The Glycolytic Pathway Flashcards
What is Glycolysis?
Sequence of reactions converting glucose to pyruvate with the production of ATP.
In what part of the cell does glycolysis occur?
Cytosol of cell as the enzymes are in a free solution therefore they can transfer from one enzyme to another.
What are the three main stages of glycolysis?
- Conversion of glucose –> fructose 1, 6 diphosphate
- Conversion of fructose 1, 6 diphosphate –>3-c intermediates.
- Formation of pyruvate from 3-c intermediates
How does glucose enter the blood?
Glucose molecule is polar therefore the movement across membranes must be facilitated by transporter proteins such as GLUT1-4
Describe stage 1 of glycolysis.
Conversion of glucose –> fructose 1, 6 diphosphate
Glucose is phosphorylated by the enzyme Hexokinase, resulting in the consumption of one ATP molecule and the production of Glucose-6-phosphate.
Describe stage 2 of glycolysis.
Conversion of Glucose-6-phosphate –> fructose 1,6 phosphate.
The enzyme phosphoglucose isomerase (PI) turns G6P into F16P.
Describe stage 3 of glycolysis.
Fructose-6-phosphate is converted to fructose- 1,6-bisphosphate.
Phosphofructokinase catalyses reaction by using another ATP molecule, a magnesium atom is involved to help shield negative charges.
Describe stage 4 of glycolysis.
Aldolase catalyses the cleavage of fructose- 1,6-bisphosphate to yield two 3-carbon molecules. The enzyme Triose phosphate isomerase rapidly inter-converts the molecules DHAP + GAP.
Describe stage 5 of glycolysis.
Triose phosphate isomerase produces NADH and then adds a phosphate producing 1, 3-bisphosphoglycerate
Describe stage 6 of glycolysis.
Phosphoglycerokinase transfers a P from 1,3-bisphosphoglycerate to a molecule of ADP to form ATP
Describe stage 7 go glycolysis.
The enzyme pyruvate kinase transfers a P from phosphoenolpyruvate to ADP to form pyruvate and ATP.
