Bioenergetics - Chap 3

Question 1

Define Metabolism

Answer 1

All chemical reactions in the body that result in:

Catabolism: breakdown of cell components/molecules

Anabolism: build up of cell components/molecules

Question 2

Define Bioenergetics

Answer 2

Metabolic pathways specifically involved converting food into energy

Question 3

In what form is Glucose stored in the body?

Answer 3

Glycogen

Question 4

In what form is Fat stored in the body?

Answer 4

Triglycerides

Question 5

What are the primary sites for Glucose storage in the body?

Answer 5

Liver and Muscle

Question 6

What are the primary sites for Fat storage in the body?

Answer 6

Muscle and Adipose tissue

Question 7

What is the 1st law of Thermodynamics?

Answer 7

Energy is not created or destroyed but transfers from one form to another

Question 8

What is the 2nd law of Thermodynamics?

Answer 8

Transfer of potential energy always proceeds in direction that decreases the capacity to perform work (conversion to heat is ultimate fate of chemical energy)

Question 9

What is Anaerobic?

Answer 9

1. Does not require O2
2. Phosphocreatine breakdown and Glycolysis

Question 10

What is Aerobic?

Answer 10

1. Requires O2
2. Oxidative Phosphorylation

Question 11

How efficient is the the process of bioenergetics?

Answer 11

Not efficient

Question 12

What is the percent energy released from our nutrients is captured by ADP to synthesize ATP? versus released as heat?

Answer 12

25% captured by ADP to synthesize ATP versus 75% released as heat

Question 13

Why do athletes ingest creatine to improve exercise performance?

Answer 13

1. Immediate source of energy in muscle
2. The larger our PCr reserves, the longer we can sustain intense muscular activity

Question 14

Identify the cellular location for Anaerobic Metabolism (glycolysis)

Answer 14

Cytoplasm (Glycolysis)

Question 15

Identify the cellular location for Aerobic Metabolism (3 stages)

Answer 15

Mitochondria (Glycolysis, Krebs Cycle, ETC)

Question 16

What nutrient can only be broken down by Glycolysis?

Answer 16

Glucose (carbohydrates)

Question 17

The end product of glycolysis has two options. What are they?

Answer 17

1. In absense of sufficient oxygen pyruvate is converted to Lactate
2. If oxygen is available. Enter Mitochondria and be converted into Acetyl CoA for further Oxidation.

Question 18

What are the 3 stages of aerobic metabolism?

Answer 18

1. Generation of Acetyl CoA
2. Krebs Cycle
3. ETC

Question 19

What are the events necessary (in order) required for full oxidation of a molecule of glucose?

Answer 19

1. Generation of Acetyl CoA
2. Krebs Cycle
3. ETC

Question 20

What are NAD and FAD and why are they important?

Answer 20

NAD and FAD are energy carriers. They are the oxidizing agents and accept electrons.

Question 21

Why is oxygen so important for aerobic metabolism - and life in general?

Answer 21

1. Allows for ETC to function
2. If the last cytochrome retained the electrons. it wouldn’t be able to accept more, and the ETC would STOP
3. It can accept the electrons from NADH and allow for continuous electron flow

Question 22

Who can oxidize Fat and Protein?

Answer 22

Oxidized by aerobic metabolism

Question 23

Individual fatty acids from the triglyceride molecule will do what?

Answer 23

Cleaved into 2 carbon molecules (Acetyl CoA) by the process of Beta Oxidation

Question 24

What is the rate limiting enzyme for PCr? and the primary modulator?

Answer 24

1. Creatine Kinase(CK)
2. ADP increases and is inhibited by high levels of ATP

Question 25

What is the rate limiting enzyme for Glycolysis? and the primary modulator?

Answer 25

1. Phosphofructokinase (PFK)
2. ADP + Pi rise and enhance PFK activity

Question 26

What is the rate limiting enzyme for the Krebs Cycle? and the primary modulator?

Answer 26

1. Isocitrate Dehyrogenase
2. Inhibited by ATP and Stimulated by increasing levels of ADP + Pi