2.2 Cellular Respiration Flashcards
What is respiration
Enzyme controlled reactions that generate ATP by the release of energy from food
Where is ATP made
The mitochondria
When is the energy released from ATP
When the terminal (last) phosphate is removed
Name the 3 stages of cellular respiration
Glycolysis, Citric acid cycle, Electron transport chain
Where does glycolysis occur
The cytoplasm
What is glucose broken down into during glycolysis
Pyruvate
Name Stage 1 in glycolysis
Energy investment stage
How many ATP are needed for energy investment
2
What is phosphorylation
ATP molecules gaining a phosphate
What is stage 2 called and how many ATP does it produce
Energy payoff and 4
What is the net gain of glycolysis
2
What do dehydrogenase enzymes do
Remove hydrogen ions and electrons from intermediates
What is NAD
Hydrogen carrier/acceptor
What is NAD’s role
Picks up hydrogen ions and electrons to form NADH and carries them to the electron transport chain
What type of reaction is glycolysis
Aerobic (with oxygen)
Where does the citric acid cycle occur
The central matrix
The citric acid cycle will only occur if what is present
Oxygen
What is the first stage of the CAC
Pyruvate is broken down into an acetyl group which binds with coenzyme A to from acetyl coenzyme A
What is the second stage of the CAC
The acetyl from acetyl coenzyme A combines with oxaloacetate to form citrate
How many ATP does the citric acid cycle produce
1
What is the by product of the CAC
Carbon dioxide
What is the electron transport chain
A chain of protein molecules attached to the inner membrane of the mitochondria
Where does the NADH in the ETC come from
Glycolysis and the citric acid cycle
What is stage 1 of the ECT
Electrons flow along the electron transport system and release energy
What is stage 2 of the ETC
The energy released is used to pump hydrogen ions across the mitochondrial membrane to the inner membrane space
What is stage 3 of the ETC
The returning flow of hydrogen goes back into the matrix through ATP synthase, generating ATP from ADP + Pi
What is the last stage of the ETC
Electrons and hydrogen combine with oxygen to form water
What is the final hydrogen ion and electron acceptor
Oxygen
What is ATP synthase’s role in the ETC
Adds phosphates to ADPs
What is the alternative the the citric acid cycle when oxygen is not present
Fermentation
Where does fermentation occur
In the cytoplasm
When does fermentation occur in animals
During strenuous exercise and is reversible
Describe fermentation in animals
Glucose pyruvate > O2 debt builds up > Lactate > O2 debt repaid > Glucose pyruvate
Describe fermentation in plants
Glucose > Pyruvate > Ethanol + CO2
Why is fermentation in plants irreversible
Cells are damaged because by the high concentration of alcohol and the loss of carbon dioxide from the cells
