A&P Chapter 23 mastering questions
________ carry excess cholesterol from peripheral tissues to the liver.
High-density lipoproteins (HDLs)
________ creates 90 percent of the ATP normally generated.
Oxidative phosphorylation
Which is true regarding lipoproteins and lipid transport and distribution?
The HDLs return the unused cholesterol to the liver, where it is extracted and packaged in new LDLs or excreted with bile salts in bile
In the absorptive state of metabolic activity:
androgens, estrogens, and growth hormone stimulate protein synthesis
Which form of glucose metabolism yields the greater amount of ATP?
electron transport system
Linoleic acid and linolenic acid are examples of
essential fatty acids
A drug that blocks the action of lipoprotein lipase would
interfere with triglyceride utilization prolong the circulation time of chylomicrons
The sum of all of the biochemical processes going on within the human body at any given time is called
metabolism
When chyme arrives in the duodenum, cholecystokinin (CCK) release triggers the secretion of which enzyme?
pancreatic alpha-amylase
Glycolysis breaks down glucose into what?
pyruvate
The function of the citric acid cycle is to
remove hydrogen atoms from organic molecules and transfer them to coenzymes
In transamination, the amino group of an amino acid is ________, yielding a different amino acid.
transferred to another molecule
The conversion of ammonia into a less toxic substance produces
urea
All of the following take place during the absorptive state except
ketone bodies begin to form
All of the following occur during the postabsorptive state except that
levels of blood glucose are elevated
The nutrients that yield the most energy per gram when metabolized are
lipids
Urea is formed in the
liver
In oxidative phosphorylation, energy for the synthesis of ATP is directly obtained from the
movement of hydrogen ions through channels in the inner mitochondrial membrane
Reactions within ________ provide most of the energy needed by a typical cell.
the mitochondria
Glucocorticoids have which of the following effects on general peripheral tissues?
-They increase glycogenolysis -They increase gluconeogenesis -They increase the conversion of amino acids to pyruvate
Cells synthesize new organic components for which of the following reasons?
-production of secretions -growth and repair -structural maintenance
In the ETS, ________ accepts electrons from one molecule and transfers them to another.
a coenzyme or a cytochrome
Which is the common substrate for mitochondria in the citric acid cycle?
acetate
Lipogenesis generally begins with
acetyl-CoA
The process that catalyzes fatty acids using enzymes that generate acetyl-CoA is called
beta-oxidation
Identify the molecule labeled "2."
carbon dioxide
The largest lipoproteins, ________, are produced by intestinal epithelial cells from the fats in food.
chylomicrons
The lipoproteins that carry absorbed lipids from the intestinal tract to the bloodstream are the
chylomicrons
Identify the molecule labeled "5."
citric acid
Poisons like cyanide bind to ________ and prevent electron transfer.
cytochromes
In the postabsorptive state of metabolic activity, __________.
glucocorticoids stimulate the mobilization of lipid and protein reserves
The process of synthesizing glucose from noncarbohydrates is called
gluconeogenesis
Which process describes the synthesis of glucose from noncarbohydrate sources?
gluconeogenesis
All of the following are reasons why glucose is the primary energy source for cells except
glycogen breakdown occurs very slowly
Which condition results when body fluids become saturated with uric acid?
gout
Glucose:
is transported to the liver by way of the hepatic portal vein
Fatty acids that are necessary for proper health but cannot be synthesized by the body are called
essential fatty acids
Wally decides to go on a hunger strike to further one of his favorite causes. After many days with nothing but water you would expect to observe
-elevated levels of glucocorticoids -lowered blood pH -ketone bodies in his urine
The electron transport system
-receives electrons from coenzymes -produces energy that supports the synthesis of ATP -is found on the inner mitochondrial membrane (the cristae)
Cells must synthesize new organic compounds in order to
-support growth -store nutrient reserves -perform structural maintenance or repairs -produce secretions
There are ________ essential amino acids that the body either cannot synthesize or that cannot be produced in amounts sufficient for growing children.
10
Why is glucose the primary energy source for cells?
It can be efficiently stored as glycogen, which forms compact, insoluble granules
Which statement regarding the citric acid cycle is true?
Its function is to remove hydrogen atoms from organic molecules and transfer them to coenzymes
Which characteristic correctly applies to lipid metabolism?
Most lipids can be synthesized on demand
Which is a characteristic of oxidative phosphorylation?
The stepwise passage of electrons by coenzymes embedded in the cristae of the mitochondrion releases energy
Choose the correct statement regarding glycolysis.
There is a net gain of two ATP molecules for each glucose molecule
Chylomicrons:
are lipoproteins-lipid-protein complexes that contain insoluble lipids
The citric acid cycle
begins with the formation of a molecule of citric acid
Which of the following enhances the effects of glucocorticoids?
growth hormone
Identify the substance labeled "4."
hydrogen atoms
In most tissues, the transport of glucose into the cell is dependent on the presence of a carrier protein that is stimulated by which of the following?
insulin
Cells perform catabolism to generate ATP, which can be used for
muscle contraction ion transport protein synthesis glycogen synthesis
When the body is relying on internal energy reserves to continue meeting its energy demands, it is in the ________ state.
postabsorptive
The major job of coenzymes in oxidative phosphorylation includes all of the following except
the breaking of carbon-carbon covalent bonds
