7 respiration

Question 1

What is the equation for respiration?

Answer 1

Glucose + oxygen —-> water + carbon dioxide

Question 2

Where does glycolysis occur?

Answer 2

Cytoplasm

Question 3

Where does the link reaction occur?

Answer 3

Mitochondrial matrix

Question 4

Where does the krebs cycle occur?

Answer 4

Mitochondrial matrix

Question 5

What does glucose form at the end of glycolysis?

Answer 5

Pyruvate

Question 6

what’s the difference between aerobic and anaerobic respiration?

Answer 6

• aerobic- needs OXYGEN
• no oxygen- basically glycolysis, pyruvate, lactate over and over

Question 7

suggest what would happen in the Krebs cycle if acetyl CoA became unavailable.2

Answer 7

• cycle would stop
• 4 carbon compound accumulates
• 6 carbon compound not made enough, 5 carbon compound will also run short

Question 8

The hydrogen (H) from the Krebs cycle enters the electron transport chain and oxidative phosphorylation occurs.

Explain what is meant by the term oxidative phosphorylation.(3)

Answer 8

• electrons passed along an electron transport chain
• energy lost used to add a phosphate to ADP to form ATP
• H+ move into inter membrane space and will move down the electrochemical gradient via chemiosmosis through ATPsynthase

Question 9

Describe the fate of reduced NAD in aerobic respiration.(4)

Answer 9

• NADH enters mitochondria from glycolysis
• at inner membrane it becomes oxidised to NAD and the etc is reduced gaining electrons
• H+ pumped into inter membrane space
• NAD returns to Krebs cycle

Question 10

what is necessary for respiration or any process to occur?

Answer 10

-specific intracellular ENZYMES which catalyse and control processes

Question 11

what is the net production of glycolysis?

Answer 11

2 x ATP

2 x NADH

2 x pyruvate

Question 12

what are two reasons for phosphorylation?

Answer 12

• keeps glucose inside the cell as the cell membrane is impermeable to sugar phosphate
• makes it unstable and more reactive

Question 13

describe in bullet points the conversion of pyruvate into acetyl coenzyme A. aka LINK REACTION

Answer 13

• CO₂ gas as waste product
• coenzyme A inputted in
• conversion of NAD+ to NADH provides energy (reduction of NAD+)

Question 14

describe the Krebs cycle in bullet points.

Answer 14

• 2C acetyl coenzyme A joins a 4C compound to form a 6C compound
• this gives off a CO2 and becomes 5C, NAD+ to NADH catalyses this (red)
• 5C becomes a 4C giving off another CO2 and an ATP, NAD+ to NADH catalyses this (red)
• FAD+ becomes FADH (red) 4C stays as is
• NAD+ becomes NADH (red) 4C stays as is
• process repeats again all the new reduced electron acceptors move into the mitochondria for the ETC.