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24. Nutrition, Metabolism, and Body Temperature Regulation. The majority of the food we ingest is ultimately _________. converted to fat burned to produce oxygen used to synthesize ATP stored in the stomach.
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24 Nutrition, Metabolism, and Body Temperature Regulation
The majority of the food we ingest is ultimately _________. • converted to fat • burned to produce oxygen • used to synthesize ATP • stored in the stomach
A(n) ______ nutrient is one that the body cannot synthesize rapidly enough to be useful. • regulatory • essential • endemic • caloric
It is possible for vegetarians to obtain complete proteins by combining ______ and ______. • bread; vitamins • fats; pasta • legumes; cereal grains • milk; sugar
The major metabolic function for most vitamins is that they assist enzymes by serving as _________. • sources of ATP • active sites • substrates • coenzymes
In general metabolic terms, food digestion is a form of ______, while building new protein molecules is a form of ______. • metabolism; cellular respiration • anabolism; catabolism • cellular respiration; metabolism • catabolism; anabolism
What is the true function of molecular oxygen acquired by the lungs? • O2 catalyzes the breaking of bonds in the glucose molecule. • O2 catalyzes the synthesis of ATP. • O2 serves as the final electron acceptor for the oxidation of food molecules. • O2 drives energy dependent processes in our cells.
From what process is energy derived to drive the ATP synthase enzyme in the mitochondria? • Hydrogen ions are pumped into the intermembrane space of the mitochondria. • Hydrogen ions flow down their concentration gradient through the ATP synthase enzyme into the matrix. • Hydrogen ion flow powers ATP synthase to phosphorylate ADP. • All of the above are true.
Predict what would happen to ATP production if a virus pierced holes in the inner mitochondrial membrane. • ATP production would be unchanged because the actual enzymes would not be affected. • ATP production would increase 10 times because more H+ could flow back into the matrix. • ATP production would decrease because a hydrogen ion gradient could not be established. • ATP production would decrease because the virus destroyed the ATP synthase enzymes.
Which of the following processes would be likely to occur in the skeletal muscle cells of a sprinter? • Glycolysis • Oxidative phosphorylation • The Krebs cycle • Lactic acid oxidation to pyruvic acid
Which of the following nutrients can enter the Krebs cycle? • Glucose • Amino acids • Pyruvic acid • Both b and c
Why don’t the electrons carried by NADH in the cytosol generate as many ATP as the electrons carried by NADH in the mitochondrial matrix? • There aren’t as many electrons in the cytosol. • The cytosolic electrons must be shuttled to the matrix at a loss of energy. • The cytosolic electrons are transported to a different ATP synthase that is less efficient. • They are smaller electrons.
The process whereby excess glucose is stored in cells is called ______. • glycogenesis • glycogenolysis • gluconeogenesis • glycolysis
For a marathon runner, what benefit is there to eating a diet of 75% carbohydrates and reducing the workout for 3 to 4 days before competition? • Muscle cells will increase the total amount of protein. • The extra carbohydrates are stored as fat. • The muscle cells will store higher-than-normal levels of glycogen. • The muscle cells will store higher than normal amounts of ATP.
Why isn’t it sufficient to reduce only dietary fat intake to prevent new fatty deposits from forming in the body? • Because ketone bodies form when fat intake is insufficient. • Acetyl CoA, an intermediate in glucose metabolism, is also the starting point for fatty acid synthesis. • Because muscle gets converted to fat. • Because cholesterol gets converted to fat.
Which of the following molecules is produced in the process of detoxifying harmful ammonia? • Alpha-ketoglutaric acid • Amine • Urea • Keto acids
What is the primary process by which insulin is released after ingesting a meal? • Insulin is secreted in direct response to blood glucose. • The brain sends a hormone to the pancreas to stimulate insulin release. • Insulin release is constant. • The vagus nerve innervates the pancreas and upon food ingestion fires action potentials that stimulate insulin secretion.
What is the primary objective during the postabsorptive state? • To collect and remove glucose from the blood and deposit it in cells • To convert fat to protein • To maintain blood glucose at around 70–110 mg/100 ml blood • To elevate blood glucose to the highest possible level to ensure adequate delivery to the brain
Where are the two primary sources of glucose during the postabsorptive state? • Greater omentum and subcutaneous layer • Stomach and intestine • Liver and skeletal muscle • Brain and skin
Hyperglycemic hormones include glucagon and ______. • insulin • epinephrine • GIP • aldosterone
About ______ of the body’s required cholesterol is dietary. • 50% • 85% • 15% • 100%
Why are high-density lipoproteins (HDLs) considered “good”? • The cholesterol transported by HDLs is destined for destruction. • HDLs transport cholesterol to the peripheral tissues for biosynthesis of steroid hormones. • HDLs transport cholesterol to adipose tissue. • HDLs are actually considered “bad” cholesterol.
Heat is produced internally by __________. • friction between body parts • breaking of bonds within ATP • muscle contraction • all of the above
Which of the following structures is responsible for feeding behavior? • pituitary • medulla • pons • hypothalamus
Which of the following factors is responsible for regulation of food intake? • Hormones such as leptin or NPY • Body temperature • Psychological factors • All of the above
The basal metabolic rate can most effectively be defined as the __________. • lowest point of energy used by the body • amount of energy needed to maintain life • maximal energy used by the body • energy required to digest a meal
Which of the following has the greatest effect on the BMR? • Body surface area • Muscle mass • Fitness level • Gender
Of the following heat-promoting mechanisms, which appears to be most effective in adults? • Constriction of cutaneous vessels • Shivering • Increased metabolic rate • Thyroxine secretion