Cellular respiration

Question 1

What is ATP used for?

Answer 1

to transfer energy from respiration to energy requiring reactions

Question 2

How is ATP synthesised?

Answer 2

from ADP and Pi through phosphorylation

Question 3

Why is there a constant supply of ATP in cells

Answer 3

because it is synthesised as fast as it is used

Question 4

What happens during cellular respiration

Answer 4

glucose is broken down

hydrogen ions and electrons are removed by dehydrogenase releasing energy from glucose to form ATP

Question 5

Why is glycolysis said to produce a net gain of 2ATP

Answer 5

4 ATP are being produced in energy pay off phase but 2 ATP are used up in every investment phase therefore only gain 2 ATP

Question 6

Describe glycolysis

Answer 6

glycolysis occurs in the cytoplasm
glycolysis is a series o fenzyme controlled steps
oxugen is not needed
glucose is broken down to pyruvate
during the energy investment phase 2 atp are produced per glucose molecule
during the energy pay off phase 4 atp are produced per glucose molecule
during glycolysis there is a net gain of 2 atp

Question 7

Where does the phosphate for the phosphorylation come from in glycolysis>

Answer 7

ATP

Question 8

Are the phosphorylation steps in glycolysis reversible or irreversible?

Answer 8

irreversible

Question 9

What is the function of the matrix of mitochondria

Answer 9

where citric acid cycle occurs

fluid filled centre

contains enzymes for citric acid cycle

Question 10

What is the function od the inner membrane folds on the mitochondria

Answer 10

contains electron transport chain

proteins such as ATP synthase are attached to inner membrane

Question 11

In muscle cells, liver and sperm cels there are a high concentration of mitochondrian in the cytoplasm why?

Answer 11

there are more active and requrie a lot of ATP therefore they need a high concentration of mitochondrian to do aerobic respiration to produce ATP

Question 12

Which enzymes are needed to remove hydrogen ions and electrons from pyruvate and citrate.

Answer 12

dehydrogenase enzymes

Question 13

What is the role of dehydrogenase enzymes in respiration?

Answer 13

remove hydrogen ions and electrons from molcules which are passed to the enzyme carrier NAD to form the reduced carrier NADH

Question 14

What are the steps of the citric acid cycle?

Answer 14

pyruvate progresses ot the citric acid cycle if oxygen is avilable
pyruvate is broken down to an acetyl group that combines with coenzyme a to be trasnffered ot the citric acid cycle as acetyl coenzyme a
the acetyl group from acetyl coenzyme a combines with oxaloacetate to form citrate followed by the enzyme controlled steps of the cycle
the cycle results in the generation of atp release of carbon dioxide and the regeneration of oxaloacetate

Question 15

Where does the citric acid cycle occur

Answer 15

Matrix of the mitochondria

Question 16

What is required for pyruvate to pass to the citric acid cycle

Answer 16

oxygen

Question 17

Where does the electron transport chain occur

Answer 17

inner membrane of mitochondria

Question 18

What are the stages of the electron transport chain?

Answer 18

the electrons transport chain is a series of carrier proteins attached to the inner mitochondrial membrane

NADH release the electrons to the electron transport chain where they pass along the carrier proteins releasing energy.

The energy is used to pump hydrogen ions across the inner mitochondrial membrane protein ATP synthase and produces the bulk of the ATP generated by cellular respiration

the final hydrogen/ electron acceptor is oxygen which combines with hydrogen ions and electrons to form water

Question 19

What occurs during the energy investment phase of glycolisis

Answer 19

phosphorylation of glucose and intermediates

Question 20

Name the enzyme required to produce ATP

Answer 20

ATP synthase