Chapter 3 PowerPoint

Question 1

Bioenergetics

Answer 1

Process of converting foodstuffs (fats, proteins, carbohydrates) into useable energy for cell work.

Question 2

What does NAD and FAD do in the electron transport chain?

Answer 2

They transport electrons and hydrogen ions.

Question 3

What is the optimal pH for enzyme activity?

Answer 3

7-8

Question 4

How do enzymes catalyze reactions?

Answer 4

Enzymes lower the energy of activations.

Question 5

Examples of the diagnostic value of enzymes found in blood…

Answer 5

1. Lactate dehydrogenase (cardiac-specific isoform) - myocardial infarction
2. Creatine kinase - myocardial infaction, muscular dystrophy
3. Alkaline phosphatase - carcinoma of bone, Paget’s disease, obstructive jaundice
4. Amylase - Pancreatitis, perforated peptic ulcer
5. Aldolase - Muscular dystrophy

Question 6

The effect of body temperature on enzyme activity…

Answer 6

Enzyme activity increases until the body reaches normal body temperature 37 C. Enzyme activity increases slightly until the body temperature reaches 40 C, and then enzyme activity decreases after that.

Question 7

Fuels for exercise

Answer 7

Glucose (blood sugar)
Glycogen (storage form of glucose in liver and muscle)

Fatty acids (primary type of fat used by skeletal muscle)
Triglycerides (storage form of fat in muscle and adipose tissue)

Protein (glucogenesis = amino acid converted to glucose in the liver. Converted into metabolic intermediates, which is used as a fuel in muscle)

Question 8

Bioenergetics: anaerobic pathways

Answer 8

Does not involve O2.

Phosphocreatin breakdown and glycolysis.

Question 9

Bioenergetics: aerobic pathways

Answer 9

Requires O2.

Oxidative phosphorylation.

Question 10

Does creatine supplementation improve exercise performance?

Answer 10

Depletion of phosphocreatine may limit short-term, high-intensity exercise.
Creatine monohydrate supplementation increase muscle phosphocreatine stores. Some studies show increase in performance in short-term, high-intensity exercise. But there is inconsistent results may be due to water retention and weight gain. Increase strength and fat-free mass with resistance training.
Does not appear to pose health risks.
Variability in supplement purity exists.

Question 11

2 phases of glycolysis

Answer 11

Energy investment phase

Energy production phase

Question 12

Input; output of glycolysis

Answer 12

1 glucose; 2 pyruvate of 2 lactate
2 ADP; 2 ATP
2 NAD+; 2 NADH

Question 13

Pyruvic acid conversation to lactic acid

Answer 13

Addition of two H to pyruvic acid forms NAD+ and lactic acid. This is catalyzed by lactate dehydrogenase (LDH).

Question 14

How do you differentiate between lactate and lactic acid?

Answer 14

The ionization of lactic acid forms the conjugate base called lactate.
Glycolysis rapidly disassociates to lactate and H+.

Question 15

How many NADH are produced from the Kreb’s cycle?

Answer 15

10 NADH

Due to 2 pyruvates coming from glycolysis.

Question 16

Beta oxidation is the process of converting fatty acids to…

Answer 16

Acetyl CoA

Question 17

Beta Oxidation

Answer 17

Breakdown of triglycerides releases fatty acids.
Fatty acids must be converted to acetyl-CoA to be used as fuel.
Acetyl-CoA enters the citric acid cycle.

Question 18

Efficiency of oxidative phosphorylation

Answer 18

One mole of ATP has energy yield of 7.3 kcal.
32 moles of ATP are formed from one mole of glucose.
Potential energy released from one mole of glucose is 686 kcal/mole.
Overall efficiency of aerobic respiration is 25-35%. 66% of energy is released as heat.