Anatomy: Chapter 23

Distinguish between catabolism and anabolism

-Catabolism-breakdown of organic substrates in the body, -anabolism-synthesis of new organic molecules

Describe the roles of LDL and HDL

-LDL- deliver cholesterol to body tissues, -HDL- absorb unused cholesterol from body tissues, returning it to the liver where it may be packaged into new LDLs or excreted with bile salts in bile

Distinguish between a complete protein and an incomplete protein

-complete protein- meets the body's amino acid requirement -incomplete protein- deficient in one or more of the essential amino acids

What hormone inhibits the satiety center and stimulates appetite in the short term?

Ghrelin

What heat transfer process accounts for about 1/2 of a person's heat loss while indoors?

Radiation

How might a lack of neruopeptide Y in the hypothalamus affect the control of appetite?

a 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

a peptide hormone produced by adipose tissue during the synthesis of triglycerides. -It stimulates the satiety center and suppresses appetite.

Define nutrition

absorption of nutrients from food

Define absorptive state and post absorptive state

absorptive-lasting about 4 hours, time following a meal when nutrient absorption is underway postabsorptive-GI tract is empty of nutrients and body's own stores must supply energy

Identify the processes by which the amino group is removed

deamination or transamination.

explain when glycolysis is important in cellular metabolism

during peak levels of physical activity, in RBC, or when tissue is temporarily deprived of oxygen

Identify the two classes of vitamins

fat-soluble vitamins and water-soluble vitamins

Describe the source of intestinal gas

generated by bacterial activities in the colon when indigestible carbohydrates stimulate bacterial gas production

Describe the role of nonshivering thermogenesis in regulating body temperature

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

When and how do ketone bodies form?

-form during the post absorptive state when lipids and amino acids are broken down in the liver. -The increased concentration of acetyl-CoA that results from their breakdown forms ketone bodies. -they diffuse into the circulation.

Briefly describe phenylketonuria (PKU)

-inherited metabolic disorder resulting from an inability to convert phenylalanine to tyrosine

Identify and briefly define two eating disorders

-psychological problems that result in inadequate food consumption (anorexia nervosa) or excessive food consumption followed by purging (bulimia).

List the products of glycolysis

2 ATP, 2 NADH, 2 pyruvate

What molecule forms the common substrate for the citric acid cycle?

2-carbon molecule of acetate

Define protein deficiency disease

nutritional disorders resulting from a lack of one or more essential amino acids

compare oxidation and reduction

oxidation: gain of oxygen and loss of a molecule, atom, or ion reduction: loss of oxygen and gain of electrons by a molecule, atom, or ion

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

preferred because proteins and lipids are more important as structural components of cells and tissues

list the reactants required and products generated by mitochondria

required- 2-carbon substrates products- ATP, H20, CO2

Where does most nutrient absorption occur?

small intestine- jejunum

Explain the role of glycogen in cellular metabolism

synthesized from excess glucose molecules by liver and muscle cells -serves as an intracellular glucose reserve

Describe the role of CCK release and its effects on proteins

CCK-stimulates the production and release of inactive pancreatic proenzymes. -As a result, they break down proteins into a mixture of dipeptides, tripeptides, and amino acids.

How is heat loss different between conduction and convection?

Conduction- direct transfer of heat through physical contact. Convection- heat loss to the cooler air in contact with the skin. The air warmed by the skin rises and it is repeatedly replaced by cooler air until there is no difference in temperature.

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

Counter current exchange

What is the difference between a micelle and a chylomicron?

Micelles- lipid-bile salt complexes formed in the intestinal lumen. Chylomicrons - lipoproteins formed in intestinal epithelial cells and contain newly synthesized triglycerides, cholesterol, and other lipids surrounded by phospholipids and proteins.

What two coenzymes transfer hydrogen atoms to the electron transport system?

NAD and FAD

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

The ammonium ions combine with carbon dioxide to form urea (in the urea cycle), which is ultimately excreted in the urine.

What does the liver do with 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 (LDLs) or very low density lipoproteins (VLDLs).

Define energetics

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

What molecule plays a key reactant role in both ATP production from fatty acids and lipogenesis

acetyl-CoA

Identify the fates of fatty acids

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

Most of the absorbed nutrients enter into which blood vessel?

branch of the hepatic portal vein and are transported to the liver

Define beta-oxidation

catabolism of fatty acids that produces molecules of acetyl-CoA

Why is digestion important?

cells throughout the body rely on the organic molecules from the food we eat for energy production and to replenish the intracellular nutrient pool

Define balanced diet

contains all the ingredients needed to maintain homeostasis and prevent malnutrition.

compare glycogenesis and glycogenolysis

glycogenesis- formation of glycogen from glucose glycogenolysis- breakdown of glycogen to glucose

Predict the effect of peripheral vasodilation on a person's body temperature

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

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

the citric acid cycle

Define insensible perspiration

the evaporation of water from the skin and alveolar surfaces of the lungs

Define oxidative phosphorylation

the generation of ATP as a result of the transfer of coenzymes to oxygen by electron carriers in mitochondria

Define thermoregulation?

the homeostatic control of body temperature

What is basal metabolic rate?

the minimum resting energy expenditure of an awake, alert person

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

the passageways for the diffusion of hydrogen ions from the inner membrane space to the matrix. -This movement of hydrogen ions powers the production of ATP by ATP synthase.

Explain the process of metabolic turnover

the process in which cells continuously break down and replace all their organic components except DNA

Briefly describe the citric acid cycle and explain its role

the reaction sequence that occurs in the matrix of mitochondria. I - role is to breakdown organic molecules, carbon dioxide molecules are released, and hydrogen atoms are transferred to coenzymes that deliver them to the electron transport system