Cellular Respiration Flashcards
What is the role of ATP?
The universal link between catabolic and anabolic reactions.
Made up of adenosine + 3 phosphate groups.
What are the 3 stages of respiration?
Glycolysis
Citric acid cycle
Electron transfer chain
What are the 2 stages in glycolysis?
Energy investment stage
Energy payoff stage
What happens during glycolysis?
The breakdown of glucose into pyruvate in the cytoplasm.
ATP is required for the phosphorylation of glucose and intermediates during the energy investment stage.
This requires 2 ATP, eventually producing pyruvate which generates more ATP.
This leads to the generation of more ATP during the energy payoff stage.
What are the requirements and products of glycolysis?
Requirements-
Glucose and 2 ATP
Products-
Pyruvate, 4 ATP and 2NADH
What happens during the citric acid cycle?
Occurs in the matrix of the mitochondria.
In aerobic conditions, pyruvate is broken down to an acetyl group that combines with coenzyme A forming acetyl coenzyme A.
In the citric acid cycle the acetyl group from acetyl coenzyme A combines with oxaloacetate to form citrate.
During a series of enzyme controlled steps, citrate is gradually converted back into oxaloacetate.
This results in the generation of ATP and release of carbon dioxide.
What are the requirements and products of the citric acid cycle?
Requirements-
NAD, oxygen and pyruvate
Products-
Carbon dioxide, ATP and NADH
What happens in the electron transfer chain?
NADH pass electrons and hydrogen ions to the electron transport chain on the inner mitochondrial membrane.
Electrons are passed along the electron transport chain, releasing energy.
This energy is used to pump hydrogen ions across the inner mitochondrial membrane by active transport.
H ions increase in concentration and flow back across ATP synthase by diffusion.
This causes the ATP synthase to generate ATP from ADP+Pi.
Oxygen acts as the final hydrogen and electron acceptor to form water.
What are the requirements and products of the electron transport chain?
Requirements-
Oxygen and NADH
Products-
Water and ATP
What is fermentation?
Lack of oxygen means that only glycolysis can occur so fermentation occurs in the cytoplasm.
Fermentation produces less ATP than aerobic respiration.
What happens when fermentation occurs in animal cells?
Pyruvate is converted to lactate in a reversible reaction.
What happens when fermentation occurs in plant and yeast cells?
Ethanol and CO2 are produced in an irreversible reaction.
