Energy Systems

Question 1

ATP

Answer 1

cells contain small quantities of atp

• due to the small amounts (body only stores 80-100 grams ATP)
• -changes in concentration of ATP occur rapidly with activity
• -atp must be resynthesized constantly
• there is a continuous supply of ATP through a variety of pathways

Question 2

3 energy systems

Answer 2

1. Creatine phosphate system
2. lactic acid system (glycolytic)
3. oxidative phosphorylation (aerobic)

Question 3

lactic acid system

Answer 3

lactic acid system=anaerobic metabolism

• energy supplied from glucose or stored glycogen within the muscle
• max exercise =60-180 seconds
• glycolysis

Question 4

creatine phosphate reaction

Answer 4

PCr+ADP–CPK–Cr+ATP

Question 5

CP system

Answer 5

immediate energy

• anaerobic
• main source of energy during extremely intense movements/exercise
• less than 10 seconds
• most likely depleted in 20-30 seconds
• muscles have more stored PCr than ATP
• ATP resynthesized from ADP and PCr at a quick rate

Question 6

glycolysis

Answer 6

• 10 step process by which glucose is broken down to create energy
• yields about 5% of total energy from one glucose molecule
• nets2-3 ATP

Question 7

rate limiting step in glycolysis

Answer 7

PFK (phosphofructokinase)

Question 8

inhibitor of glycolysis

Answer 8

high levels of O2

Question 9

lactate formation

Answer 9

• end product of glycolysis during intense exercise (80% aerobic capacity)
• serves as an energy source during the recovery from exercise (NAD+ scoops up hydrogen attached to lactate->process creates ATP when oxidized
• used as a source of energy by the Liver, Kidneys, and Heart

Question 10

lactate threshold

Answer 10

signifies the onset of appreciable lactate formation in muscle cell

• increase in the amount of lactate lowers the pH of blood during strenuous exercise (H+ ions)->metabolic acidosis-> cessation of exercise
• once O2 involved, H+ ions link with pyruvate

Question 11

aerobic system

Answer 11

primary means of energy production at rest

• oxidative phosphorylation
• provides nearly all energy transfer when exercise lasts more than a few minutes

Question 12

what occurs in early stages of aerobic respiration

Answer 12

O2 deficit

Question 13

steady rate reflects what

Answer 13

a balance between energy required by the working muscles and ATP production in aerobic metabolism

Question 14

oxidative phosphorylation

Answer 14

coupled with the electron transport chain, oxidative phosphorylation synthesizes atp by transfering electrons from NADH and FADH2 to oxygen (redox)

• more than 90% of ATP synthesis takes place in the respiratory chain from the coupling of these two processes
• net ATP produced from one glucose molecule=32 atp

Question 15

krebs cycle (citric acid cycle)

Answer 15

process of extracting energy from pyruvate

• pyruvate converts to acetyl coa which enters cycle
• acetyl coa joins with oxaloacetate forming citrate which proceeds through the cycle
• NADH takes up H+ ions that are spit out, takes them to electron transport chain

Question 16

electron transport chain

Answer 16

-majority of atp is generated by the large amount of hydrogens created during the citric acid cycle and oxidized via the aerobic process of the electron transport chain

Question 17

coupling of reactions

Answer 17

coupling of citric acid cycle and the electron transport chain nets a total of atp 30-38, usually 32.