Lecture 15: Glycolysis and Cellular Respiration

Question 1

Define catabolism

Answer 1

Degradation of complex molecules into simpler ones (Exergonic)

Question 2

Define anabolism

Answer 2

Synthesis of complex molecules (Endergonic)

Question 3

What is the relationship between catabolism and anabolism?

Answer 3

Energy from catabolism is used to perform anabolism

Question 4

What are the products of the breakdown of proteins?

Answer 4

Amino acids

Question 5

What are the products of the breakdown of polysaccharides?

Answer 5

Monosaccharides

Question 6

What are the products of the breakdown of lipids?

Answer 6

Glycerol + fatty acids

Question 7

Into which metabolic pathways are organic molecules converted?

Answer 7

Glycolysis or the Tricarboxylic Acid (TCA) cycle

Question 8

What happens to molecules that enter the TCA cycle?

Answer 8

They are oxidized completely to CO2, reducing NAD+ to NADH & FAD+ to FADH2

Question 9

What do NADH and FADH2 do during cellular respiration?

Answer 9

They feed into the electron transport chain (oxidative phosphorylation), releasing energy to create ATP

Question 10

List the three main stages of both aerobic and anaerobic respiration

Answer 10

• Glycolysis (Embden-Meyerhof)
• TCA cycle
• Electron transport

Question 11

What characterizes aerobic respiration?

Answer 11

O2 accepts electrons taken from organic materials

Question 12

What characterizes anaerobic respiration?

Answer 12

Some other inorganic electron acceptor accepts electrons taken from organic materials

Question 13

Define ATP Synthase

Answer 13

Multisubunit enzyme that acts as a proton channel and catalyzes ADP + Pi to ATP

Question 14

What do NADH and FADH2 do in aerobic respiration?

Answer 14

Donate electrons to cytochrome acceptors with more positive Eo

Question 15

What are cytochromes?

Answer 15

Proteins that contain iron ions and can undergo redox reactions

Question 16

What is the final electron acceptor in aerobic respiration?

Answer 16

O2, which is reduced to H2O

Question 17

How many ATPs are formed when NADH donates its electrons in aerobic respiration?

Answer 17

3 ATPs

Question 18

How many ATPs are formed when FADH2 donates its electrons in aerobic respiration?

Answer 18

2 ATPs

Question 19

What happens in anaerobic respiration regarding the final electron acceptor?

Answer 19

It is something other than O2 (e.g., NO3-, SO42-, CO2, S0, Fe3+)

Question 20

What determines the number of ATP produced in anaerobic respiration?

Answer 20

The Eo of the final electron acceptor

Question 21

What are facultative anaerobes?

Answer 21

Organisms that can use both aerobic and anaerobic respiration depending on oxygen availability

Question 22

What are obligate anaerobes?

Answer 22

Organisms that must use anaerobic respiration

Question 23

What is the total ATP yield from aerobic respiration?

Answer 23

38 ATPs

Question 24

What is the ATP yield from glycolysis during aerobic respiration?

Answer 24

2 ATPs from substrate-level phosphorylation and 6 ATPs from oxidative phosphorylation

Question 25

What happens to triglycerides in lipid catabolism?

Answer 25

They are broken down into glycerol and fatty acids by microbial lipases

Question 26

What is the role of glycerol in lipid metabolism?

Answer 26

It is modified (phosphorylated) and enters glycolysis

Question 27

What is beta-oxidation?

Answer 27

The process where fatty acids are broken down into 2C acetyl-CoA subunits

Question 28

What do proteases do in protein catabolism?

Answer 28

They digest proteins into amino acids

Question 29

What is deamination?

Answer 29

The removal of the amino group from amino acid

Question 30

What happens to deaminated amino acids?

Answer 30

They are converted into pyruvate, acetyl-CoA, or TCA cycle intermediates