Glycolysis Flashcards
Where does glycolysis occur?
the cytoplasm of all living cells
Give an overview of the process
6-carbon molecule is split into two 3-carbon molecules called pyruvate
What are the four stages of glycolysis?
activation of glucose by phosphorylation
splitting of the phosphorylated glucose
oxidation of triose phosphate
the production of ATP
What is the activation of glucose by phosphorylation?
two phosphate molecules are added to glucose (come from the hydrolysis of two ATP molecules to ADP)
this provides the energy to activate glucose as it lowers the activation energy for the enzyme controlled reactions
What is the splitting of the phosphorylated glucose?
each glucose molecule is split into two 3-carbon molecules known as triose phosphate
What is the oxidation of triose phosphate?
hydrogen is removed from each of the triose phosphate molecules and transferred to a hydrogen carrier molecule (NAD) to form NADH
What is the production to ATP?
enzyme-controlled reactions convert triose phosphate into pyruvate
2 molecules of ATP are regenerated from ADP
Why is the net yield of ATP only 2 molecules?
4 are made but 2 are used up in the reaction in the phosphorylation of glucose
What are the final yields from glycolysis?
2 molecules of ATP
2 molecules of NADH
2 molecules of pyruvate
What can pyruvate be converted into in the absence of oxygen?
lactate or ethanol through anaerobic respiration - necessary in order to re-oxidise NAD so glycolysis can continue
