Metabolism!
________ is a substance in food used by the body to promote normal growth, maintenance, and repair.
A nutrient
Which of the following is not a characteristic of glycolysis?
Glycolysis is an aerobic process
______ is considered "good" cholesterol; high blood levels of this cholesterol are thought to be beneficial
HDLs
Select the correct statement about proteins.
Proteins will be used by most cells for ATP synthesis if insufficient carbohydrates are ingested.
Cholesterol
Serves as a precursor to hormones and maintains the fluidity of the plasma membrane
Which of the following is a characteristic of the electron transport chain (ETC)?
The ETC occurs in the mitochondria.
Which of the following is a characteristic of the Krebs cycle?
The Krebs cycle generates a rich supply of the reduced coenzymes, NADH and FADH2
Which of the following statements is a false or incorrect statement?
The amino acid pool is the body's total supply of amino acids in the body's proteins.
Glycogenolysis
The cleavage of glycogen to release glucose
Glycogenesis
The formation of glycogen to store glucose
Gluconeogenesis
The process of forming new glucose from noncarbohydrate molecules
Beta oxidation
The start phase of fatty acid breakdown
Lipogenesis
Triglyceride synthesis
Fat-soluble vitamins can be toxic if consumed in large quantities
True
The body is able to form glucose from noncarbohydrate precursors
True
Protein
Used to build enzymes
Which of the following is a water-soluble vitamin?
Vitamin B
Which of the choices below is not a source of glucose during the postabsorptive state?
absorption of glucose from the GI tract
Glycogen is formed in the liver during the ________.
absorptive state
In the liver, the amine group of glutamic acid is removed as ________ in the oxidative state.
ammonia
As proteins are broken down for energy______ is generated; the liver then converts this potentially toxic intermediate into______.
ammonia; urea
Redox reactions:
are characterized by one substance gaining an electron while another substance loses an electron.
Conversion of fatty acids into acetyl groups.
beta oxidation
The term metabolism is best defined as ________.
biochemical reactions involved in building cell molecules or breaking down molecules for energy
As the body progresses from the absorptive to the postabsorptive state, only the ________ continues to burn glucose while every other organ in the body mostly switches to fatty acids
brain
The primary function of cellular respiration is to ________.
break down food molecules and generate ATP
Catabolism would be best described as a process that ________.
breaks down complex structures to simpler ones
Lipogenesis occurs when ________.
cellular ATP and glucose levels are high
Prostaglandins play a role in ________.
control of blood pressure
Glycolysis is best defined as a catabolic reaction based upon the ________.
conversion of glucose into two molecules of pyruvic acid
Which of the choices below is not a fate of carbohydrate taken into the body?
conversion to a nucleic acid
Glycolysis occurs in the ______ of cells and is an _______ process.
cytosol; anaerobic
Oxidation-reduction reactions are catalyzed by which of the following enzymes?
dehydrogenases and oxidases
Which of the following food groups are considered good sources of complete proteins?
eggs, milk, yogurt, meat, and fish
The term metabolic rate reflects the ________.
energy the body needs to perform only its most essential activities
Conditions that promote the oxidative deamination and energy use of amino acids include ________.
excessive amounts of protein in the diet
Which of the following nutrients yield the highest amount of energy per gram when metabolized?
fats
When ketone bodies are present in the blood and urine in large amounts, it usually indicates increased metabolism of ________.
fatty acids
Formation of glucose from proteins or fats.
gluconeogenesis
Neurons and red blood cells rely exclusively on ________ to meet their energy needs.
glucose
The molecule that serves as the major source of readily available fuel for neurons and blood cells is ________.
glucose
Gluconeogenesis is the process in which ________.
glucose is formed from noncarbohydrate precursors
Which of the following molecules are considered key molecules at metabolic crossroads?
glucose-6-phosphate, pyruvic acid, acetyl CoA
In gluconeogenesis, during the postabsorptive state, amino acids and ________ are converted to glucose.
glycerol
In the postabsorptive state
glycogen is broken down to release glucose
Storage of glucose in the form of glycogen
glycogenesis
Breakdown of glycogen to release glucose
glycogenolysis
Glucose can be obtained from ________.
glycogenolysis
Breakdown of glucose to pyruvic acid.
glycolysis
Which of the following does not occur in the mitochondria?
glycolysis
Which of the choices below describes the pathway of cellular respiration (the complete oxidation of glucose)?
glycolysis, Krebs cycle, electron transport chain, oxidative phosphorylation
Dietary fats are important because they ________.
help the body absorb fat-soluble vitamins
Which hormone directs essentially all the events of the absorptive state?
insulin
In the absorptive state
insulin serves as the regulatory hormone.
