Cellular Respiration Flashcards
What is cellular respiration?
A series of metabolic pathways that release energy from food.
What does cellular respiration regenerate?
ATP - Adenosine Triphosphate.
What is ATP composed of?
One adenosine and three inorganic phosphates (Pi).
Adenosine - Pi - Pi - Pi
How is the energy released from ATP?
When the final bond breaks.
What happens when ATP’s bonds are broken?
Left with ADP - Adenosine Diphosphate.
Adenosine - Pi - Pi + Pi
What is glycolysis?
The breakdown of glucose to pyruvate in the cytoplasm.
Where does glycolysis take place?
In the cytoplasm
What is ATP required for during the energy investment stage of glycolysis?
For the phosphorylation of glucose and intermediates.
When does fermentation take place?
In the absence of oxygen.
What happens during fermentation in animal cells?
Pyruvate is converted to lactate in a reversible reaction.
What happens during fermentation in plants and yeast?
Ethanol and CO2 are produced in an irreversible reaction.
Compare ATP between fermentation and aerobic respiration.
Fermentation results in much less ATP being produced than aerobic respiration.
What is phosphorylation?
An enzyme-controlled process where a phosphate group is added to a molecule.
What are the three stages of cellular respiration?
- glycolysis
- citric acid cycle
- electron transport chain
Where does glycolysis take place?
Cytoplasm
Where does the citric acid cycle take place?
Matrix of the mitochondria
Where does the electron transport chain take place?
Inner mitochondrial membrane
What is glycolysis?
The breakdown of glucose into pyruvate.
Glucose > intermediate products > Pyruvate.
Is oxygen required for glycolysis?
No
What is required for converting glucose to intermediate products and what is this stage called?
2 ATP are required in the energy investment stage.
What happens when the intermediate products are formed into pyruvate?
There is a net gain of 2 ATP - called the energy pay-off stage.
What removed hydrogen ions and electrons from the pyruvate molecules?
Dehydrogenase enzymes
Where do hydrogen ions and electrons get passed?
To the coenzyme NAD to form NADH.
Does the citric acid cycle require oxygen?
Yes
What is a series of dehydrogenase enzyme-controlled reactions resulting in the generation of ATP and release of CO2 and H2?
The citric acid cycle.
What is the first step of the citric acid cycle?
Pyruvate is converted to acetyl. Acetyl combines with coenzyme A to form acetyl coenzyme A.
What is the second step of the citric acid cycle?
Acetyl coenzyme A combines with oxaloacetate to form citrate which reacts with CO2 to form oxaloacetate and then all over again.
Where are the hydrogen ions and electrons passed on from the citric acid cycle?
To the electron transport chain.
Does the electron transport chain require oxygen?
Yes
What happens in the electron transport chain?
Oxygen, hydrogen ions and electrons form NADH to generate ATP and form water.
What is the electron transport chain?
A series of carrier proteins attached to the inner mitochondrial membrane.
How is the ATP generated in the electron transport chain?
Hydrogen ions flow through the ATP synthase protein back through the inner membrane generating 36 ATP.
