Biochem Exam 4

Question 1

Triglycerides are broken down into
monoglycerides and free fatty acids,
by

Answer 1

lipase enzymes

Question 2

Chemical digestion begins in the
mouth by

Answer 2

lingual lipase

Question 3

Chemical digestion in the stomach
by

Answer 3

gastric lipase

Question 4

Lipoprotein

Answer 4

are group of soluble proteins that combine with and transport fat or other lipids in the blood plasma

Chylomicron
VLDL: very low-density lipoproteins: carry the synthesized triglycerides.
LDL: low-density lipoproteins: transport cholesterol to peripheral tissues.
HDL: high-density lipoproteins

Question 5

The breakdown of fatty acids is called fatty acid oxidation or β-oxidation

Answer 5

When glucose levels are low, triglycerides can be converted
into acetyl CoA molecules and used to generate ATP through aerobic respiration.

• Acetyl-CoA enters the Krebs cycle and is used to produce ATP in the same way as acetyl-CoA derived
  from pyruvate.
• Fats yield more energy per unit mass than carbohydrates

Question 6

Each round of beta-oxidation removes __ carbons from the fatty acid chain, releasing ___ acetyl-CoA,
which can then be oxidized in the citric acid cycle.

Answer 6

2, 1

Question 7

ketone bodies

Answer 7

acetone, acetoacetate, and 3-
hydroxybutyrate

Question 8

Amino acids must be obtained using 3 different ways

Answer 8

1) From the de novo synthesis
2) From the dietary intake of proteins
3) From the breakdown and turnover of endogenous proteins

Question 9

Amino acids can enter 3 metabolic
routes within the body

Answer 9

1) be recycled to synthesize new
proteins
2) combine with cofactors and
substances to create amino acid
derivatives
3) be catabolized into their functional
groups and carbon skeletons.
Amino acid derivatives
* Amino acids can be used to assemble
many substances.
* Amino acids (in blue) are combined
with certain cofactors or other
substrates (in pink) to make several
biologically-important substances (in
green).