Vocabulary - Nutrition, Metabolism, and Body Temperature Regulation
a substance in food used by the body to promote normal growth, maintenance, and repair.
carbohydrates, lipids, and proteins
45 / 50 molecules cannot be made fast enough to meet the body’s needs and so must be provided by the diet.
the chemical energy form used by cells.
the amount of heat energy needed to raise the temperature of 1 kilogram of water 1°C (1.8°F).
sugars used as fuel by body cells to produce ATP.
the carbohydrate molecule ultimately used as fuel by body cells to produce ATP
derived from animal products such as meat, dairy and eggs. But they are also found in some plant-based sources such as coconut, palm and palm kernel oils. These fats are solid at room temperature.
Monounsaturated fats and polyunsaturated fats are two types of unsaturated fatty acids. They are derived from vegetables and plants.
most made during food processing through partial hydrogenation of unsaturated fats.
meet all the body’s amino acid requirements for tissue maintenance and growth
protein rich but low in one or more of the essential amino acids.
important structural materials of the body, including, for example, keratin in skin, collagen and elastin in connective tissues, and muscle proteins. In addition, functional proteins such as enzymes and some hormones regulate an incredible variety of body functions.
homeostatic state in healthy adults the rate of protein synthesis equals the rate of protein breakdown and loss.
potent organic compounds needed in minute amounts for growth and good health. Unlike other organic nutrients, vitamins are not used for energy and do not serve as building blocks, but they are crucial in helping the body use those nutrients that do.
act with an enzyme to accomplish a particular chemical task.
which include B-complex vitamins and vitamin C, are absorbed along with water from the gastrointestinal tract.
Soluble Vitamins - (A, D, E, and K) bind to ingested lipids and are absorbed along with their digestion products
variety of biochemical reactions
all processes that break down complex structures to simpler ones.
all reactions in which larger molecules or structures are built from smaller ones
(catabolic) food fuels, particularly glucose, are broken down in cells and some of the energy released is captured to form ATP, the cells’ energy currency.
primes the molecule to change in a way that increases its activity, produces motion, or does work.
the gain of oxygen or the loss of hydrogen
substances gain energy
reduction reactions – REDOX , “oxidized” substances lose energy and “reduced” substances gain energy as energy-rich electrons are transferred from one substance to the next
Enzymes that catalyze redox reactions in which hydrogen atoms are removed
Enzymes catalyzing the transfer of oxygen
level phosphorylation - occurs when high-energy phosphate groups are transferred directly from phosphorylated substrates (metabolic intermediates such as glyceraldehyde phosphate) to ADP
much more complicated, but it also releases most of the energy that is eventually captured in ATP bonds during cellular respiration.
couple the movement of substances across membranes to chemical reactions
anaerobic process occurs in the cytosol of cells. This pathway is a series of ten chemical steps by which glucose is converted to two pyruvic acid molecules.
in the absence of oxygen two hydrogen atoms added to pyruvic acid.
the oxygenrequiring Krebs cycle and electron transport chain within the mitochondria
The Krebs cycle
second stage of glycolysis, which occurs in the mitochondrial matrix, is fueled largely by pyruvic acid produced during glycolysis and by fatty acids resulting from fat breakdown.
electron transport chain
which carries out the final catabolic reactions
areas of the membrane freely permeable to H+ are at large enzyme-protein complexes (complex V).
a process that forms glycogen from glucose when high cellular ATP begins to inhibit glycolysis.
a process that breaks down glycogen to glucose when blood glucose levels begin to fall.
a process that forms glucose from nonglucose molecules to maintain blood glucose when dietary sources and glucose reserves begin to be depleted.
a process used to store excess glycerol and fatty acids in adipose tissue as triglycerides.
the breakdown of stored fats into glycerol and fatty acids, is essentially lipogenesis in reverse
three water-soluble compounds that are produced as by-products when fatty acids are broken down for energy in the liver.
Transfer of an amine group from an amino acid to -ketoglutaric acid, thereby transforming -ketoglutaric acid to glutamic acid
Removal of an amine group from glutamic acid as ammonia and regeneration of -ketoglutaric acid (NH3 is converted to urea by the liver)
Amino Acid Pool
the body’s total supply of free amino acids
the time during and shortly after eating, when nutrients are flushing into the blood from the gastrointestinal tract.
directs essentially all events of the absorptive state
fasting state, is the period when the GI tract is empty and energy sources are supplied by the breakdown of body reserves.
