Cellular Respiration Review

Question 1

Chem. rxns. where electrons are transferred from one molecule to another

Answer 1

Redox Reactions

Question 2

Molecules that can donate electrons; results in a decrease in potential energy

Answer 2

Reducing Agents

Question 3

Molecules that can accept electrons; results in an increase in potential energy

Answer 3

Oxidizing Agents

Question 4

Molecules that gain electrons after rxn.

Answer 4

Reduced

Question 5

Molecules that lose electrons after rxn.

Answer 5

Oxidized

Question 6

Most of the energy used to fuel cell function is in the form of what?

Answer 6

High-energy electrons

Question 7

Loss of phosphate group from a molecule

Answer 7

Dephosphorylation

Question 8

Why are phosphate groups inherently unstable?

Answer 8

They are negatively charged and repel one another when arranged in a series

Question 9

What is the process of adding a phosphate group to a molecule?

Answer 9

Phosphorylation

Question 10

Are phosphorylated molecules less stable?

Answer 10

Yes

Question 11

How is ATP generated?

Answer 11

ADP undergoes phosphorylation (ADP + Pi = ATP)

Question 12

What produces 90% of ATP?

Answer 12

Chemiosmosis (Oxidative Phosphorylation)

Question 13

What is the equation for cellular respiration?

Answer 13

C6H12O6 + 6O2 = 6CO2 + 6H2O + about 36 ATP

Question 14

What are the metabolic pathways involved in cellular respiration?

Answer 14

Glycolysis, Pyruvate Oxidation, Citric Acid Cycle, and Oxidative Phosphorylation (ETC & Chemiosmosis)

Question 15

How does glucose enter a cell?

Answer 15

Secondary active transport against a concentration gradient or GLUT proteins (facilitated diffusion)

Question 16

Where does glycolysis take place?

Answer 16

Cytoplasm

Question 17

What are the inputs for glycolysis?

Answer 17

1 glucose, 2 NAD+, 2 ATP, and 4 ADP

Question 18

What are the outputs for glycolysis?

Answer 18

2 pyruvate, 2 NADH, 4 ATP, and 2 ADP

Question 19

After the first half of glycolysis, why can’t glucose leave the cell via glucose transport proteins?

Answer 19

Negatively charged phosphate won’t allow glucose to cross plasma membrane

Question 20

What converts one isomer to another?

Answer 20

Isomerase

Question 21

How is glycolysis an example of end product inhibition?

Answer 21

More active when ADP is high and less active when ATP is high

Question 22

What are the 3 net changes in glycolysis?

Answer 22

1. Glucose converted to 2 molecules of pyruvate
2. 2 molecules of ADP converted to ATP
3. 2 molecules of NAD+ reduced to NADH

Question 23

What happens to pyruvate if O2 is present?

Answer 23

Oxidized to acetyl CoA which enters CAC

Question 24

What happens to pyruvate if O2 is not present?

Answer 24

Reduced to oxidize NADH back to NAD+ for fermentation

Question 25

Where does pyruvate oxidation take place in eukaryotes?

Answer 25

Mitochondria

Question 26

Where does pyruvate oxidation take place in prokaryotes?

Answer 26

Plasma Membrane

Question 27

What are the inputs of pyruvate oxidation?

Answer 27

2 pyruvate, 2 NAD+, 2 coenzyme A

Question 28

What are the outputs of pyruvate oxidation?

Answer 28

2 CO2, 2 NADH, 2 acetyl CoA

Question 29

Why are the steps of the CAC a closed loop?

Answer 29

Last part of the pathway regenerates compounds needed in first step, allowing cycle to run continuously when reactants are present

Question 30

Outputs per glucose at the end of CAC

Answer 30

4 ATP, 6 CO2, 10 NADH, 2 FADH2

Question 31

What happens to glucose at the end of the CAC

Answer 31

It's completely oxidized; all possible electrons have been removed

Question 32

Outputs of CAC

Answer 32

2 ATP, 4 CO2, 6 NADH, 2 FADH2

Question 33

What is the only pathway where O2 is an input?

Answer 33

Oxidative Phosphorylation

Question 34

What provides the energy to power chemiosmosis?

Answer 34

H+ concentration gradient created by the ETC

Question 35

What is the electron transport chain?

Answer 35

Series of e- transporters embedded in inner mitochondrial membrane

Question 36

What does the ETC do?

Answer 36

Shuttle e- from NADH and FADH2 to O2

Question 37

What happens to O2 in the ETC?

Answer 37

Reduced to form H2O

Question 38

How does chemiosmosis form ATP?

Answer 38

Uses KE from protons falling down H+ gradient to form ATP from ADP + Pi

Question 39

How much ATP is generated by cellular respiration per glucose?

Answer 39

30-36

Question 40

Why must cellular respiration be regulated?

Answer 40

1. Provide balanced amt. of energy in form of ATP without being wasteful 2. Generate a number of intermediate compounds that are used in forming macromolecules

Question 41

How are carbs stored for short-term use in animals?

Answer 41

As glycogen in liver and muscle tissue

Question 42

What dietary sugars produce the same number of ATP molecules as glucose?

Answer 42

Fructose & Galactose