energy system Flashcards
1
Q
What is energy and how does it manifest in the human body?
A
- The property of matter and radiation which manifests as a capacity to perform work
- It manifests in the human body through movement, cell function and maintenance of life
2
Q
What is the function of myofibrilar ATPase?
A
- It’s the enzyme that catalyzes the ATP hydrolysis reaction (ATP+H2O = ADP + H+ + Pi + 31kJ energy (30% efficient)
- Located in the head of the myosin molecule
- Energy from ATP is needed when the myosin head is drawing / pulling
3
Q
Explain the energy yield of the lactic acid system?
A
- Glycolysis converts glucose into pyruvate. This reaction requires the input of 2 ATP.
- The total yield is 4 ATP, therefore balance is a gain of 2 ATP per glucose converted to pyruvate
4
Q
What determines the fate of pyruvate – describe the pathways?
A
- The presence of oxygen determines the fate of pyruvate metabolism
- With no presence of oxygen pyruvate enagages with the NADH molecules produced during glycolysis and it is converted to lactate by the enzyme lactate dehydrogenase. Lactate is good as it and engages and buffers hydrogen ions and reduces acidosis and fatigue and lactate can be converted back to pyruvate in the liver.
- If oxygen is present pyruvate is converted into AcetlycoA by the enzyme pyruvate dehydrogenase, which can enter into the kreb cycle.
5
Q
Explain the TCA cycle yield of energy and what happens to the reduce coenzymes?
A
- Pyruvate enters the TCA cycle as AcetylcoA. This cycle produces small amounts of energy but large amounts of reduced coenzymes (NADH) which enter the electron transport chain
- The electron transport chain takes electrons and hydrogens and removes them from the cell/mitochondrial membrane and takes them into the intermembrane space.
- The gradient of hydrogen in the intra intermembrane space increases and through ATP synthase enzyme complex for every 3 hydrogens ions passed through 1 ATP is produced.