Cholesterol, though it is not an energy molecule, has importance in the body because it ________.
is a stabilizing component of the plasma membranes and is the parent molecule of steroid hormones
Formation of ketone bodies.
ketogenesis
Anabolism includes reactions in which ________.
larger molecules or structures are built from smaller ones
Synthesis of lipids from glucose or amino acids.
lipogenesis
Splitting of triglycerides into glycerol and fatty acids
lipolysis
The process of breaking triglycerides down into glycerol and fatty acids is known as ________.
lipolysis
Oxidative deamination takes place in the ________.
liver
The primary goal during the postabsorptive state is to:
maintain blood glucose levels within a homeostatic range.
Oxidation reduction reactions ________.
may involve the loss of hydrogen and electrons
What is the outcome of ketosis?
metabolic acidosis
It is important to ensure that your diet is adequately rich in vitamins because ________
most vitamins are coenzymes needed to help the body utilize essential nutrients
The primary reason elderly people should decrease their caloric intake is that ________.
muscle mass and metabolism decline with age
Which of the following statements best describes complete protein?
must meet all the body's amino acid requirements for maintenance and growth
person who is starving is likely to exhibit:
negative nitrogen balance
Which of the following mechanisms produces the most ATP during cellular respiration?
oxidative phosphorylation
What process primes a molecule to change in a way that increases its activity, produces motion, or does work?
phosphorylation
In the case of a person who consumes a normal, balanced diet, proteins are essential to the body for all of the following except ________.
production of energy
Which of the following is the most important function of the liver?
protein metabolism
Loss of heat in the form of infrared waves is termed ________.
radiation
Which of the following is a normal consequence of the activation of the heat-promoting center?
release of epinephrine
When a person's hypothalamic thermostat is set to a higher level and the actual body temperature is below that level, the person may ________
shiver
Which of the choices below is not a major route of heat exchange?
shivering
Which of the choices below is not a mechanism of heat production?
sweating
Vitamins
Can function as coenzymes
_____ refers to reactions in which large molecules are broken down into smaller molecules.
Catabolism
Which of the following is an example of catabolism?
Cellular respiration
Which of the following is not an end product of the Krebs cycle?
Citric acid
A growing child is likely to exhibit negative nitrogen balance.
False
A substance that is reduced has lost an electron
False
Leptin is a short-term regulator of food intake.
False
Most ATP in cellular respiration is generated in glycolysis.
False
The body's overall rate of energy output is called the basal metabolic rate.
False
Glucose serves as the initial reactant.
Glycolysis
Occurs in the cytosol of a cell
Glycolysis
Mineral
An example is calcium
Which of the choices below happens during the absorptive state?
Anabolic processes exceed catabolic ones
Which of the following would raise body temperature?
Eating a large meal
Glucose
Exclusive energy source for neurons
_________ is the key hormone regulator of the absorptive state.
Insulin
Which of the following is not true of beta oxidation?
It involves the anabolism of fats.
Involves the removal of hydrogen electrons and CO2 from the substrate molecule.
Krebs cycle and electron transport chain
Produces the most ATP
Krebs cycle and electron transport chain
Involves the use of oxygen to pick up excess hydrogen and electrons.
Krebs cycle and electron transport chain.
______ are considered "bad" cholesterol; high blood levels are believed to increase the risk for cardiovascular disease.
LDLs
The final electron acceptor in the electron transport chain is _____.
O2
Which of the following best defines negative nitrogen balance?
Protein breakdown exceeds protein synthesis.
Many factors influence BMR. What is the most critical factor?
the ratio of surface area to volume (weight) of the body
The amount of ________ produced is probably the most important hormonal factor in determining BMR.
thyroxine
The body's rate of kilocalorie consumption needed to fuel all ongoing activities is called the:
total metabolic rate.
Transamination is the process whereby the amine group of an amino acid is ________.
transferred to a keto acid
Which of the following is not a function of LDLs?
transport cholesterol from the peripheral tissues to the liver
The most abundant dietary lipids are ________.
triglycerides
When proteins undergo deamination, the waste substance found in the urine is mostly________
urea
Ammonia, which is a byproduct of protein metabolism, is converted to _____ in the ______.
urea; liver
Heat-loss mechanisms do not include ________.
vasoconstriction of peripheral blood vessels