Chapter 23 A&P

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name the heat conservation mechanism that conducts heat from deep arteries to adjacent deep in the limbs

countercurrent exchange is the heat conservation mechanism that results in the conduction of heat from deep arteries to adjacent deep veins of the limbs.

compare glycogenesis and glycogenolysis

glycogenesis is the formation of glycogen from glucose. glycogeneolysis is the breakdown of glycogen to glucose

distinguish between a complete protein and an incomplete protein

a complete protein meets the body's amino acid requirements; an incomplete protein is deficient in one or more of the essential amino acids

whys is digestion important

digestion is important because cells throughout the body rely on the organic molecules from the food we eat, produce energy and to replenish the intracellular nutrient pool

identify the fates of fatty acids

fatty acids may become a source of energy or a component of triglycerides, glycolipids, phospholipids, prostaglandins, cholesterol and steroids

describe the source of intestinal gas

intestinal gas, or flatus is generated by bacterial activities in the colon when indigestible carbohydrates stimulate bacterial gas production

when and how do ketone bodies form

ketone bodies form during the post absorptive state, when lipids and amino acids are broken down in the liver. the increase concentration of acetyl-CoA that results from their breakdown forms ketone bodies. ketone bodies are not catabolized by liver cells and they diffuse into the circulation.

how might a lack of neuropeptide Y in the hypothalamus affects the control of appetite.

lack of neuropeptide Y a hypothalamic neurotransmitter would probably decrease appetite because it normally stimulates the feeding center

describe leptin and its effect on appetite

leptin is a peptide hormone produced by adipose tissue during the synthesis of triglycerides. it stimulates the satiety center and suppressed appetite

explain the process of metabolic turnover

metabolic turnover is the process in which cells continuously replace their cellular components

most of the absorbed nutrients enter into which blood vessel

most nutrients enter into a branch of the hepatic portal vein and are transported to the liver

describe the role of nonshivering thermogenesis in regulation body temperature

nonshivering thermogenesis involves the release of hormones that increase the metabolic activity of all tissues resulting in an increase in body temperature

compare oxidation and reduction

oxidation is a gain of oxygen or loss of hydrogen or electrons form an atom or molecule. reduction is the loss of oxygen or gain of hydrogen or electrons to an atom or molecule

define oxidative phosphorylation

oxidative phosphorylation is the generation of ATP as the result of the transfer of electrons from coenzyme NADH and FADH2 to oxygen by a sequence of electron carries within mitochondria

briefly describe phenylketonuria (PKU)

phenylketonuria is an inherited metabolic disorder resulting from an inability to convert phenylalanine to tyrosine

define protein deficiency disease and cite an example

protein deficiency disease are nutritional disorders resulting from a lack of one or more essential amino acids. Kwashiorkor is an example of a protein deficiency disease.

what heat transfer process accounts for about 1/2 of a persons heat loss when indoors

radiation accounts for about 1/2 of a persons heat loss indoors

in amino acid metabolism, identify the processes by which the amino acid group is removed

the amino group is removed by deamination or transamination

what happens to the ammonium ions that are removed from amino acids during deamination

the ammonium ion combine with carbon dioxide to form urea which is ultimately excreted in the urine

list the products of glycolysis

2 molecules each of pyruvate, ATP and NADH

describe the roles of LDL's and HDL's

LDL's deliver cholesterol to body tissue. HDL absorb unused cholesterol form body tissues returning it to the liver, where it may be packed into new LDL or excreted with bole salts in bile.

what two coenzymes transfer hydrogen atoms to the electron transport chain

NAd and FAD transfer hydrogen atoms to the electron transport chain

define a balanced diet

a balanced diet contains all the ingredients needed to maintain homeostasis and prevent malnutrition

what is basal metabolic rate

basal metabolic rate is the minimum resting energy expenditure of an awake, alter person

define beta-oxidation

beta-oxidation is a fatty acid catabolism that produces molecules of acetyl-CoA

explain why carbohydrates are preferred over proteins and lipids as an energy source

carbohydrates are the preferred energy source because proteins and lipids are more important as structural components of cells and tissues

compare catabolism and anabolism

catabolism is the breakdown of large molecules into smaller ones, whereas anabolism converts small molecules into larger ones

when do cells make new compounds

cells make a new compound to maintain and repair structures to support growth, and to build up nutrient reserves

how do the absorptive and postabsorptive states maintain normal blood glucose levels.

