Lecture 7: CSF Energy Flashcards
(37 cards)
What is ATP?
Adenosine triphosphate is a molecule that acts as the energy currency in our body
How does ATP act as an energy source?
The hydrolysis of ATP to ADP and an inorganic phosphate group releases energy
What is the ATP cycle?
The transfer of energy between complex and simple molecules in the body
What happens to glucose in the body as it is consumed?
Glucose in intestines -> absorbed into bloodstream -> entry into cell (facilitated by insulin) -> used for cellular respiration or storage
What is cellular respiration?
The controlled release of energy from organic compounds to produce ATP
What are the 4 main steps of cellular respiration?
Glycolysis
Pyruvate oxidation (link reaction)
Citric acid cycle (or Krebs cycle)
Electron transport chain
What is the overall formula for cellular respiration?
C6H12O6 + 6O2 -> 6CO2 + 6H2O + energy (in the form of ATP)
Where does glycolysis occur?
In the cytosol of the cell
Where does pyruvate oxidation occur?
In the matrix of mitochondria
Where does citric acid cycle occur?
In the matrix of mitochondria
Where does oxidative phosphorylation occur?
Across the inner membrane (involving intermembranal space and mitochondrial matrix)
What is the input and output of glycolysis?
Input:
1 Glucose
Output:
2 Net ATP (2 used and 4 produced)
2 NADH
2 Pyruvate molecules
Does glycolysis require oxygen?
No
What is NADH and FADH2?
Electron carriers that donate electrons for the electron transport chain
What is the input and output of pyruvate oxidation?
Input: 2 Pyruvate (per gluose)
Output:
2 Acetyl coA
2 NADH
2 CO2
Is oxygen required for pyruvate oxidation?
Yes
What is the input and output of citric acid cycle?
Input:
2 acetyl coA (per glucose)
Output: 2 ATP 6 NADH 2 FADH2 4 CO2
Does citric acid cycle require oxygen?
Yes, it is an aerobic process
What is substrate phosphorylation?
ATP generated by direct transfer (from a substrate) of phosphate group to ADP - occurs during glycolysis and citric acid cycle (low yield)
What is oxidative phosphorylation?
ATP generated from the oxidation of NADH and FADH2 and the transfer of electrons and pumping of protons. Much more efficient
Where is the electron transport chain?
Located on the inner membrane of mitochondria
What is the input and output of oxidative phosphorylation?
Input:
1 or 2 electrons depending on oxidation of NADH and FADH2 (from citric acid cycle)
Output:
26 to 28 ATP (per glucose molecule)
Does oxidative phosphorylation require oxygen?
Yes, oxygen is required to act as the final electron acceptor for the electrons of the ETC forming water
Explain how oxidative phosphorylation occurs
NADH and FADH2 are oxidised to donate 1 or 2 electrons
Electrons move along ETC from protein to protein
At each protein, electron gives up a small amount of its energy giving hydrogen pumps energy to actively transport H+ ions into the intermembranal matrix. As the H+ ions later diffuse down conc. gradient they pass through a ‘turbine’ known as ATP synthase which generates a large amount of ATP molecules.
Oxygen pulls the electron down the chain acting as the final electron acceptor where it is reduced to water.
