracellular enzymes are released into the extracellular fluid to perform their catalytic activity. 2. Role in digestion and decomposition: break large, complex molecules such as carbohydrates and proteins