Respiration Flashcards
What are the two major categories of reactions?
- Catabolic
- Anabolic
What is a catabolic reaction?
It is the breakdown of a larger molecule into smaller molecules, usually accompanied with the release of energy
Give an example of a catabolic reaction
Respiration
What is an anabolic reaction?
The conversion of smaller molecules into larger molecules
Give an example of an anabolic reaction
Photosynthesis
Where does glycolysis occur?
In the cytoplasm
What is the major product of glycolysis?
2 x pyruvate molecules
Does glycolysis occur in anaerobic or aerobic conditions?
Both
What happens to the pyruvate molecules under anaerobic conditions in humans?
They are converted into lactic acid
What happens to the pyruvate molecules under anaerobic conditions in bacteria?
They are converted into ethanol and carbon dioxide (fermentation)
What is the net yield of the glycolysis cycle?
Net yield of 2 ATP
4 ATP produced and 2 ATP required in the process
What happens to pyruvate in aerobic conditions?
It is converted to acetyl coA and passed to the Kreb’s cycle
Where does the Kreb’s cycle take place?
In the matrix of the mitochondrion
What are the major products of the Kreb’s cycle?
3 NADH and 1 GTP (and carbon dioxide)
What is the importance of the Kreb’s cycle?
- It provides as a carbon source for amino acid synthesis
- It provides electrons for the electron transport chain (NADH)
- It generates energy (GTP)
What is the name for the formation of adenosine triphosphate from the electron transport chain?
Oxidative phosphorylation
When the electrons are passed sequentially from one electron carrier to another, which has a greater affinity for electrons?
The one that the electrons are being passed on to has a greater affinity for electrons. Oxygen has the greatest electron affinity of them all.
What is the final electron acceptor?
Oxygen
How many ATPs are formed from each NADH + H+?
3 ATP
How many ATPs are formed from each FADH2 in eucaryotes?
2 ATP
What are the major products of the electron transport chain?
- The regeneration of NADs for glycolysis
- The synthesis of ATPs for biosynthesis
How does the electron transport chain provide energy for hydrogen ions to be pumped across the membrane?
The electrons are decreasing in energy from one carrier to the next and releasing energy. This provides energy for the proteins in the membrane to pump hydrogen ions. H+ ions accumulate outside the membrane.
What is the proton-motive force?
It is the tendency of protons to return to the inside of the inner mitochondrial membrane.
What happens if oxygen is not present i.e. under anaerobic conditions?
Then there is no final acceptor.
Do the Kreb’s cycle and electron transport chain operate in anaerobic conditions?
No, there is no final acceptor for the electrons.
What is the net gain of ATP from the electron transport chain?
34 ATP
What is the net yield of ATP in the entire respiration cycle for 1 glucose molecule?
36 ATP
