2.2 Cell Respiration

Question 1

What is ‘Respiration’?

Answer 1

A series of enzyme controlled reactions to breakdown glucose and release ATP

Question 2

What is the word equation for respiration?

Answer 2

Glucose + Oxygen –> Carbon Dioxide + Water

Question 3

What is the preferred respiratory substrate?

Answer 3

Glucose

Question 4

What does ATP stand for?

Answer 4

Adenosine TriPhosphate

Question 5

What are the two main roles of ATP?

Answer 5

1. Act as energy transfer molecules

2. Carry out phosphorylation of molecules

Question 6

What is ‘Phosphorylation’

Answer 6

Addition of an inorganic phosphate molecule

Question 7

What is the reduced state of NAD?

Answer 7

NADH

Question 8

Describe Reduction and Oxidation in terms of FAD

Answer 8

FAD - Oxidized State(loss of electrons)

FADH2- Reduced State(Gain of electrons)

Question 9

What is the role of coenzymes in respiration?

Answer 9

Collect hydrogen ions and high energy electrons and deliver them to stage 3 of aerobic respiration

Question 10

What is the role of dehydrogenase enzymes?

Answer 10

Remove hydrogen ions and high energy electrons during breakdown of glucose and pass them to coenzymes

Question 11

What is the first stage of respiration?

Answer 11

Glycolysis

Question 12

Where does Glycolysis occur?

Answer 12

Cytoplasm

Question 13

What are the two stages known as in glycolysis?

Answer 13

Energy investment and Energy Payoff

Question 14

What is meant by ‘Net gain of 2 ATP in Glycolysis’

Answer 14

• Invest 2 ATP
• Releases 4 ATP
  Two more ATP that put in

Question 15

What happens in animals after glycolysis in the absence of oxygen?

Answer 15

Pyruvate is converted into Lactic Acid

Question 16

What is the end product of glycolysis?

Answer 16

Pyruvate

Question 17

Is the conversion of pyruvate to lactic acid reversible or irreversible?

Answer 17

Reversible

Question 18

What is pyruvate converted into in the absence of oxygen in yeast cells?

Answer 18

Ethanol and C02

Question 19

What is energy from the breakdown of ATP used for?

Answer 19

Muscle Contraction
Repair of Cells
Transport

Question 20

What is the optimum temperature for dehydrogenase enzymes?

Answer 20

37 degrees (human body temperature)

Question 21

What is the second stage of aerobic respiration?

Answer 21

Citric Acid Cycle

Question 22

Where does the Citric Acid Cycle Occur?

Answer 22

Matrix of Mitochondria

Question 23

How many carbons does Pyruvate contain?

Answer 23

3 Carbons

Question 24

What does the citric acid cycle result in?

Answer 24

• Generation of ATP
• Release of CO2
• Regeneration of Oxaloacetate

Question 25

What happens to pyruvate before it becomes part of the cycle?

Answer 25

Converted into Acetyl Group, and then combines with coenzyme A to form Acetyl CoA

Question 26

What is released in the conversion of pyruvate to Acetyl CoA?

Answer 26

CO2 | NADH

Question 27

How many carbons does Acetyl CoA contain?

Answer 27

2 Carbons

Question 28

What does Acetyl CoA combine with to form citric acid?

Answer 28

Oxaloacetate

Question 29

How many carbons does oxaloacetate contain?

Answer 29

4 carbons

Question 30

At what two stages in the citric acid cycle is CO2 released?

Answer 30

During conversion of Pyruvate to Acetyl Group and during the conversion of Citric Acid to Oxaloacetate

Question 31

What are the key products from stage 1 and 2 that are transported to stage 3?

Answer 31

NADH and FADH2

Question 32

How many carbons does Citric Acid contain?

Answer 32

6 carbons

Question 33

What do hydrogenase enzymes pass to coenzymes?

Answer 33

High energy electrons | Hydrogen Ions

Question 34

What is the final stage in aerobic respiration?

Answer 34

Electron Transport Chain

Question 35

Where does the electron transport chain take place?

Answer 35

Inner membrane folds of the mitochondria(Cristae)

Question 36

********What is the final hydrogen/electron acceptor? ********

Answer 36

OXYGEN

Question 37

Why do we need to breathe in every few seconds (in relation to respiration)?

Answer 37

In order to provide oxygen as the final hydrogen/electron acceptor

Question 38

Describe the steps in the electron transport chain?

Answer 38

- High energy electrons pump hydrogen ions across the membrane (provided by NADH and FADH2) - Return flow of hydrogen ions generate ATP Synthase - ATP synthase phosphorylates ADP to form ATP - Oxygen bonds with hydrogen and electrons to form Water

Question 39

Describe the roles of NADH and FADH2 in the electron transport chain?

Answer 39

NADH and FADH2 provide hydrogen ions and high energy electrons. The high energy electrons are used to pump the hydrogen ions across the membrane.

Question 40

What can be used as an alternative respiratory substrate for Glucose?

Answer 40

Fructose and Maltose etc | Starch and Glycogen (Broken down forms)

Question 41

What can be used as an alternative respiratory substrate for pyruvate?

Answer 41

Glycerol and Amino Acids

Question 42

What can be used as an alternative respiratory substrate for acetyl CoA?

Answer 42

Fatty Acids and Amino Acids

Question 43

What is the only type of molecule that can be an alternative respiratory substrate for an intermediate of the citric acid cycle?

Answer 43

Protein(Amino Acid)

Question 44

What is released when amino acids are used as a respiratory substrate/

Answer 44

Urea

Question 45

Name the two hydrogen carriers in aerobic respiration

Answer 45

NAD and FAD