[12.1] glycolysis Flashcards
what are the 4 stages of respiration?
- glycolysis
- link reaction
- krebs cycle
- oxidative phosphorylation
what is the purpose of glycolysis?
a hexose sugar (usually glucose) is split into two molecules of the 3-carbon molecule, pyruvate
what are the 4 stages of glycolysis?
- phosphorylation of glucose into glucose phosphate
- splitting of the two phosphorylated glucose
- oxidation of triose phosphate
- production of ATP
what occurs during the 1st step of glycolysis?
before it can be split into two, glucose must first be made more reactive by adding 2 phosphate molecules (phosphorylation)
where do the phosphate molecules required for phosphorylation come from?
hydrolysis of two molecules of ATP to ADP + Pi
what does energy produced during hydrolysis of ATP in phosphorylation do?
- energy is provided to activate glucose
- lowers the activation energy for the enzyme-controlled reactions that follow
what occurs during the 2nd step of glycolysis?
each glucose molecule is split into two 3-carbon molecules known as triose phosphate
what occurs during the 3rd step of glycolysis?
hydrogen is removed from each of the 2 triose phosphate molecules and transferred to a hydrogen-carrier molecule (NAD) to for reduced NAD
what occurs during the 4th step of glycolysis?
- enzyme-controlled reactions convert each triose phosphate into another 3-carbon molecule called pyruvate
- in the process two molecules of ATP are regenerated from ADP
describe the 5 reactions involved in glycolysis
- glucose + 2ATP -> phosphorylated glucose
- phosphorylated glucose -> 2 triose phosphate
- 4H + 2NAD -> 2NADH + 2H⁺
- 4Pi + 4ADP -> 4ATP
- 2 triose phosphate -> 2 pryuvate
what are the products formed from 1 molecule of glucose in glycolysis?
- two molecules of ATP
- two molecules of reduced NAD
- two molecules of pyruvate