The increased use of noncarbohydrate fuel molecules (especially triglycerides) to conserve glucose
promotes a rise in blood glucose levels
serves instead as the structural basis of bile salts, steroid hormones, and vitamin D and as a major component of plasma membranes. Additionally, cholesterol is part of a key signaling molecule (the hedgehog protein) that helps direct embryonic development. About 15% of blood cholesterol comes from the diet. The other 85% is made from acetyl CoA by the liver
triglycerides and cholesterol transport, solubilize the hydrophobic lipids, and the protein part of the complexes contains signals that regulate lipid entry and exit at specific target cells. Lipoproteins vary considerably in their relative fat-protein composition, but they all contain triglycerides, phospholipids, and cholesterol in addition to protein, the higher the percentage of lipid in the lipoprotein, the lower its density; and the greater the proportion of protein, the higher its density.
very low density lipoprotein
“healthy” oils that have been hardened by hydrogenation to make them more solid. Trans fats cause serum changes worse than those caused by saturated fats. The trans fatty acids spark a greater increase in LDLs and a greater reduction in HDLs, producing the unhealthiest ratio of total cholesterol to HDL.
the energy liberated during food oxidation.
includes energy immediately lost as heat (about 60% of the total), used to do work (driven by ATP), and stored as fat or glycogen.
Body Mass Index (BMI)
The official medical measure of obesity and body fatness is the, an index of a person’s weight relative to height. To estimate BMI, multiply weight in pounds by 705 and then divide by your height in inches squared: BMI = wt(lb) X 705/ht(inches)2
including insulin and cholecystokinin (CCK) released during food absorption, act as satiety signals to depress hunger
secreted exclusively by adipose cells in response to an increase in body fat mass and it serves as an indicator of the body’s total energy stores in fat tissue. FAT-O-STAT
The body’s rate of energy output
Basal Metabolic Rate
reflects the amount of energy required for performance of only the essential activities of the body, and is expressed as kilocalories per square meter of body surface area
produced by the thyroid gland is probably the most important hormonal factor in determining BMR.
Total Metabolic Rate (TMR)
the rate of kilocalorie consumption needed to fuel all ongoing activities—involuntary and voluntary.
Induced Thermogenesis - Food ingestion also induces a rapid increase in TMR.
Body Core Temperature
(organs within the skull and the thoracic and abdominal cavities) has the highest temperature
Body shell Temperature
(essentially the skin) has the lowest temperature
the loss of heat in the form of infrared waves (thermal energy). Any object that is warmer than objects in its environment—for example, a radiator and (usually) the body—will transfer heat to those objects
the transfer of heat from a warmer object to a cooler one when the two are in direct contact with each other.
the process that occurs because warm air expands and rises and cool air, being denser, falls
Water evaporates because its molecules absorb heat from the environment and become energetic enough—in other words, vibrate fast enough—to escape as a gas, which we know as water vapor.
heat absorbed by water during evaporation
Insensible Water Loss
The unnoticeable water loss occurring due to the continuous evaporation of water from the lungs, from the oral mucosa, and through the skin.
Insensible Heat Loss
The unnoticeable Heat loss occurring due to the continuous evaporation of water from the lungs, from the oral mucosa, and through the skin.
involuntary shuddering contractions, is triggered when brain centers controlling muscle tone are activated and muscle tone reaches sufficient levels to alternately stimulate stretch receptors in antagonistic muscles. Shivering is very effective in increasing body temperature because muscle activity produces large amounts of heat.
elevated body temperature resulting from prolonged uncontrolled exposure hot and humid environment
low body temperature resulting from prolonged uncontrolled exposure to cold
controlled hyperthermia. Most often, it results from infection somewhere in the body, but it may be caused by cancer, allergic reactions, or CNS injuries. Whatever the cause, macrophages and other cells release cytokines, originally called pyrogens (literally, “fire starters”)
A desire for food. A psychological phenomenon dependent on memory and associations, as opposed to hunger, which is a physiological need to eat
Vitamin B1 (thiamine)
•Found in Lean meats, liver, legumes, peanuts, whole grains
•Coenzyme used in removing CO2 from organic compounds; required for synthesis of acetylcholine and pentose sugars
•Deficiency - Beriberi (nerve disorders, emaciation, anemia), profound fatigue
Vitamin B2 (riboflavin)
•Milk, liver, yeast, meats, enriched grains, vegetables
•Component of coenzymes FAD and FMN
•Deficiency - Dermatitis, skin lesions such as cracks at corners of mouth, blurred vision None known
Vitamin B3 (niacin)
•Nuts, poultry, fish, meats, grains
•Component of coenzyme NAD
•Deficiency - Pellagra, skin and gastrointestinal lesions, nervous disorders
•Excess - Liver damage, gout, hyperglycemia
Vitamin B5 (pantothenic acid)
•Most foods: meats, dairy products, whole grains, etc.
