week 5: The muscular system: Acute muscular responses to exercise: anaerobic performance

Question 1

anaerobic metabolism most needed in

Answer 1

first 30 seconds of maximal exercise

Question 2

energy systems that contribute

Answer 2

ATP-Pc system
glycolysis
aerobic metabolism

Question 3

major pathways of anaerobic ATP pathways

Answer 3

1. creatin kinase reactions
2. anaerobic glycolysis
3. adenylate kinase reaction

Question 4

creatine kinase reaction

Answer 4

Pcr + H+ +ADP -> ATP + Cr
Pcr immediate defense
combines with proton and ADP
allows reformation of highh energy phosphate in form of ATP

Question 5

anaerobic glycolysis

Answer 5

glycogen + 3ADP + Pi ->
3ATP + 2La- + 2H+
glycogen converted to lactate and proton

Question 6

adenylate kinase reaction

Answer 6

2ADP -> ATP + AMP
with AMP quickly degraded IMP & NH4+ via AMPD

Question 7

two key factors why anaerobic metabolism is important to skeletal muscles during exercise

Answer 7

1. slow response of oxidative metabolism (increase in mitochondria uptake of oxygen) to turn on (O2 deficit)
2. maximal rate of ATP provision is limited by oxidative metabolism

Question 8

ATP needed for

Answer 8

1. cross bridge cycling
   Myosi ATPase> contraction
2. Ca2+ ATPase> relaxation

Question 9

two major challenges during immediate exercise

Answer 9

1. depletion of PCr
2. lactate (and H+) accumulation

Question 10

depleting stores of PCr occurs when and the consequence of it

Answer 10

limits maximum capacity to maintain high power outputs

occurs as ex intensity increases as % of VO2 max

Question 11

when does glycolysis occur in cytosol (anaerobic)

Answer 11

pyruvate cant enter mitochondria

Question 12

if anaerobic glycolysis in cytosol occurs at more rapid rate than what NADH can be reoxidised and pyruvate can enter mitochondria

Answer 12

lactic acid produced
(lactate and H+)
associated with acidosis

Question 13

exercise induced acidosis

Answer 13

anaerobic exercise can challenge acid-base balance due to increased H+ production
detrimental for muscle performance

Question 14

sources of acidosis during exercise - aerobic

Answer 14

aerobic metabolism of glucose> carbonic acid > H+

Question 15

sources of acidosis during exercise - anaerobic

Answer 15

anaerobic metabolism (glycolysis) of glucose > lactate> H+

Question 16

another source of acidosis during exercise

Answer 16

ATP breakdown and release of H+

Question 17

anaerobic athletes and buffering capacity

Answer 17

many anaerobic athletes have high capacity to buffer increases in H+
anaerobic training allows an increase in muscle buffering capacity by up to 50%

Question 18

first line of defense buffers located

Answer 18

muscle

Question 19

second line of defense buffers located

Answer 19

blood

Question 20

cellular buffer systems

Answer 20

bicarbonates
phosphates
proteins
carnosine
transport of H+ out of muscle

Question 21

blood buffer systems

Answer 21

bicarbonate
phosphates
proteins

Question 22

respiratory compensation for metabolic acidosis

Answer 22

blow off excess CO2 from lungs

Question 23

key H+ transport mechanisms linking muscle-to-blood

Answer 23

sodium-hydrogen exchanger
(NHE)
monocarboxylate transporters (MCT)

Question 24

sodium hydrogen exchanger

Answer 24

Na+ moves into muscle from blood
H+ moves out of muscle into blood

Question 25

monocarboxylate transporter

Answer 25

lactate moves into blood from muscle
H+ moves into blood from muscle

Question 26

power output over repeated sprints with rest

Answer 26

power output decreases
(peak and mean)

Question 27

reasoning for decreasing power output over repeated sprints

Answer 27

relative contribution of anaerobic metabolism reduced with increasing sprint number
very significant (ie 65% between sprint 1-10) in anaerobic energy provision
ATP turnover rate decreased