Ex. Nutrition Ch. 4 - Nutrient Role In Bioenergetics

Front 1

What is bioenergetics?

Back 1

The flow of energy within a living system

Front 2

What does the term aerobic mean?

Back 2

aerobic = oxygen requiring energetic reactions

Front 3

What is the law of thermodynamics?

Back 3

Energy is neither created nor destroyed, just transformed form one state to another without being used up

Front 4

What are the 3 forms of work in humans?

Back 4

Mechanical Work
Chemical Work (synthesizing cellular molecules)
Transport Work (cellular level)

Front 5

1. What is a reducing agent?
2. What is an oxidizing agent?

Back 5

1. a substance that donates or loses electrons as it oxidizes
2. a substance that gains electrons/is reduced

Front 6

What is lactic acid?

Back 6

compound formed when pyruvate accepts additional hydrogens caused by exercise

Front 7

What 2 forms does energy exist in?

Back 7

Potential and kinetic

Front 8

what is a redox reaction?

Back 8

a reaction that powers the body's energy transfer process

Front 9

What 2 factors do energy transformations in the body rely on?

Back 9

Oxidation-reduction reactions
chemical reactions that conserve and liberate the energy in ATP

Front 10

What are the cells' 2 major energy-transforming activities?

Back 10

1. extracting energy from food and conserving it within the bonds of ATP
2. Extracting and transfering the chemical energy in ATP to power biologic work.

Front 11

What part of ATP splits to liberate energy?

Back 11

The outermost phosphate bond

Front 12

What forms of biologic work does ATP power?

Back 12

ATP powers ALL forms of biologic work

Front 13

When is the energy available from a splitting ATP molecule?
How much oxygen is used?

Back 13

Energy from ATP breakdown is available immediately and without oxygen.

Front 14

What does the rate of energy transfer depend on?

Back 14

the intensity of the exercise

Front 15

What two substances represent the major energy sources that maintain continual ATP resynthesis?

Back 15

Glycogen and Fatty Acids

Front 16

What is phosphocreatine and what does it do?

Back 16

Phosphocreatine (PCr) is another high energy phophate compound that releases energy when creatine and phosphorus split.

Front 17

How long does PCr hydrolize for energy during an intense bout of exercise?

Back 17

About 10 seconds

Front 18

What is phosphorylation?

Back 18

energy transfer through phosphate bonds

Front 19

1. Where does most of the energy required for phosphorylation of ATP come from?

Back 19

oxidation of macronutrients

Front 20

What is a substance doing when it is oxidizing?

Back 20

it is donating electrons

Front 21

What is a substance doing if it is reducing?

Back 21

It is gaining electrons

Front 22

The oxidation-reduction process most often involves the transfer of ______ atoms.

Back 22

Hydrogen

Front 23

1. What process passes electrons extracted from hydrogen to oxygen?
2. What is the end result?

Back 23

1. The Respiratory chain
2. Water

Front 24

1. What is the final electron acceptor in the respiratory chain?
2. What does it combine with to form water?

Back 24

1. Oxygen is the final acceptor
2. O2 combines with H to form water

Front 25

How much of the potential energy in food nutrients transfers to ATP? (%)

Back 25

34%

Front 26

Where does cellular oxidation occur?

Back 26

on the inner lining of the mitochondrial membranes

Front 27

The energy released in macronutrient breakdown serves one purpose. What is it?

Back 27

To phosphorylate ADP to reform the energy rich compound ATO.

Front 28

What are the 4 sources of macronutrient fuel that supply substrate for for oxidation and formation of ATP?

Back 28

1. glucose derived from liver glycogen
2. triaglycerol and glycogen molecules stored in muscle cells
3. free fatty acids from triacylglycerol in the bloodstream
4. intramuscular and liver-derived carbon skeletons of amino acids

Front 29

What is the primary function of CHO?

Back 29

To supply energy for cellular work

Front 30

Describe the 2 stages of glucose degredation

Back 30

1. Stage 1 - glucose breaks down to 2 molecules of pyruvate. Energy transfers without oxygen (anaerobic)
2. Stage 2 - Pyruvate breaks down to CO2 and water. Energy transfers from these reactions require electron transport and accompanying phosphorylation (aerobic)

Front 31

1. What is the only macronutrient whose stored energy generates ATP anaerobically?
2. Why is this important in maximal exercise?

Back 31

1. CHO
2. When aerobic metabolic reactions can't supply enough energy to meet demand, ATP resynthesis must come from stored intramuscular glycogen.

Front 32

How much of the body's energy is supplied by carbohydrates during light and moderate aerobic exercise?

Back 32

about 1/3

Front 33

What does the brain metabolize for fuel under normal conditions?
What does the brain metabolize once this substance has run out?

Back 33

1, CHO under normal conditions (blood glucose)
2. fat as an alternative fuel after 8 days

Front 34

1. What is glycogenesis?
2. What compound regulates glycogenesis?

Back 34

1. The breakdown of glycogen into glucose
2. glycogen phosphorylase

Front 35

What is a good function of lactate?

Back 35

It provides H+ atoms for ATP production during intense exercise.

Front 36

What does the Cori cycle do? (3 steps)

Back 36

1. lactic acid is removed from the muscle and converted to lactate.
2. Lactate the eneters the liver for conversion to pyruvate and glucose synthesis.
3. glucose goes back to the muscle.

Front 37

How does lactic acid form? (2)

Back 37

1. Excess hyrdogens from the coenzyme NADH combine temporarily w/pyruvate to form lactic acid.

Front 38

What is the second stage of CHO breakdown called?

Back 38

The citric acid cycle (Krebs cycle)

Front 39

1. CHO depletes to 50% capacity after _____ (time) of initial exercise activity?
2. After this what starts to provide energy?

Back 39

1. 2 hours
2. fat energy after 2 hours

Front 40

What is the most important function of the Citric Acid Cycle?

Back 40

It generates H+ electrons for passage in the chain to NAD+ and FAD

Front 41

What is the body's most plentiful source of stored energy?

Back 41

Fat

Front 42

How many Kcal of energy is stored in fat reserves in the typical young male?

Back 42

60,000 to 100,000 Kcal

Front 43

What does lipase do?

Back 43

Lipase catalyzes triacylglyerol breakdown

Front 44

What (4) substances augment lipolysis from adipose tissue?

Back 44

Hormones: Epinephrin, norepinephrine, glucagon, and growth hormone.

Front 45

What macronurient powers exercise at 25% aerobic capacity?

Back 45

Fat oxidation

Front 46

What is lipogenesis and where does it occur?

Back 46

Lipogenesis is the formation of fat mostly in the cytoplasm of liver cells.

Front 47

What is transamination?

Back 47

The passage of nitrogen from an amine group to other compounds.
carbon skeletons of amino acids participate directly in energy metabolism.

Front 48

When glucose breaks down, how much energy is conserved in ATP bonds and what happens to the rest?

Back 48

34% of kcal is conserved in ATP bonds
Remainder dissipated as heat

Front 49

How many ATP molecules does the complete breakdown of a glucose molecule yeild?

Back 49

32

Front 50

What situation is happening if a biochemical steady state exists?

Back 50

Hydrogen atoms are being oxidized at their rate of formation

Front 51

The complete breakdown of a triacyglycerol molecule yeilds _____ ATP atoms?

Back 51

460