Bioenergetics

Question 1

ATP and the PCr system

Answer 1

PCr keeps ATP around longer for the beginning of exercise

PCr + ADP Cr + ATP….converts with creatine kinase enzyme

Question 2

Type of oxygen availability during shot-term high-intensity exercise?

Answer 2

Anaerobic energy systems

example: ATP- PCr system

Question 3

Type of oxygen availability during long-term low to moderate-intensity exercise?

Answer 3

Aerobic sources

example: Oxidative phosphorylation

Question 4

Immediate energy source?

Answer 4

ATP-PCr system

Anaerobic pathway

Question 5

Short-term energy source?

Answer 5

Glycolysis

Anaerobic Pathway

Question 6

Long-term energy source?

Answer 6

Aerobic/Oxidative phosphorylation/ ETC

Question 7

Glycolysis

Answer 7

Breakdown of glucose or glycogen
Beginning steps of the Kreb’s cycle
Final products produced from reaction: 2 pyruvate or lactate, 2 ATP (had 4 but used 2 during reaction), 2 NADH,

Question 8

What happens if not enough oxygen is available?

Answer 8

Form lactate instead of pyruvate

One fate of pyruvate!!

Question 9

What enzyme is used to convert pyruvic acid to lactic acid?

Answer 9

Lactate dehydrogenase (LDH)

Question 10

What are the fates of pyruvate?

Answer 10

All occur in the matrix of the mitochondria

1. Produce lactate when oxygen is not present
2. Produce Pyruvate Carboxilase (PC)
3. Produce Pyruvate Dehydrogenase

Question 11

Pyruvate Dehydrogenase

Answer 11

The enzyme that converts pyruvate to Acetyl CoA which enters the Kreb’s cycle

Question 12

Where does glycolysis occur?

Answer 12

cytoplasm

NOT the mitochondria

Question 13

How many turns of the Krebs Cycle does the break down of glucose yield?

Answer 13

2 tuns b/c produced 2 pyruvate which produced 2 Acetyl CoA

Question 14

What is produced from1 turn of the Krebs Cycle?

Answer 14

1 GTP, 3 NADH, 1 FADH2, 2 CO2

1-3-1 rule

Question 15

Where does the Krebs Cycle take place?

Answer 15

Matrix of the mitochondria

Question 16

What is produced from the ETC?

Answer 16

2.5 ATP per NADH
1.5 ATP per FADH2
Water

Question 17

Rate Limiting Step

Answer 17

Step with the highest amount of energy that needs to be overcome
Example: In glycolysis: PFK is rate limiting enzyme (phosopfructokinase)- important because: PFK affected, glycolysis affected

Question 18

Kreb’s Cycle Steps

Answer 18

2 pyruvate –> release 2 NADH2 and 2 CO2 –> PDH converts 2 Acetyl CoA –> combines with OOA –> Citrate
Gain 1 GTP, 3 NADH, 1 FADH2 and 2 CO2

Question 19

What is Beta Oxidation?

Answer 19

Catabolism of fatty acids in the mitochondria matrix to Acetyl CoA
Fats require more oxygen to burn

Question 20

Carnitine

Answer 20

Transfers fatty acids to mitochondria matrix for Beta Oxidation

Question 21

What does Oxaloacetate (OOA) require?

Answer 21

Carbohydrates to keep it filled with 4 carbons so Acetyl CoA can bind for fat metabolism (Pyruvate carboxylase important in this step)

Question 22

What are the products from Beta Oxidation per round?

Answer 22

1 Acetly CoA, 1 FADH2, 1 NADH
Take each product times its respective ATP number
Get over 100 ATP from 1 mole of fat

Question 23

Rate Limiting Enzymes

Answer 23

Allosteric Modulation - control rate of metabollic pathway
1. ATP-PCr = creatine Kinase
2. Glycolysis = Phosphofructokinase
3. Krebs Cycle = Isocitrate Dehydrogenase
4. ETC = Cytochrome Oxidase
Example: Stimulate PFK –> produce more pyruvate

Question 24

Oxygen Availability

Answer 24

1. Sufficient O2 – pyruvate enters mitochondria (aerobic)

2. Insufficient O2- pyruvate converts to lactate in sarcoplasm (anaerobic)

Question 25

What inhibits the Krebs Cycle pathway?

Answer 25

1. Products of metabolic pathways can act as feedback inhibitors (citrate, ACoA, pyruvate)
2. High ATP inhibits pathways
3. High ADP or AMP would stimulate pathway

Question 26

Allosteric Modulation

Answer 26

Too much NADH will inhibit different areas around the Kreb’s Cycle
Too much Citrate will inhibit the citrase enzyme