Chapter 24 Nutrition

Question 1

Define Nutrient

Answer 1

Provides nourishment. a nutrient is anything that nourishes a living being. We get our nutrients from what we eat.

Question 2

Define essential nutrient

Answer 2

a nutrient that the body cannot synthesize on its own and must be provided by the diet. The six essential nutrients include carbs, protein, fat, vitamins, minerals and water.

Question 3

Define Calorie

Answer 3

either of two units of heat energy.

Question 4

List the five major nutrient categories

Answer 4

Carbs, fats, vitamins, minerals and water

Question 5

great source of carbs

Answer 5

plant-based foods and whole grains

Question 6

great source of proteins

Answer 6

animal products and legumes

Question 7

great source of fats

Answer 7

fish oil and vegetable fats

Question 8

great source of vitamins

Answer 8

fruits and vegetables

Question 9

define metabolisim

Answer 9

all chemical reactions involved in maintaining the living state of the cells and the organism. Metabolism can be divided in catabolism and anabolism

Question 10

catabolism

Answer 10

breakdown of molecules to obtain energy.

Question 11

anabolism

Answer 11

the set of metabolic pathways that construct molecules from smaller units. These reactions require energy.

Question 12

Indicate the role of coenzymes used in cellular oxidation reactions.

Answer 12

REDOX enzymes require the help of a specific coenzyme, typically derived from one of the B vitamins. Although the enzymes catalyze the removal of hydrogen atoms to oxidize a substance, they cannot accept the hydrogen. Their coenzymes, however can act as hydrogen (or electron) acceptors, becoming reduced each time a substrate is oxidized.

Question 13

Substrate-level phosphorylation

Answer 13

occurs when high-energy phosphate groups are transferred directly from phosphorylated substrates to ADP

Question 14

Oxidative phosphorylation

Answer 14

Much more complicated, but is also releases most of the energy that is eventually captured in ATP bonds during cellular respiration.

Question 15

Glycolysis

Answer 15

anaerobic process occurs in the cytosol of cells. This pathway is a series of ten chemical steps by which gluclose is converted to two pyruic acid molecules.
Phase 1 Sugar activation gluclose is activated by phosphorylation and converted to fructose-1, 6-bisphospate
Phase 2 sugar cleavage frutose-1, 6-bisphosphate is cleaved into two 3-carbon fragments
Phase 3 sugar oxidation and formation of ATP the 3-cabon fragments are oxidized (by removal of hydrogen) and 4 ATP molecules are formed

Question 16

The Krebs cycle

Answer 16

in aerobic pathways, pyruvic acid is tranported into the mitochondrion.

Question 17

Differentiate between LDLs and HDLs relative to their structures and major roles in the body.

Answer 17

LDLs transport cholesterol to peripheral tissues and HDLs transport excess cholesterol from peripheral tissues to the liver and provide cholesterol to steroid-producing organs.
High levels of HDL are considered beneficial, as the cholesterol they contain is bound for removal, but high levels of LDL are considered a risk, because the cholesterol they contain may be laid down on vessel walls, forming plaques.