Chapter 7 - metabolism

Question 1

metabolism

Answer 1

the sum of all chemical and physical processes by which the body breaks down and builds up molecules

Question 2

calorimeter

Answer 2

measures a food’s caloric content

Question 3

anabolism

Answer 3

the process of making larger, chemically complex molecules from smaller ones; critical for growth, repair, and the synthesis of chemical products essential for human functioning

Question 4

catabolism

Answer 4

the breakdown of larger, complex molecules to smaller, more basic ones; begins with digestion and includes old cells and tissues that are broken down for repair or replacement

Question 5

metabolic pathways

Answer 5

clusters of chemical reactions that occur sequentially to achieve a particular goal, occur in a specific part of a cell, and may be limited to specific organs or tissues

Question 6

dehydration synthesis

Answer 6

an anabolic process in which water is released as a byproduct

Question 7

hydrolysis

Answer 7

a usually catabolic process where a large molecule is broken down with the addition of water

Question 8

phosphorylation

Answer 8

the addition of a phosphate group to a compound

Question 9

oxidation

Answer 9

one half of an exchange reaction where a molecule donates an electron to an oxygen atom

Question 10

reduction

Answer 10

one half of an exchange reaction where oxygen gains an electron and becomes more negatively charged

Question 11

enzymes

Answer 11

substances that mediate chemical reactions

Question 12

coenzymes

Answer 12

non-protein substances that enhance or are necessary for enzyme activity, such as FAD, FADH2, and vitamins

Question 13

cofactors

Answer 13

typically minerals required for enzyme activity, such as iron, magnesium, zinc

Question 14

glycolysis

Answer 14

an anaerobic reaction occurring in the cytosol

Question 15

lipolysis

Answer 15

dietary and adipose triglycerides are broken down by lipase to yield glycerol and three free fatty acids

Question 16

ketones

Answer 16

byproducts of fat catabolism

Question 17

ketosis

Answer 17

occurs when ketones inappropriately lower blood pH

Question 18

ketoacidosis

Answer 18

occurs when blood pH falls, further resulting in severe dehydration

Question 19

proteolysis

Answer 19

dietary proteins are digested into amino acids or small peptides

Question 20

starvation

Answer 20

the body turns to its own tissues for energy

Question 21

alcohol oxidation

Answer 21

occurs primarily in the liver at a constant rate of about one drink per hour; gluconeogenesis by alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH), and microsomal ethanol oxidizing system (MEOS)

Question 22

first-pass metabolism

Answer 22

small amount of alcohol is oxidized in the stomach, before being absorbed into the bloodstream

Question 23

gluconeogenesis

Answer 23

making new glucose from nonglucose substrates, primarily glucogenic amino acids; maintains blood glucose during sleep, fasting, trauma, and exercise

Question 24

protein catabolism

Answer 24

can start to draw on vital tissue proteins such as skeletal and heart muscles and organ proteins for glucose production

Question 25

lipogenesis (de novo synthesis)

Answer 25

making fats from nonfat substances such as carbohydrates, amino acids, and alcohol; mostly occurs in liver cells as acetyl CoA units form fatty acid chains which combine with glycerol to form triglycerides when excess calories are consumed

Question 26

insulin

Answer 26

the primary anabolic hormone; increases in the blood after a meal, activates storage enzymes, and signals cellular uptake of glucose, fatty acids, and amino acids

Question 27

catabolic hormones

Answer 27

glucagon, epinephrine, and cortisol; trigger the breakdown of stored triglycerides, glycogen, and body protein for energy

Question 28

anabolic state

Answer 28

bloodstream is enriched with glucose, fatty acids, and amino acids