1st Midterm Study Flashcards
what are the 3 main enzymes that comprise the anaerobic alactic system
mATPase
Creatine Kinase
Myokinase
Where is pyruvate dehydrogenase found in the muscle cell?
Mitochondrial matrix
How do people respond to creatine supplementation
Some people respond well and others respond poorly to Cr supplementation
Why can you not burn fats without some carbohydrate (CHO) being present?
Because oxaloacetate (required for the initiation of the TCA cycle) can only be formed from pyruvate, which is derived from CHOs
what are 4 enzymes associated with the lactate system
-phosphofructokinase
lactate
-dehydrogenase
-phosphorylase
-hexokinase
activated fatty acids in the sarcoplasm are known as
fatty acyl CoA
What is the fate of the majority of lactate produced by the body during heavy exercise?
It is used as a fuel by other tissues or adjacent muscle fibers
enzymes that make activated fatty acids are known as
fatty acyl CoA synthase
activated fatty acids are shuttled into mitochondria via this shuttle system
carnitine
what is the crossover concept as it relates to exercise metabolism
At low exercise intensities fat is the dominant fuel source for working muscle. As exercise intensity increases, fats become less important and CHOs become more important.
What amount of ATP is obtainable from glucose in (i) glycolysis only and (ii) complete oxidation via the TCA cycle and ETC?
2 and 30
glycogen would produce 3 and 31
The name given to the process whereby fats are utilized for fuel is
beta oxidation
what are the 4 main CHO and fat fuel depots in the body
-triglyceride stores in adipose tissue
-intramuscular triglyceride
-intramuscular glycogen
-liver glycogen
What is the major challenge when transporting fatty acids in the blood stream? How does the body deal with this?
Fatty acids are insoluble in plasma. They are transported in combination with a protein in the blood called albumin.
Name the two major hydrogen (electron) “taxicabs” within the cell. Where do they ultimately “deposit” their electrons?
Nicotinamide adenine dinucleotide (NAD) & flavine adenine dinucleotide (FAD).
NADH + H+ deposits its electrons into complex I and FADH2 into complex II
(this is why the ATP yield from FADH2 is slightly less than NADH + H+).
RER can climb above 1.0 in some cases because:
of non metabolic excess CO2 that is generated through bicarbonate buffering in blood plasma
Gas volumes measured during open circuit spirometry must be corrected for:
Water vapour content (humidity)
Temperature
Barometric pressure
Can you name the conditions associated with a gas volume expressed as “STPD”. In other words, what constitutes STPD? Why is expressing VO2 & VCO2 in relation to standard conditions necessary?
Standard temp = zero degrees celsius
Standard pressure = 760 mmHg (sea level pressure)
Dry = 0% humidity.
VO2 & VCO2 will vary according to different environmental conditions. To enable comparison between studies, standard conditions must be used.
Which of the following substances have been associated with fatigue?
Hydrogen ion accumulation
Calcium ion accumulation
Inorganic phosphate accumulation
The gross mechanical efficiency (GME) of upper body exercise is _________________ the GME for lower body dominant exercise
lower than
Fatigue occurs exclusively within the peripheral nervous system and skeletal muscle. (T/F)
False
Carbohydrates MUST be ingested in order for them to have an ergogenic effect during exercise. (T/F)
False! Swilling a carbohydrate solution in the mouth and spitting it out can have an ergogenic effect!
what is the rate limiting enzyme of the PCr system
Creatine Kinase
Which of the following is NOT an enzyme in the Krebs Cycle?
Alpha ketoglutarate dehydrogenase
Isocitrate dehydrogenase
3-HAD
Citrate synthase
3-HAD
3 hydroxyl CoA dehydrogenase
What are four enzymes associated with the Lactic system
Hexokinase
Phosphofructokinase
Lactate dehydrogenase
phosphorylase
what is the rate limiting enzyme in glycolysis
PFK
which enzyme converts pyruvate into acetyl CoA in the presence of oxygen
pyruvate dehydrogenase
what are the products of anaerobic glycolysis
2 ATP
2 NADH + H+
2 Pyruvate
what are three enzymes associated with the krebs cycle
citrate synthase
isocitrate dehydrogenase
alpha-ketoglutarate dehydrogenase
what does the enzyme citrate synthase do
combines acetyl CoA and oxaloacetate into citrate at the beginning stage of the krebs cycle
what is the rate limiting enzyme for the krebs cycle
isocitrate dehydrogenase
(isocitrate –> alpha-ketoglutarate
what is the rate limiting enzyme in the electron transport chain
cytochrome oxidase
(catalyzes the reduction of O2 and uses subsequent free energy to create a proton gradient across the membrane
what are the two activating steps in glycolysis
HK and PFK both use 1 ATP
what happens to lactate if its not changed back to pyruvate
10-25% for gluconeogenesis in liver (cori cycle)
5-10% provide carbon for transamination
what does the cori cycle do
in the liver, turns lactate into pyruvate into glucose in a process can gluconeogenesis
how does the lactic system react to training
increase of enzymes HK PFK phosphorylase, lactase dehydrogenase
increase in muscle buffering capacity
increase in glycogen stores
what are three metabolites that accrue after exercise
H+
Ca2+
Piow
quickly can the PCr system recover
half time 20-30 seconds
recovery in 2-8 minutes
requires ATP from aerobic system
how long to remove lactate from muscle during recovery
half time 12-20 mins
recovery in 60 mins
how long to remove lactate from blood during recovery
half time 15-25 mins
recovery in 60 mins
how long to remove H+ from blood during recovery
10-20 mins
recovery in 30-60 mins
how long to remove H+ from muscle during recovery
half time 5-8 mins
recovery in 12-20 mins
what are the byproducts of acetyl CoA formation
pyruvate dehydrogenase combines acetic acid and coenzyme A.
creates 2 NADH + H+, 2 CO2, 2 acetyl CoA
how many FADH and NADH does the krebs cycle produce
6 NADH + H+, 2 FADH2
2 ATP
4 CO2
what are the products of b-oxidation
1 FADH, 1 NADH, 1 acetyl CoA
a 16 carbon fatty acid will produce 106 ATP
