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