U2:KA2 - Cellular respiration Flashcards
(22 cards)
What do ATP molecules have?
A high level of chemical energy
What is the chemical energy in ATP used for?
Cells use it to transfer energy for cellular processes requiring energy
When is energy released from ATP?
When a phosphate is removed
What is the energy release when glucose is broken down stored as?
ATP
What is glycolysis?
The breakdown of glucose into 2 pyruvate molecules
Where does glycolysis occur?
The cytoplasm
Is glycolysis anaerobic or aerobic?
Anaerobic
What are the two steps of glycolysis
Energy investment and energy payoff
What enzyme removes hydrogen ions from glucose?
Dehydrogenase enzyme
What is NAD?
A coenzyme which acts as a hydrogen acceptor and carrier
What is NADH?
It is NAD when it binds to a hydrogen
What is phosphorylation?
The addition of a phosphate group to a molecule
Is the citric acid cycle aerobic or anaerobic?
Aerobic
What happens during the citric acid cycle?
Pyruvate diffuses from the cytoplasm into the matrix of the mitochondria, pyruvate is broken down into an acetyl group, this becomes attached to a coenzyme forming acetyl coenzyme A (acetyl CoA), hydrogen ions and electrons are removed and become attached to the coenzyme NAD forming NADH, carbon dioxide is released, the acetyl group from acetyl CoA combines with oxaloacetate to form citrate, citrate is converted, through a series of enzyme controlled reactions, back into the oxaloactate, carbon dioxide is released and diffuses out of the cell as a waste product and is expired by breathing out, the hydrogen ions and electrons are removed from intermediates and by dehydrogenase enzymes bind to NAD which is reduced to form NADH, the high energy electrons are passed to the electron transfer chain, ATP is synthesised in the citric acid cycle
How many ATP does the energy investment stage of glycolysis require?
2 ATP
How many ATP molecules does the energy payoff phase of glycolysis create?
4 ATP
What are the 3 stages of respiration?
Glycolysis, citric acid cycle and the electron transport chain
What is the electron transport chain?
It’s a collection of proteins attached to the inner mitochondrial membrane
What happens during the electron transport chain?
NAHD release electrons to the electron transport chain where they pass along the chain, releasing energy, the energy is used to pump hydrogen ions across the inner mitochondrial membrane, the return flow of these hydrogen ions back across the inner mitochondrial membrane generates ATP, the enzyme atp synthase catalyses this reaction, ATP synthase requires a flow of hydrogen ions to drive this reaction, at the end of chain, electrons and hydrogen ions combine with oxygen to form water
What takes place in the absence of oxygen?
Fermentation
What happens during fermentation in animals?
A hydrogen from NADH is added to pyruvate forming lactate, the NAD formed is free to pick up more hydrogens from intermediates in glycolysis
What is the formula for aerobic respiration?
Glucose + oxygen-> carbon dioxide + water + energy
