KA7 - Cellular Respiration Flashcards
What is respiration?
Respiration is the process by which energy is released from food. It occurs in all living cells
What is the main substrate writhing the respiration pathway?
Glucose
What three parts can the metabolic pathway involved in respiration be split into?
Glycolysis
Citric acid cycle
The electron transport chain
What is phosphorylation?
Phosphorylation is an enzyme controlled process by which a phosphate group is added to a molecule
Give an example of phosphorylation?
When low energy ADP and Pi combine to form high energy ATP
Where does glycolysis take place?
Cytoplasm
Does glycolysis require energy?
No
What is glycolysis?
Glycolysis involves the breakdown of glucose into two pyruvate molecules
What are the two phases involved in glycolysis?
An energy investment phase
An energy payoff phase
What happens to pyruvate in aerobic conditions?
In aerobic conditions, pyruvate is broken down into an acetyl group.
What does the acetyl group do?
The acetyl group then combines with coenzyme A to form acetyl coenzyme A
What is the stage after glycolysis?
The citric acid cycle
When does the citric acid cycle take place?
Only if oxygen is present
Where does the citric acid cycle take place?
The matrix of the mitochondria
What is the citric acid cycle controlled by?
Enzymes including dehydrogenase
What is the first stage of the citric acid cycle?
In the citric acid cycle, the acetyl group from acetyl coenzyme A combines with oxaloacetate to form citrate
What is the second stage of the citric acid cycle?
During a series of enzyme controlled steps, citrate is gradually converted back into oxaloacetate which results in the generation of ATP and release of carbon dioxide
What is the third stage of the citric acid cycle?
Dehydrogenase enzymes also remove hydrogen ions and electrons and pass them to the coenzyme NAD, forming NADH
What is the final stage of the citric acid cycle?
The hydrogen ions and electrons from NADH are passed to the electron transport chain
What is the last stage of respiration?
The electron transport chain
Does the electron transport chain require oxygen?
Yes
Where does the electron transport chain take place?
The inner mitochondrial membrane
Where is the majority of ATP made?
The electron transport chain(stage 3)
How is the majority of ATP made during the electron transport chain?
This is done using the energy from the electrons which have been removed during glycolysis and the citric acid cycle
What is the first stage of the electron transport chain?
Electrons are passed along the electron transport chain releasing energy
What is the second stage of the electron transport chain?
This energy allows hydrogen ions to be pumped across the inner mitochondrial membrane
What is the third stage of the electron transport chain?
These hydrogen ions then flow back through the membrane protein ATP synthase (an enzyme) which results in the production of ATP
What is the final stage of the electron transport chain?
Finally, the hydrogen ions and electrons combine with oxygen to form water
Oxygen is the final hydrogen acceptor of the electron transport chain
What is the role of ATP in the transfer of energy?
ATP is used to transfer energy to cellular processes which require energy
Give 4 example of cellular processes which require energy?
Muscle cell contraction
Transmission of nerve impulses
Cell division
Protein synthesis