•Component of coenzyme A; involved in synthesis of steroids and hemoglobin
•Deficiency - Fatigue, numbness, tingling of hands and feet, neuropathy of alcoholism
Vitamin B6 (pyridoxine)
•Meats, fish, poultry, vegetables, bananas
•Coenzyme used in amino acid metabolism; required for glycogenolysis and antibody formation
•Deficiency - Irritability, convulsions, muscular twitching, anemia
•Excess - Unstable gait, numb feet, poor coordination, depressed deep tendon reflexes, nerve damage
Vitamin B9 (folic acid or folacin)
•Liver, oranges, nuts, legumes, whole grains
•Coenzyme in nucleic acid and amino acid metabolism; needed for normal neural tube development in embryos
•Deficiency - Anemia, gastrointestinal problems, spina bifida risk in newborns, neural deficits May mask signs of vitamin
•Excess - B12 deficiency while allowing its neurological damage
Vitamin B12 (cyanocobalamin)
•Meats, eggs, dairy products except butter (not found in plant foods) (also made by enteric bacteria)
•Coenzyme in nucleic acid metabolism; maturation of red blood cells
•Deficiency - Pernicious anemia, nervous system disorders (typically due to impaired absorption)
•Legumes, other vegetables, meats, liver, egg yolk
•Coenzyme in synthesis of fat, glycogen, and amino acids
•Deficiency - Scaly skin, pallor, fatigue, neuromuscular disorders, elevated cholesterol levels
Vitamin C (ascorbic acid)
•Fruits and vegetables, especially citrus fruits, strawberries, broccoli, cabbage, tomatoes, green peppers
•Used in collagen synthesis (such as for bone, cartilage, gums); antioxidant; aids in detoxification; improves iron absorption
•Deficiency - Scurvy (degeneration of skin, teeth, blood vessels), weakness, delayed wound healing, impaired
•Excess - immunity Gastrointestinal upset, kidney stone formation, gout
Vitamin A (retinol)
•Provitamin A (betacarotene) in deep green and orange vegetables and fruits; retinol in dairy products
•Component of visual pigments; maintenance of epithelial tissues; antioxidant; helps prevent damage to cell membranes
•Deficiency - Night blindness; dry, scaling skin; increased infection
•Excess - Headache, irritability, vomiting, hair loss, blurred vision, liver and bone damage
Vitamin D (antirachitic factor)
•(twice that amount for African Americans) Dairy products, egg yolk (also made in human skin in presence of sunlight)
•Functionally a hormone; aids in absorption and use of calcium and phosphorus; promotes bone growth
•Deficiency - Rickets (bone deformities) in children, bone softening (osteomalacia) in adults, poor muscle tone, joint pain, enhanced vulnerability to infections, increased cancer risk
•Excess - Brain, cardiovascular, and kidney damage, calcification of soft tissues, fatigue, weight loss,
Vitamin E (tocopherol)
•Wheat germ, vegetableoils, nuts, seeds, dark green leafy vegetables
•Antioxidant; helps prevent atherosclerosis and damage to cell membranes
•Deficiency - Possibly anemia S
•Excess - ow wound healing, increased clotting time
Vitamin K (phylloquinone)
•Green vegetables, tea (also made by enteric bacteria)
•Important in formation of blood clotting proteins; intermediate in electron transport chain
•Deficiency - blood clotting; bruising
•Excess - Liver damage and anemia
•Dairy products, dark green vegetables, legumes
•Bone and tooth formation, blood clotting, nerve and muscle function
•Deficiency - Stunted growth, possibly loss of bone mass
•Excess - Depressed neural function, muscle weakness, calcium deposit in soft tissues
Phosphorus (P) 700 Dairy products, meats,
•whole grains, nuts
•Bone and tooth formation, acid-base balance, nucleic acid synthesis
•Deficiency - Weakness, loss of minerals from bone, rickets
•Sulfur-containing proteins from many sources (meats, milk, eggs)
•Component of certain amino acids
•Deficiency - Symptoms of protein deficiency
•Meats, dairy products, many fruits and vegetables, grains
•Acid-base balance, water balance, nerve function, muscle contraction
•Deficiency - Muscular weakness, paralysis
•Excess - Muscular weakness, cardiac problems, alkalosis
•Table salt, cured meats (ham)
•Osmotic pressure, acidbase balance, gastric juice formation
•Muscle cramps, reduced appetite
•Table salt, cured meats
•Osmotic pressure, acid-base balance, water-balance, nerve function, important for pumping glucose and other nutrients
•Deficiency - Muscle cramps, reduced appetite
•Excess - Hypertension, edema
•Whole grains, green leafy vegetables
•Component of certain coenzymes in ATP formation
•Deficiency - Nervous system disturbances, tremors, muscle weakness, hypertension, sudden cardiac death
•Excess - Diarrhea