Enzyme and more ( Unit 3 )

Question 1

What are enzymes?

Answer 1

Biological catalysts that speed up chemical reactions in living organisms.

Question 2

True or False: Enzymes are consumed in the reactions they catalyze.

Answer 2

False

Question 3

What is the active site of an enzyme?

Answer 3

The region on the enzyme where substrate molecules bind.

Question 4

Fill in the blank: Enzymes are made up of ______.

Answer 4

Proteins

Question 5

What is the role of coenzymes?

Answer 5

They assist enzymes in catalyzing reactions.

Question 6

What is the effect of temperature on enzyme activity?

Answer 6

Increased temperature generally increases activity up to a point, after which it denatures.

Question 7

Define ‘substrate’.

Answer 7

The reactant molecule that an enzyme acts upon.

Question 8

What is cellular respiration?

Answer 8

The process by which cells convert glucose and oxygen into energy, carbon dioxide, and water.

Question 9

List the three main stages of cellular respiration.

Answer 9

Glycolysis, Krebs cycle, and Electron transport chain.

Question 10

True or False: Glycolysis occurs in the mitochondria.

Answer 10

False

Question 11

What is ATP?

Answer 11

Adenosine triphosphate, the energy currency of the cell.

Question 12

What is produced during glycolysis?

Answer 12

2 ATP, 2 NADH, and 2 pyruvate molecules.

Question 13

Fill in the blank: The Krebs cycle occurs in the ______.

Answer 13

Mitochondrial matrix

Question 14

What is the main purpose of the electron transport chain?

Answer 14

To produce ATP through oxidative phosphorylation.

Question 15

What are the end products of cellular respiration?

Answer 15

Carbon dioxide, water, and ATP.

Question 16

What is fermentation?

Answer 16

An anaerobic process that allows for the production of energy without oxygen.

Question 17

True or False: Lactic acid is produced during anaerobic respiration in muscle cells.

Answer 17

True

Question 18

What is the role of NAD+ in cellular respiration?

Answer 18

It acts as an electron carrier.

Question 19

Fill in the blank: The energy released during cellular respiration is stored in ______.

Answer 19

ATP

Question 20

What is the difference between aerobic and anaerobic respiration?

Answer 20

Aerobic respiration requires oxygen, while anaerobic respiration does not.

Question 21

What is the significance of the proton gradient in the electron transport chain?

Answer 21

It drives the synthesis of ATP via ATP synthase.

Question 22

What happens to pyruvate in the presence of oxygen?

Answer 22

It enters the Krebs cycle for further processing.

Question 23

Define ‘activation energy’.

Answer 23

The minimum energy required to initiate a chemical reaction.

Question 24

What is a competitive inhibitor?

Answer 24

A substance that competes with the substrate for the active site of the enzyme.

Question 25

True or False: Enzymes can work on any substrate.

Answer 25

False

Question 26

What is the role of oxygen in cellular respiration?

Answer 26

It acts as the final electron acceptor in the electron transport chain.

Question 27

Fill in the blank: The primary molecule that stores energy in cells is ______.

Answer 27

ATP

Question 28

What is glycolysis?

Answer 28

The breakdown of glucose into pyruvate, yielding ATP and NADH.

Question 29

What type of reaction do enzymes catalyze?

Answer 29

Chemical reactions.

Question 30

What is the end product of the Krebs cycle?

Answer 30

Carbon dioxide, ATP, NADH, and FADH2.

Question 31

What is the primary function of enzymes in metabolic pathways?

Answer 31

To lower the activation energy and increase the rate of reactions.

Question 32

True or False: Enzymes are specific to their substrates.

Answer 32

True

Question 33

What is the significance of feedback inhibition?

Answer 33

It regulates metabolic pathways by inhibiting enzymes when the end product is abundant.

Question 34

What does the term 'denaturation' refer to?

Answer 34

The alteration of an enzyme's structure, rendering it inactive.

Question 35

What is oxidative phosphorylation?

Answer 35

The process of generating ATP using the energy from the electron transport chain.

Question 36

Fill in the blank: The main electron carriers in cellular respiration are ______ and ______.

Answer 36

NADH and FADH2

Question 37

What is the role of ATP synthase?

Answer 37

To synthesize ATP from ADP and inorganic phosphate during oxidative phosphorylation.

Question 38

What is the function of enzymes in digestion?

Answer 38

To break down complex food molecules into simpler ones.

Question 39

True or False: Enzymes can function outside of their optimal pH range.

Answer 39

False

Question 40

What are the two stages of glycolysis?

Answer 40

Energy investment phase and energy payoff phase.

Question 41

What is the primary purpose of the Krebs cycle?

Answer 41

To produce electron carriers for the electron transport chain.

Question 42

Fill in the blank: The process of converting glucose into energy is called ______.

Answer 42

Cellular respiration

Question 43

What is substrate-level phosphorylation?

Answer 43

The direct transfer of a phosphate group to ADP to form ATP.

Question 44

What are the main products of fermentation in yeast?

Answer 44

Ethanol and carbon dioxide.

Question 45

True or False: The Krebs cycle occurs in the cytoplasm.

Answer 45

False

Question 46

What is the role of water in cellular respiration?

Answer 46

It is produced as a byproduct during aerobic respiration.

Question 47

What is a non-competitive inhibitor?

Answer 47

A substance that binds to an enzyme at a site other than the active site, reducing its activity.