5.2.2

Question 1

What is respiration?

Answer 1

The process whereby energy stored in complex organic molecules is used to make ATP, occurring in living cells.

Question 2

Define energy in the context of biology.

Answer 2

The capacity to do work, stored in complex molecules such as fats and carbohydrates.

Question 3

List metabolic reactions that require energy.

Answer 3

• Active Transport
• Secretion
• Anabolism
• Replication of DNA
• Endocytosis
• Movement
• Activation of chemicals

Question 4

What is ATP?

Answer 4

Adenosine triphosphate, a phosphorylated nucleotide consisting of adenine, ribose, and three phosphates.

Question 5

What happens when ATP is hydrolyzed?

Answer 5

It releases 30.6 kJ of energy per mol, converting to ADP and Pi.

Question 6

What is the role of ATP in cells?

Answer 6

It is the universal energy carrier, providing immediate energy for biological processes.

Question 7

What distinguishes anabolic reactions from catabolic reactions?

Answer 7

Anabolic reactions build larger molecules from smaller ones, while catabolic reactions break larger molecules into smaller ones.

Question 8

What is glycolysis?

Answer 8

An anaerobic metabolic pathway occurring in the cytoplasm that breaks down glucose into pyruvate.

Question 9

Where does the link reaction occur?

Answer 9

In the matrix of the mitochondria.

Question 10

What are the products of the link reaction?

Answer 10

• 2 CO2
• 2 NADH
• 2 acetyl CoA

Question 11

What is the Krebs cycle?

Answer 11

A series of reactions in the mitochondrial matrix producing ATP, NADH, and FADH2.

Question 12

Define oxidative phosphorylation.

Answer 12

The process where ATP is produced using the electron transport chain and chemiosmosis.

Question 13

What role do coenzymes play in respiration?

Answer 13

They help enzymes carry out oxidation reactions by accepting hydrogen atoms.

Question 14

What is NAD?

Answer 14

Nicotinamide adenine dinucleotide, a coenzyme involved in oxidation reactions during respiration.

Question 15

What is the function of coenzyme A?

Answer 15

To carry acetate groups to the Krebs cycle.

Question 16

What is the structure of mitochondria?

Answer 16

Rod-shaped organelles with an outer membrane, inner membrane, and matrix.

Question 17

What is chemiosmosis?

Answer 17

The process where protons flow through ATP synthase, driving ATP synthesis.

Question 18

What is the theoretical yield of ATP from one glucose molecule?

Answer 18

30 ATP molecules, although this is rarely achieved.

Question 19

What is anaerobic respiration?

Answer 19

The process of producing ATP without oxygen, primarily through glycolysis.

Question 20

What occurs during lactate fermentation?

Answer 20

Reduced NAD is oxidized to NAD, and pyruvate is reduced to lactate.

Question 21

What occurs during alcohol fermentation?

Answer 21

Pyruvate is decarboxylated to ethanal, which is then reduced to ethanol.

Question 22

Compare fast twitch and slow twitch muscle fibers.

Answer 22

• Fast twitch: Few mitochondria, fatigue easily, use glycolysis
• Slow twitch: Many mitochondria, slow to fatigue, operate aerobically

Question 23

What is a respiratory substrate?

Answer 23

An organic substance that can be used for respiration.

Question 24

Fill in the blank: The flow of protons through channel proteins during chemiosmosis produces _______.

Answer 24

ATP

Question 25

What color are twitch muscle fibres?

Answer 25

Dark red

Question 26

What do twitch muscle fibres contain many of?

Answer 26

Mitochondria

Question 27

How do twitch muscle fibres operate during exercise?

Answer 27

Aerobically for endurance exercise

Question 28

How can the rate of respiration be measured?

Answer 28

By measuring the rate of CO2 consumption

Question 29

What happens to pH as CO2 dissolves in the medium?

Answer 29

It lowers pH

Question 30

What is a respiratory substrate?

Answer 30

An organic substance that can be used for respiration

Question 31

What is the relationship between protons and ATP production?

Answer 31

The more protons, the more ATP produced

Question 32

List the three main types of respiratory substrates.

Answer 32

* Carbohydrate * Lipid * Protein

Question 33

What is the mean energy value for carbohydrates?

Answer 33

15.8 kJ g-1

Question 34

What is the mean energy value for lipids?

Answer 34

39.4 kJ g-1

Question 35

What is the mean energy value for proteins?

Answer 35

17.0 kJ g-1

Question 36

What is the general formula for carbohydrates?

Answer 36

Cn(H2O)n

Question 37

What is the chief respiratory substrate?

Answer 37

Glucose

Question 38

Which mammalian cells can only use glucose for respiration?

Answer 38

* Brain cells * Red blood cells

Question 39

How do animals store glucose?

Answer 39

As glycogen

Question 40

How do plants store glucose?

Answer 40

As starch

Question 41

What is the theoretical maximum energy yield for glucose?

Answer 41

2870 kJ mol-1

Question 42

How much energy is required to produce 1 mol of ATP?

Answer 42

30.6 kJ

Question 43

How many moles of ATP should theoretically be produced from 1 mol of glucose?

Answer 43

Nearly 94 mol ATP

Question 44

What is the actual yield of ATP from glucose respiration?

Answer 44

About 30 mol ATP

Question 45

What is the efficiency of glucose respiration?

Answer 45

About 32%

Question 46

What happens to the remaining energy during glucose respiration?

Answer 46

Released as heat

Question 47

What are triglycerides hydrolysed by?

Answer 47

Lipase

Question 48

What can glycerol be converted into for respiration?

Answer 48

Glucose

Question 49

What are fatty acids composed of?

Answer 49

Long-chained hydrocarbons

Question 50

What is formed from fatty acids during the β-oxidation pathway?

Answer 50

2-carbon acetyl groups

Question 51

What cycle do acetyl groups enter after being released from CoA?

Answer 51

Krebs cycle

Question 52

What is produced during the Krebs cycle for each acetate?

Answer 52

* 3 reduced NAD * 1 reduced FAD * 1 ATP

Question 53

What process produces large amounts of ATP during respiration?

Answer 53

Oxidative phosphorylation

Question 54

What is deamination?

Answer 54

The removal of the amine group and conversion to urea

Question 55

What can protein from muscle be hydrolysed to during fasting or prolonged exercise?

Answer 55

Amino acids

Question 56

What can some amino acids be converted to for the Krebs cycle?

Answer 56

Pyruvate or acetate

Question 57

True or False: Proteins release more energy than equivalent masses of carbohydrates.

Answer 57

True

Question 58

What device measures respiration rates?

Answer 58

Respirometer

Question 59

What decreases in the boiling tube as a result of respiration?

Answer 59

Volume of oxygen

Question 60

What absorbs carbon dioxide in the respirometer?

Answer 60

Soda lime

Question 61

What happens to air pressure in the boiling tube during respiration?

Answer 61

It decreases

Question 62

What is used to adjust the position of the fluid in the manometer?

Answer 62

Syringe

Question 63

What should be done to the second boiling tube in the experiment?

Answer 63

Serve as a control

Question 64

What should be done to exclude light when measuring respiration rates in photosynthetic organisms?

Answer 64

Wrap the tubes in foil or black paper