Chapter 25: Metabolism
What lipoproteins transport cholesterol to cells of the body?
LDL
Why are minerals, vitamins, and water classified as essential nutrients?
The body cannot synthesize these nutrients in sufficient quantities.
The breakdown of fatty acid molecules results in the production of __________.
acetyl coenzyme A
The transition between glycolysis and the TCA cycle involves a molecule called __________.
acetyl coenzyme A
Catabolizing fatty acids by beta-oxidation results in the formation of what product?
acetyl-coA
The process in which fatty acids are broken down into two-carbon fragments is __________.
beta oxidation
The actual process of ATP formation associated with the electron transport system is called __________.
chemiosmosis
Which lipoprotein carries dietary triglycerides to the liver?
chylomicrons
The first step in a sequence of enzymatic reactions in the tricarboxylic acid cycle is the formation of __________.
citric acid
What is the term for the direct transfer of heat energy through physical contact?
conduction
Which of the following is a nitrogen compound that is important for energy storage in muscle tissue?
creatine
If the cells are catabolizing an amino acid for its energy, what is the first step in amino acid catabolism?
deamination
The mechanism of heat loss that involves the skin and lung alveoli is _______________.
evaporation
In resting skeletal muscles, a significant portion of their metabolic demand is met through the __________.
fatty acids
What is the primary focus of nutritional processing in the postabsorptive state?
maintaining blood glucose levels
Where in the cell does the citric acid cycle occur?
mitochondrial matrix
A cell with excess carbohydrates, lipids, and amino acids will break down carbohydrates in order to __________.
obtain energy
If excess glucose remains in the blood circulation after glycogen formation, the hepatocytes use the glucose to __________.
synthesize triglycerides
What is the vitamin that functions as a coenzyme in the deamination process?
vitamin B6
Oxidative phosphorylation produces __________ percent of the ATP in our cells.
90
The breakdown of food results in:
carbon dioxide, water, and energy
When blood glucose concentrations are elevated, the glucose molecules are __________.
catabolized for energy
Which process in the metabolism of glucose is NOT part of aerobic metabolism?
glycolysis
Which of the following is an important energy source during periods of starvation, when glucose supplies are limited?
free fatty acids
Glucose levels are maintained during starvation through the process called:
gluconeogenesis
Which process in the aerobic metabolism of glucose takes place in the cytosol?
glycolysis
During open-heart surgery, which of the following thermoregulatory changes is induced in the patient's body?
hypothermia
What is the effect of androgens and estrogens on general peripheral tissues?
increased amino acid use in protein synthesis
Where in the cell does the electron transport system occur?
inner mitochondrial membrane
Some amino acids can be used to make ATP because they can be converted to __________.
pyruvic acid and acetyl coA
All nutrients can be used by the mitochondria to provide energy. In what form are these nutrients "fed" into the mitochondria?
two-carbon fragments
Amino acids are deaminated and the amine group is ultimately excreted as __________.
urea
The cycle in the liver that detoxifies ammonia is called the:
urea cycle