Cellular Respiration (Cliff Notes)

Question 1

What are the 3 components of aerobic respiration?

Answer 1

Glycolysis, Krebs cycle, and oxidative phosphorylation

Question 2

What is cellular respiration?

Answer 2

It is an ATP-generating process that occurs within cells. In the presence of oxygen, it is called aerobic respiration.

Question 3

What is the end product of glycolysis?

Answer 3

2 pyruvate

Question 4

What are the intermediate products formed in glycolysis/.

Answer 4

2 ATP net (4 ATP produced total), 2 NADH, 2 pyruvate

Question 5

Where does glycolysis take place in the cell?

Answer 5

In the cytosol

Question 6

What is the subsequent reaction for pyruvate in aerobic respiration?

Answer 6

Pyruvate combines with coenzyme A and NAD+ to make Acetyl CoA, NADH, and CO2. This reaction is catalyzed by Pyruvate Dehydrogenase Complex

Question 7

What are products of the Krebs cycle?

Answer 7

1 cycle produces 3 NADH, 1 FADH2, 1 ATP, and 1 CO2 (remember that 1 molecule of glucose produces 2 pyruvate)

Question 8

What is oxidative phosphorylation?

Answer 8

It is the process of extracting ATP from NADH and FADH2 as their electrons are passed along an electron transport chain.

Question 9

What is the electron transport chain composed of?

Answer 9

It is composed of proteins that pass electrons from NADH and FADH2 from one carrier protein to the next. Along each step of the chain, the electrons give up energy used to by ATP synthase to phosphorylate ADP to ATP.

Question 10

How many ATP are generated from NADH in the ETC?

Answer 10

About 3 ATP

Question 11

How many ATP are generated from FADH2 in the ETC?

Answer 11

About 2 ATP

Question 12

Which protein is often compared among species to assess genetic relatedness?

Answer 12

Cytochrome c, one of the carrier proteins in the electron transport chain - because it is so ubiquitous among living organisms

Question 13

How many ATP?

Answer 13

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Question 14

What are the 4 distinct areas of the mitochondria?

Answer 14

Outer membrane, inter membrane space, inner membrane, Matrix

Question 15

Where does oxidative phosphorylation occur?

Answer 15

It takes place in the convolutions (cristae) of the inner membrane of the mitochondria

Question 16

What is chemiosmosis?

Answer 16

It is the mechanism of ATP generation that occurs when energy is stored in the form of a proton concentration across a membrane

Question 17

What is substrate level phosphorylation and where does it take place?

Answer 17

When a substrate molecule (containing the phosphate group) donates the high energy group to ADP to form ATP (ie: 1,3-Bisphosphoglycerate is converted to 3 phosphoglycerate and gives off ATP by the enzyme phosphoglycerate kinase)

Question 18

What is oxidative phosphorylation?

Answer 18

The phosphorylation of ADP to make ATP using an electron transport chain that creates an electron gradient that powers ATP synthase

Question 19

What happens in the absence of oxygen?

Answer 19

If oxygen is not present, no electron acceptor exists to accept the electrons at the end of ETC. If this happens, NADH accumulates, cycles stop, no new ATP is produced and the cell dies. To escape this fate, anaerobic respiration occurs to replenish NAD+

Question 20

What are two common metabolic pathways of anaerobic respiration?

Answer 20

Alcohol Fermentation and Lactic Acid Fermentation

Question 21

In which organisms does alcohol fermentation occur?

Answer 21

Plants, fungi (such as yeasts), and bacteria

Question 22

Does glycolysis stop during anaerobic respiration?

Answer 22

No it occurs alongside aerobic respiration in the cytosol - in fact, the goal of anaerobic respiration is to allow glycolysis to continue by releasing some NAD+ for use in glycolysis