Glycolysis Flashcards
What is Glycolysis?
The initial stage of both aerobic and anaerobic respiration
Where does glycolysis occur?
In the cytoplasm of all living cells
In brief, what happens in glycolysis?
A hexose sugar (6C) is split into two molecules of pyruvate (3C)
What are the four stages of glycolysis?
- Phosphorylation of glucose to glucose phosphate
- Splitting of the phosphorylated glucose
- Oxidation of triose phosphate
- Production of ATP
(Glycolysis) How does the phosphorylation of glucose to glucose phosphate take place?
Glucose is first made reactive by adding two phosphate molecules in the process of phosphorylation
(Glycolysis) Where do the phosphate molecules come from to phosphorylate the glucose?
The hydrolysis of two ATP molecules to ADP
(Glycolysis) What does making the glucose reactive do to the activation energy?
It lowers it
(Glycolysis) What does the phosphorylated glucose split into?
Each phosphorylated glucose splits into two 3-carbon molecules known as triose phosphate
(Glycolysis) What happens to the triose phosphate?
It is oxidised (hydrogen is removed)
(Glycolysis) What happens to the removed hydrogen from the triose phosphate molecules?
It is transferred to the hydrogen carrier NAD to form reduced NAD
(Glycolysis) How is ATP produced?
Each triose phosphate is converted into pyruvate and in the the process, two molecules of ATP are regenerated
(Glycolysis) What is the overall yield from one molecule of glucose?
- two molecules of ATP
- two molecules of reduced NAD
- two molecules of pyruvate
(Glycolysis) Why is the overall yield of ATP two?
Four are produced but two were used in the initial phosphorylation of glucose therefore overall ATP yield is 2
How does glycolysis provide indirect evidence for evolution?
It is universal of every living organism
Why is glycolysis universal?
It requires no organelle or membrane to take place because all enzymes needed are found in the cytoplasm and it can take place whether or not there is oxygen present
