Cellular respiration (1.7)

Question 1

What is glycolysis (1)

Answer 1

Is a breakdown of glucose and pyruvate on the cytoplasm.

Question 2

What is a molecule of ATP made up of (1)

Answer 2

Adenosine + 3 Inorganic phosphate (Pi) molecules.

Question 3

What is phosphorylation (1)

Answer 3

Addition of phosphate to a substance.

Question 4

When is energy released from ATP (1)

Answer 4

Energy stored in ATP is released when the bond attaching the last phosphate (Pi) group is broken.

Question 5

Where does the energy come from to make ATP from ADP + Pi in respiration (1)

Answer 5

The breakdown of glucose in during respiration.

Question 6

Why is there a constant supply of ATP in our cells (1)

Answer 6

There is a constant supply of ATP in our cells as it is synthesised as fast as its used.

Question 7

What are the 3 stages of aerobic respiration (3)

Answer 7

Glycolysis; Citric Acid Cycle; Electron Transport Chain.

Question 8

What is glycolysis (1)

Answer 8

The breakdown of glucose into 2 pyruvate in the cytoplasm.

Question 9

What happens in glycolysis (first half) (3)

Answer 9

Described as the energy investment phase. 2 phosphorylation’s occur; In each of these, a molecule of ATP is converted into ADP; The phosphate group is added to the intermediate molecule.

Question 10

What happens in glycolysis (second half) (4)

Answer 10

Described as the energy pay off phase; 4ATPs are generated; giving a net gain of 2 molecules of ATP; Dehydrogenase removed hydrogen ions are passed on to the co-enzyme NAD to form NADH (nad comes in to gab hydrogen (nadh) then leaves) ; NADH is then taken to the electron transport chain.

Question 11

What is the purpose of dehydrogenase (1)

Answer 11

To remove hydrogen ions and electrons and pass them to the co-enzyme NAD, forming NADH.

Question 12

In aerobic conditions what is pyruvate broken down into (1)

Answer 12

An acetyl group.

Question 13

What is released from the break down of pyruvate into an acetyl group (1)

Answer 13

CO2 is released and dehydrogenase removes hydrogen ions and passes them to its co-enzyme NAD to form NADH.

Question 14

What does the acetyl group combine with during aerobic respiration and what does this produce (1)

Answer 14

The acetyl group combines with co-enzyme A to form acetyl co-enzyme A.

Question 15

What does acetyl co-enzyme A combine with and what does this form (1)

Answer 15

Acetyl co-enzyme A combines with oxaloacetate to form citrate.

Question 16

What happens to the citrate in the citric acid cycle? (1)

Answer 16

During a series of enzyme controlled steps, citrate is gradually converted back into oxaloacetate which results in the generation of a small amount of ATP, NADH and release of CO2.

Question 17

Where does the citric acid cycle occur (1)

Answer 17

In the matrix of the mitochondria.

Question 18

Name the steps in the citric acid cycle (5)

Answer 18

Acetyl co-enzyme A added to oxaloacetate to form Citrate; The citrate undergoes many steps- ADP forms ATP ; the release of CO2; 3NAD takes Hydrogen ions to form 3NADH; FAD becomes FADH2.

Question 19

Where does the electron transport chain occur (1)

Answer 19

In the inner membrane of a mitochondrion.

Question 20

What happens in the electron transport chain

Answer 20

NADH produced during the citric acid cycle releases the hydrogen ions; The electrons from these pushed down the chain releasing energy which is used to pump hydrogen ions across the inner membrane; The return flow of hydrogen ions drives the membrane to produce the bulk of the ATP generated by cellular respiration; The final electron acceptor is oxygen which combines with hydrogen ions and low energy electrons to form water. E+H+O2=H20 (Water)