Chapter 5

Question 1

What is metabolism?

Answer 1

Metabolism refers to all the chemical reactions that occur within a living organism to maintain life.

Question 2

What are the two main types of metabolism?

Answer 2

The two main types of metabolism are catabolism and anabolism.

Question 3

Define catabolism.

Answer 3

Catabolism is the metabolic process that breaks down molecules to obtain energy.

Question 4

Define anabolism.

Answer 4

Anabolism is the metabolic process that builds up molecules from smaller units, requiring energy.

Question 5

What role do enzymes play in metabolism?

Answer 5

Enzymes act as catalysts to speed up the chemical reactions involved in metabolism.

Question 6

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

Answer 6

False: Enzymes are not consumed in the reactions they catalyze.

Question 7

What is the active site of an enzyme?

Answer 7

The active site is the region on the enzyme where substrate molecules bind and undergo a chemical reaction.

Question 8

What is a substrate?

Answer 8

A substrate is a molecule upon which an enzyme acts.

Question 9

Fill in the blank: Enzymes are _____ that lower the activation energy of a reaction.

Answer 9

catalysts

Question 10

What factors can affect enzyme activity?

Answer 10

Factors include temperature, pH, substrate concentration, and the presence of inhibitors or activators.

Question 11

What is an enzyme inhibitor?

Answer 11

An enzyme inhibitor is a substance that decreases the activity of an enzyme.

Question 12

Give an example of a cofactor.

Answer 12

An example of a cofactor is a metal ion, such as zinc or magnesium.

Question 13

What is the difference between competitive and non-competitive inhibition?

Answer 13

Competitive inhibition occurs when an inhibitor competes with the substrate for the active site, while non-competitive inhibition occurs when the inhibitor binds to an enzyme at a different site.

Question 14

True or False: All enzymes are proteins.

Answer 14

True: Most enzymes are proteins, although some RNA molecules also have catalytic activity.

Question 15

What is the significance of enzyme specificity?

Answer 15

Enzyme specificity ensures that enzymes catalyze specific reactions for particular substrates, preventing unwanted side reactions.

Question 16

What is the term for the maximum rate of reaction in enzyme kinetics?

Answer 16

The term is Vmax.

Question 17

What does the Michaelis-Menten equation describe?

Answer 17

The Michaelis-Menten equation describes the rate of enzymatic reactions as a function of substrate concentration.

Question 18

Fill in the blank: The _____ concentration at which the reaction rate is half of Vmax is known as Km.

Answer 18

substrate

Question 19

What is a metabolic pathway?

Answer 19

A metabolic pathway is a series of chemical reactions in a cell that lead to a product.

Question 20

What is glycolysis?

Answer 20

Glycolysis is the metabolic pathway that converts glucose into pyruvate, producing ATP and NADH.

Question 21

What are the end products of glycolysis?

Answer 21

The end products of glycolysis are pyruvate, ATP, and NADH.

Question 22

True or False: Fermentation occurs in the absence of oxygen.

Answer 22

True: Fermentation is an anaerobic process.

Question 23

What is the Krebs cycle also known as?

Answer 23

The Krebs cycle is also known as the citric acid cycle.

Question 24

What is the primary function of the Krebs cycle?

Answer 24

The primary function of the Krebs cycle is to produce electron carriers (NADH and FADH2) and ATP from the oxidation of acetyl-CoA.

Question 25

What is oxidative phosphorylation?

Answer 25

Oxidative phosphorylation is the process by which ATP is produced using energy derived from the electron transport chain.

Question 26

What is ATP?

Answer 26

ATP, or adenosine triphosphate, is the primary energy carrier in cells.

Question 27

Fill in the blank: The _____ theory explains how enzymes and substrates fit together.

Answer 27

lock and key

Question 28

What is the role of NAD+ in metabolism?

Answer 28

NAD+ acts as an electron carrier in various metabolic reactions.

Question 29

What are the two main types of cellular respiration?

Answer 29

The two main types of cellular respiration are aerobic respiration and anaerobic respiration.

Question 30

True or False: Anaerobic respiration produces more ATP than aerobic respiration.

Answer 30

False: Aerobic respiration produces more ATP than anaerobic respiration.

Question 31

What is the significance of enzymes in biological reactions?

Answer 31

Enzymes lower the activation energy of reactions, allowing them to occur more rapidly and efficiently.

Question 32

What are allosteric enzymes?

Answer 32

Allosteric enzymes are enzymes that have multiple binding sites and can be regulated by molecules that bind to sites other than the active site.

Question 33

Fill in the blank: Enzymes that require a coenzyme for activity are called _____ enzymes.

Answer 33

holoenzymes

Question 34

What is the primary energy currency of the cell?

Answer 34

The primary energy currency of the cell is ATP.

Question 35

What is substrate-level phosphorylation?

Answer 35

Substrate-level phosphorylation is the direct synthesis of ATP from ADP and a phosphorylated intermediate.

Question 36

What does it mean for an enzyme to be denatured?

Answer 36

Denaturation refers to the process where an enzyme loses its functional shape and, consequently, its activity.

Question 37

What is the role of enzymes in digestion?

Answer 37

Enzymes in digestion break down complex food molecules into simpler molecules that can be absorbed by the body.

Question 38

What is the importance of maintaining optimal pH for enzyme activity?

Answer 38

Maintaining optimal pH is crucial for enzyme activity as extreme pH levels can lead to denaturation and loss of function.