during the absorptive state, insulin prevents a large surge in blood glucose after a meal by stimulating the liver to remove glucose from the circulation. during postabsorptive state, blood glucose begins to decrease triggering the release of glucagon which stimulates the liver to release glucose into the circulation

identify and briefly define two eating disorders

eating disorders are psychological problems that result in inadequate food consumption or excessive food consumption followed by purging

define energetics

energetics is the study of the flow of energy and its change from one form to another

what is the difference between a micelle and chylomicron

micelles are lipids- bile salt complexes (containing fatty acids, glycerol, and monoglycerides) formed in the intestinal lumen. chylomicrons are lipoproteins formed in intestinal epithelial cells and contain newly synthesized triglycerides cholesterol and other lipids surrounded by phospholipids and proteins

Identify when most of the CO2 is released during the complete catabolism of glucose

most (2/3) of the CO2 release is the complete catabolism of glucose occurs during the citric acid cycle

where does most nutrient absorption occur

most nutrient absorption occurs in the small intestine primarily in the jejunum

define nutrition

nutrition is the absorption of nutrients from food

define and describe the absorptive state

the absorptive state, lasting about 4 hours, is the period following a meal when nutrient absorption is underway. during this time insulin stimulates glucose uptake and glycogenesis amino acid uptake and protein synthesis. androgens, estrogens and growth hormone stimulate protein synthesis. glycolysis and aerobic metabolism provide the necessary ATP

list the reactants required and products generated by mitochondria

the reactants required by mitochondria are continuous supply of 2-carbon substrates and O2's the mitochondria products are CO2, H2O and ATP

identify the two classes of vitamins

the two classes of vitamins are fat-soluble vitamins and water soluble vitamins

predict the effect of peripheral vasodilation on a persons body temperature.

the vasodilation of peripheral vessels would increase blood flow to the skin and thus the amount heat the body can lose. as a result, body temperature would decrease

define thermoregulation

thermoregulation is the hemostatic control of body temperature

if vitamins do not provide a source of energy, what is their role in nutrition

vitamins play an important role in metabolic pathways by serving as coenzymes

which molecule is a key reactant in both ATP production from fatty acids and lipogenesis

acetyl-CoA is a reactant molecule in ATP production and in the synthesis of most types of lipids

how is heat loss different between conduction and convection

conduction is the direct transfer of heat through physical contact. convection is heat loss to the cooler air in contact with the skin. the air warmed by the skin rise and it is repeatedly replaced by cooler air until there is no difference in temperature

which hormone inhibits the satiety center and stimulates appetite in the short term

ghrelin, a hormone secreted by the gastric mucosa when the stomach is not full, inhibits the satiety center and stimulates appetite

explain the role of glycogen in cellular metabolism

glycogen is synthesized form excess glucose molecules by liver and muscle cells, and it serves as an intracellular glucose reserve

explain when glycolysis is important in cellular metabolism

glycolysis is important when ATP must be produced anaerobically, for example during peak levels of physical activity, at all times in red blood cells, or when a tissue temporarily deprived of oxygen

describe the role that hydrogen ion channels play in the generation of ATP

hydrogen ion channels are the passageway for the diffusion of hydrogen ions from the inner membrane space of the mitochondria to the matrix. this movement of hydrogen ions power the production of ATP by ATP synthase

define insensible perspiration

insensible perspiration is the evaporation of water from the skin and alveolar surface of the lungs

define the role of CCK release and its effects on proteins

the arrival of acidic chyme in the duodenum triggers the release of CCK which stimulates the production and release of inactive pancreatic proenzymes. enteroipeptides released from the duodenum converts the pancreatic proenzyme trypsinogen into the proteolytic enzyme trypsin. trypsin then converts other proenzymes to yield chymotrypsin, carboxypeptidase and elastase. each of these enzymes attacks peptide bonds that link specific amino acids while ignoring others. as a result they break down proteins into a mixture of dipeptides, tripeptides and amino acids

of these- carbohydrates, lipids or proteins- which releases the greatest amount of energy per gram during catabolism

the catabolism of lipids release the greatest amount of energy per gram

briefly describe the citric acid cycle, and explain its role

the citric acid cycle is the reaction sequence that occurs in the matrix of mitochondria. in the process organic molecules are broken down, carbon dioxide molecules are released, and hydrogen atoms are transferred to coenzymes that deliver them to the electron transport chain

what molecule forms the common substrate for the citric acid cycle

the common substrate for the citric acid cycle in the mitochondria is the 2-carbon acetate ion, CH3COO-, which is attached to coenzyme A to form acetyl-CoA

what does the liver do when the chylomicrons it receives

the liver absorbs chylomicrons, removes the triglycerides, combines the cholesterol from the chylomicron with recycled cholesterol and alters the surface proteins. newly synthesized complexes are released into the bloodstream as low density lipoproteins (LDL) or very low density lipoproteins (VLDL)


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