Lec 12 Anerobic Metabolism Flashcards
Describe the immediate system pathway
Muscles contraction starts
1) ATP broken down into H+, ADP, and Pi+
—> this increases calcium and by products such as ADP, Pi, and H
These byproducts then activate CK enzyme
2) CK accelerates breakdown of PCR
3) PCR gives one Pi to ADP to resynthesizes ATP
PCR + H + ADP —-> ATP + CR
What is used to synthesize PCR
ATP from oxidative metabolism
Anaerobic metabolism
Involves the ________ system
Involving what three processes
Glycolytic system
Glycogenolysis, glycolysis, lactate production
What is the only macronutrient that can generate ATP both aerobically and anaerobically
Carbohydrates
Where are carbohydrates available from during exercise (4)
Blood, muscle, liver, ingested
How does glucose enter the muscle cell
GLUTE4
GLUT4
Is a ____________ and not an __________
Are specific to __________
Transport protein and NOT an enzyme
Are specific to muscle cells
GLUT4
Follows ___________
And is ____________ sensitive
Follows facilitated diffused aka follows a concentration gradient
And is insulin sensitive - activated by insulin receptors?
ANAEROBIC
What happens when glucose first enters a muscle cells
Hexokinase (HK)
—Converts glucose to glucose 6 phosphate (G6P)
— ATP is hydrolyzed to ADP, Pi, and H
Pi attaches to glucose to produces G6P
Note at this point when G6P is produced it CANNOT leave the cell and is an irreversible reaction
ANAEROBIC
What are the two fates of G6P
1) undergo glycolysis
2) stored as glycogen
ANAEROBIC
What converts G6P to G1P
Phosphoglucomutase
ANAEROBIC
What converts G1P to glycogen
Glycogen synthase/ phosphorylase ( PHOS)
What happens during anaerobic glycolysis
PFK converts G6P to pyruvate
?????
Finish
What occurs during glycogenolysis
And where does it occur
Occurs in the sarcoplasm (outside of mitochondria)
Glycogen breakdown to G1P catalyzed by PHOS
Yields 3 ATP
Requires 1 and produces 4
Glycogen phosphorylase aka PHOS
It is a ____ ______ enzyme
What increases it activity and what decreases its activity
Rate limiting enzyme
Increased by calcium, AMP, Pi, epinephrine
Decreased by H, ATP, G6P
How many ATPs are produced from glucose and glycogen (anaerobic)
Glucose 2 ATP
Glycogen 3 ATP
What is McArdle disease
What does it cause
What do people experience
Mutation in the PYGM gene causing more productions of glycogen phosphorylase enzyme
Leads to an inability to break down glycogen effectively
People experiments muscle weakness, fatigue, and cramping especially during exercise
What are the two types of glycolysis
What are the differences? Oxygen, speed, ATP production, products?
Anaerobic and aerobic
Anaerobic
Does not need oxygen, fast, low ATP production, lactate
Aerobic
Requires oxygen, slow, high ATP production, pyruvate
When there is a build up of pyruvate outside the mitochondria what happens? What causes this to occur
Pyruvate turns into lactate
Occurs through lactate dehydrogenase LDH
this change requires NADH2 to convert to Nad +
Mismatch between glycolytic rate and capacity of the mitochondria to accept pyruvate
Happens when there is an accumulation of pyruvate and NADH2
Lactate is NOT _____ _____
Rather it is a ________ H+ by _______
Lactic acid
Is a buffer of H+ by absorption
What happens to lactate at rest
Will get converted by to pyruvate
Or will go to the brain, heart and liver that uses it as energy
Does lactate cause fatigue?
NO
LACTATE IS A FUEL
Converted back to pyruvate or converted to glycogen
What causes fatigue
When ATP demand is greater than aerobic metabolism ATP supply
When there is a mismatch, cellular ph drops
This impairs enzyme activity and cross bridge cycling
What happens during a 30 sec bout of high intensity exercise
What pathways are being used?
PCR high contributions at first and then VERY little by the end
Glycolysis high and the beginning and then decreases
Oxidative phosphorylation increases gradually over time
