Chapter 2: Quiz 2

Question 1

ATP-PCr/ Phosphagen System

Answer 1

high energy molecule in muscle used to reform ATP

SOURCES: food:red meat/meat. Fish (best source) Body manufactures creatine in live and kidney

• Anaerobic
• Cytoplasm
• Simplest (one reaction/ one enzyme)
• Quickest
• Provides energy at the onset of exercise and yo sustain high-intensity muscular activity for - 10 sec.

create phosphocreatine until you are in recovery

100 M dash or anything shorter

Question 2

Recreating ATP with PCr

Answer 2

PCr + ADP —-(CK)—- Cr + ATP

Question 3

ATP - PCr System

Answer 3

-limitation-muscle cells store only small amounts of PCr.

need ATP to form PCr

• can’t do until recovery
• 50-70% restored in 30 sec
• full recovery in 10-30 min

creatine supplementation

• quicker recovery
• most studies show more work when exercise is repeated
• muscle swell=water

Question 4

Control of ATP-PCr System Creatine Kinase (CK)

Answer 4

-PCr breakdown catalyzed by CK

CK controls rate of ATP production

• Negative feedback system
• When ATP levels decrease (ADP increase), CK activity increases
• When ATP levels increase, CK activity decrease

Question 5

Glycolytic System

Answer 5

• anaerobic
• cytoplasm
• ATP yield: 2 to 3 mol ATP/ 1 mol substrate
• duration: 15 s to 2 min

*400m Dash

Question 6

Anaerobic Glycolysis

Answer 6

When a decrease in O2, pyruvic acid —> Lactic Acid
*PURPOSE -to reform NAD+ to allow glycolysis to continue

LIMITATION: lactic acid dissociates to lactate–> decrease in pH===> FATIGUE

High Intensity Exercise=15 sec-2min

Question 7

Energy Yield from Anaerobic Glycolysis starting from Glucose

Answer 7

invest: -2 ATP
payoff: +4 ATP
net: 2 ATP

Question 8

Energy Yield from Anaerobic Glycolusis starting from G1P

Answer 8

invest: -1 ATP
payoff: +3 ATP
net: 3 ATP

Question 9

Lactate Threshold and Endurance Performance

Answer 9

• LT, when expressed as % VO2max, is one of best determinants of athletes pace in endurance events
• Untrained LT: ~50% to 60% of their VO2max
• Trained LT: ~70% to 80% VO2max

Question 10

Fates of Lactate

Answer 10

• Heart has LDH-h which takes lactate and makes pyruvate
• Oxidized to pyruvate to go Krebs. Can happen within the cell. Slow twitch muscle fibers can oxidize lactate to pyruvate better than fast twitch muscle fibers, so sometimes lactate is transported from fast twitch fibers to slow twitch fibers to be utilized
• Can enter Cori cycle where blood lactate goes to the liver to be changed to liver glycogen or glucose which may be sent back through glycolysis

Question 11

Energy Sources for Early Minutes of Intense Workout

Answer 11

• Combined actions of ATP-PCr and glycolytic systems allow muscles to generate force in the absence of O2
• These two energy systems are the major energy contributors during the early minutes of high-intensity exercise

Question 12

Glycolytic System (PFK)

Answer 12

• phosphofructokinase )PFK)
• rate liminting enzyme
• decrease ATP. increase ADP. increase PFK activity
• increase ATP, decrease PFK activity

-also regulated by products of Krebs Cycle

Question 13

Oxidative (Aerobic) Systems

Answer 13

• Mitochondria
• Large # ATP
• Limited by availibility
• Activity of long duration
• CHO, fat, and pro
• CO2

Question 14

4 Parts of CHO Oxidative Metabolism

Answer 14

1. Glycolysis
   - PA shuttled into mitochondrion
2. PA ==> Acetyl CoA (ACoA)
3. Krebs Cycle
4. Electron Transport Chain (ETC)

Question 15

PA to A CoA & Krebs Cycle

Answer 15

• Each time 1 PA is converted to 1 A CoA, 1 NADH + H+ is made
• A CoA turns Kreb’s Cucle
• 1 turn of Krebs=1 ATP, 1 FADH2, 3 NADH + H

Question 16

Electron Transport Chain

Answer 16

H+ released during many of the reactions in above steps combines w/1 or 2 coenzymes

• NAD+: nicotinamide adenine dinucleotide
• FAD+: flavin adenine dinucleotide

CHEMIOSMOTIC HYPOTHESIS

• cytochromes
• proton pumps
• ATP synthase
• terminal electron receptor

OXIDATIVE PHOSPHORYLATION: formation of ATP in ETC

SUBSTRATE LEVEL PHOSPHORYLATION: making ATP as direct product (glycolysis, Krebs Cycle)

Question 17

Oxidation of Fat

Answer 17

• triglycerides broken by lipolysis into 1 glycerol + 3FFAs
• glycerol oxidation yields 15 ATP

-Most energy from fat comes from the FFAs in B-oxidation

Question 18

B-oxidation

Answer 18

• Even # of C’s
• FFA enzymatic activation, consumes 2 ATP
• FFAs cut into 2-C units of Acetic Acid–> A CoA=> Krebs & ETC

-Each round of B-oxidation produces 1 NADH + H and 1 FADH

Question 19

Full oxidation of a triglyceride containing 3 16-C FFAs

Answer 19

• glycerol oxidation yields 15 ATP
• Each 16-C FFA yields 106 ATP
• Thus, 15+3 (106) = 333ATP

Question 20

CHO vs, Fat

Answer 20

• Fat provides more kcals per molecule consumed, but fat uses more O2 to burn
• Fat 9.4 kcal/g 23 O2/palmitic acid
• CHO 4.1 kcal/g 6 O2/glucose

-O2 delvery to cells limited by CV and respiratory systems, so CHO preferred fuel as exercise intensity increases. Fat used for lower intensity work

• Both CHO and fat oxidation are inefficient
• 1/3 of energy used for work
• 2/3 lost as heat