U2.2 Cellular respiration Flashcards
Define respiration.
The breakdown of respiratory substrates to release energy.
What is glycolysis?
The breakdown of glucose to pyruvate in the cell cytoplasm.
Name the two phases of glycolysis.
The energy-investment phase and the energy pay-off phase.
What is required to phosphorylate glucose and intermediates during the energy-investment phase of glycolysis?
ATP (adenosine triphosphate)
What does phosphorylation in the energy-investment phase of glycolysis result in?
The generation of more ATP in the energy pay-off phase.
What is there a net gain of in glycolysis?
2ATP
What is the end product of glycolysis?
Pyruvate
What happens to pyruvate in aerobic conditions?
It is broken down to an acetyl group.
What does acetyl combine with, and what does it form?
Combines with coenzyme A to form acetyl coenzyme A.
Where does the citric acid cycle occur?
In the matrix of the mitochondria.
Where does glycolysis occur?
In the cytoplasm.
What does the acetyl group of acetyl coenzyme A combine with, and what does it form?
Combines with oxaloacetate to form citrate.
What is citrate converted back to, and how?
Oxaloacetate in a series of enzyme-controlled steps.
What does the citric acid cycle yield?
ATP and carbon dioxide.
What enzyme is involved in glycolysis and the citric acid cycle? What does it do?
Dehydrogenase enzymes.
Removes hydrogen ions and electrons from metabolites and pass them to the coenzyme NAD to form NADH.
What are passed through the electron transport chain?
Hydrogen ions and electrons.
Where is the electron transport chain located?
The inner mitochondrial membrane.
What is the electron transport chain?
A series of carrier proteins on the inner mitochondrial membrane.
Why are electrons passed along the ETC?
To release energy.
What does energy released from the ETC allow?
Hydrogen ions to be pumped across the inner mitochondrial memebrane.
What does the flow of hydrogen ions through the membrane protein ATP synthase produce?
ATP
What combines to form water in the ETC?
Hydrogen ions and electrons combine with oxygen.
Where and when does fermentation occur?
In the cell cytoplasm in the absence of oxygen.
Compare fermentation and aerobic respiration in terms of ATP production?
Much less ATP production in fermentation than aerobic respiration.
