glycolysis

Question 1

summary of aerobic respiration (comparison with anaerobic)

Answer 1

needs oxygen
more efficient (more ATP per molecule of glucose)
complete breakdown of glucose to form CO2 and ATP
Slow
involves the stages glycolysis, link reaction, krebs cycle, oxidative phosphorylation

Question 2

summary of anaerobic respiration

Answer 2

doesn’t need oxygen
less efficient
incomplete breakdown of glucose
makes harmful waste products, animals and bacteria= lactic acid, plants and yeast= ethanol
fast
only glycolysis

Question 3

summary of four stages of aerobic respiration

Answer 3

1. glycolysis- the splitting of the 6 carbon glucose molecule into two 3-carbon pyruvate molecules
2. link reaction- the 3 carbon pyruvate molecules enter a series of reactions which lead to the formation of acetyl coenzyme A (2 carbon molecule)
3. krebs cycle- the introduction of acetyl co enzyme A into a cycle of redox reactions that yield some ATP and a large quantity of reduced NAD and FAD
4. oxidative phosphorylation- the use of electrons associated with NAD and FAD released from the krebs cycle to synthesise ATP with water as a by-product

Question 4

stage 1 of glycolysis

Answer 4

phosphorylation of glucose to glucose phosphate. glucose made more reactive by the addiction of two phosphate molecules which come from the hydrolysis of two ATP molecules to ADP. provides energy to activate glucose and lowers the activation energy for the enzyme controlled reactions that follow

Question 5

stage 2 of glycolysis

Answer 5

splitting of the phosphorylated glucose: each glucose molecule is spout into two 3 carbon molecules known as triose phosphate

Question 6

stage 3 of glycolysis

Answer 6

oxidation of triose phosphate. hydrogen is removed from each triose phosphate molecule and transferred to hydrogen carrier molecule NAD to form NADH

Question 7

stage four of glycolysis

Answer 7

the production of ATP. enzyme controlled reactions convert the triose phosphate into pyruvate (which is then actively transported into mitochondria for link reaction) in this process two molecules of ATP are regenerated from ATP

Question 8

what is the overall yield from one glucose molecule undergoing glycolysis?

Answer 8

•two molecules of ATP (four are produced but two are used in the initial phosphorylation of glucose and so the net increase is two)
•two molecules of reduced NAD (NADH)
• two molecules of pyruvate

Question 9

where are the enzymes for glycolysis found?

Answer 9

they are found in the cytoplasm of cells and so glycolysis doesn’t require any organelle or membrane. also does not require oxygen.