Chapter 23

Where does most nutrient absorption occur?

in the small intestine, primarily in the jejunum

Cells perform catabolism to generate ATP, which can be used for all of the following except

diffusion

Lipogenesis generally begins with

acetyl-CoA.

All of the following is true of the electron transport system except

is found on the outer mitochondrial membrane.

The nutrients that yield the most energy per gram when metabolized are

lipids

What happens to the ammonium ions that are removed from amino acids during deamination?

they combine with CO2 and enter the urea cycle

In amino acid metabolism, identify the processes by which the amino group is removed

transamination or deamination

Linoleic acid and linolenic acid are examples of

essentially fatty acids

The process of synthesizing glucose from non-carbohydrates is called

gluconeogenisis

Glycolysis breaks down glucose into what?

pyruvate

In the process of digestion, most nutrient absorption takes place in the

small intestines

List the products of glycolysis.

2 molecules of pyruvate, 2 molecules of ATP, 2 molecules of NADH

________ carry excess cholesterol from peripheral tissues to the liver.

High density lipoproteins (HDL's)

`Describe the roles of LDLs and HDLs.

LDLs deliver cholesterol to tissues and HDLs absorb unused cholesterol and return it to the liver.

What two coenzymes transfer hydrogen atoms to the electron transport chain?

NAD, FAD

Explain why carbohydrates are preferred over proteins and lipids as an energy source.

Proteins and lipids are more important as structural components of cells and tissues.

Define oxidative phosphorylation.

The generation of ATP through the transfer of electrons from coenzymes to oxygen.

Metabolism can be defined as

anabolism + catabolism

Describe the source of intestinal gas.

bacterial metabolism of indigestible carbohydrates in the colon

The process that catalyzes fatty acids using enzymes that generate acetyl-CoA is called

beta-oxidation.

The lipoproteins that carry absorbed lipids from the intestinal tract to the bloodstream are the

chylomicrons.

Which of the following is not true of lipoprotein lipase?

decrease the breakdown of fatty acids

Which step of glucose metabolism yields the greater amount of ATP?

glycolysis + citric acid cycle