26 terms

Metabolism 2

absorptive state
time during and shortly and after when nutrients are flushing into the blood from the gastrointestinal state.
postabsorptive state
of fasting state, is the period when the GI tract is empty and energy sources are supplied by the breakdown of body reserves.
directs essentially all events of the absorptive state.
diabetes mellitus
a consequence of inadequate insulin production or abnormal insulin receptors.
glucose sparing
the increased use of noncarbohydrate fuel molecules (especially tricglycerides) to conserve glucose.
an insulin antagonist that is released when the alpha cells of the pancreatic islets are stimulated due to a decline in glucose levels.
though an important dietary lipid, has received little attention in this discussion so far, primarily because it is not used as an energy source. it serves instead as the structural basis of bile salts, steroid hormones, and vitamin D and as a major component of plasma membranes.
high density lipoprotein (HDL)
They are particularly rich in phospholipids and cholesterol. They scoop up and transport excess cholesterol from peripheral tissues to the liver, where it is broken down and becomes part of bile,
Low density lipoprotein (LDL)
regulate cholesterol synthesis in the tissue cells, docking of LDL to the LDL receptor triggers receptor-mediated endocytosis of the entire particle.
very low density lipoprotein (VLDL)
Liver is the primary source. they transport triglycerides from the liver to the peripheral tissues mostly to adipose tissues.
trans fat
"healthy" oils that have been hardened by hydrogenation to make them more solid. they cause serum changes worse than those caused by saturated fats.
energy intake
the energy liberated during food oxidation.
energy output
includes energy (1) immediately lost as heat (about 60% of the total), (2) used to do work (driven by ATP) and (3) stored as fat or glycogen. Because losses of organic molecules in urine, feces, and perspiration are very small in healthy people, they are usually ignored in calculating energy output.
a key component of the long-term controls of feeding behavior. Its a hormone
metabolic rate
the bodies rate of energy output.
basal metabolic rate
reflects the energy the body needs to perform only its most essential activities, such as breathing, and maintaining resting levels of organ function.
the amount of _______ produced by the thyroid gland is probably the most important hormonal factor in determining BMR. It has been dubbed the "metabolic hormone". Its direct effect on most body cells is to increase O2 consumption and heat production, presumably by accelerating the use of ATP to operate sodium-potassium pump.
causes a host of problems resulting from the excessive BMR it produces. The body catabolizes stroed fats and tissue proteins and despite increased hunger and food intake, the person often loses weight.
results in slowed metabolism, obesity, and diminished thought process.
total metabolic rate
the rte of kilocalorie consumption needed to fuel all ongoing activities-involuntary and voluntary.
food-induced thermogenesis
greatest when proteins are eaten. where food ingestion induces a rapid increse in TMR.
phenylkentonuria (PKU)
a disease where the tissue cells are unable to use the amino acid phenylalanine, which is present in all protein foods. the defect involves a deficiency of the enzyme that converts phenylalanine to tyrosine.
non-insulin dependent diabetes
by middle age and particularly old age, it becomes a major problem, particularly in people who are obese.
a desire for food, a psychological phenomenon dependent on memory and associations, as opposed to hunger, which is a physiological need to eat.
familial hypercholesteremia
an inherited condition in which the LDL receptors are absent or abnormal, the uptake of cholesterol by tissue cells is blocked, and the total concentration of cholesterol (and LDLS) in the blood is enormously elevated.
skin-fold test
clinical test of body fatness. a skin fold in the back of the arm or below the scapula is measured with a caliper, A fold over 1 inch in thickness indicates excess fat. also called the fat fold test.