Essentials of Anatomy and Physiology

404 Body Temperature and Metabolism

Carbohydrates Fats

Fatty acid

Pyruvic acid

Acetyl CoA

Citric acid

(Beta

oxidation

in the liver)

Glucose Glycerol

ATP

ATP

ATP

H+

He

H+ H+ Cytochromes^34 ATP

Metabolic water

H 2 O

CO 2

H 2

H 2

FAD

NH 2

NH 2

NH 2

NH 2

NH 2

NH 2

H 2

NAD

NAD

Urea 3

4

C

C

C

C

C

C

C

C

C C

C

C C C C C C C C

C

C

C C C C C C

CCCCCC CCC

CCCCCCCC

CCCCCC

C C

C

C

C C

CC

C C C

CC

C

C

C

C

C

CO 2

CO 2

=

Oxygen

Proteins

Amino

acids

(Digestion) (Digestion) (Digestion)

2

Coenzyme A

Acetyl

groups

Oxaloacetic

acid

2

Figure 17–3. Schematic representation of cell respiration. The breakdown of glucose is

shown in the center, amino acids on the left, and fatty acids and glycerol on the right. See

text for description.

QUESTION:To which two molecules can all three food types be converted to enter the cit-

ric acid cycle?