Steps of Glycolysis

Question 1

what is the first step of Glycolysis catalyzed by

Answer 1

hexokinase

Question 2

hexokinase

Answer 2

an enzyme w broad specificity that catalyzes the phosphorylation of six carbon sugar

Question 3

how does hexokinase phosphorylate glucose?

Answer 3

by using ATP as the source of phosphate reducing a more relative form of glucose.

Question 4

what does hexokinase phosphorylate prevent

Answer 4

Prevents the phosphorylated glucose molecule from continuing to interact w/ GLUT proteins and it can no longer leave the cell because the negatively charged phosphate will not allow it cross the hydrophic interior of plasma

Question 5

step 2 of glycolysis

Answer 5

an isomerase converts glucoe-6-phosphate into one of its isomers fructose -6-phosphate

Question 6

what is an isomerase

Answer 6

an enzyme that catalyzes the conversion of molecule into one of its isomers

Question 7

step 3 of glycolysis

Answer 7

phosphorylation of fructose -6- phosphate, catalyzed by the enzyme phosphofructokinase.

Question 8

phosphofructokinase

Answer 8

a rate limiting enzyme

Question 9

what is the end product of glucose catabolism

Answer 9

ATP

Question 10

Step 4 glycolysis

Answer 10

employs an enzyme, aldolase, to cleave fructose-1, 6 biphosphate into two three carbon isomers. Dihydroxyacetone phosphate and glyceraldehyde 3 phosphate.

Question 11

step 5 of glycolysis

Answer 11

an isomerase transforms the dihydroxyacetone-phosphate into its isomer, glyceraldehyde-3-phosphate. Thus, the pathway will continue with two molecules of a glyceraldehyde-3-phosphate. At this point in the pathway, there is a net investment of energy from two ATP molecules in the breakdown of one glucose molecule.

Question 12

step 6 glycolysis

Answer 12

oxidizes the sugar (glyceraldehyde-3-phosphate), extracting high-energy electrons, which are picked up by the electron carrier NAD+, producing NADH.

Question 13

step 7 of glycolysis

Answer 13

catalyzed by phosphoglycerate kinase (an enzyme named for the reverse reaction), 1,3-bisphosphoglycerate donates a high-energy phosphate to ADP, forming one molecule of ATP. (This

Question 14

step 8 of glycolysis

Answer 14

the remaining phosphate group in 3-phosphoglycerate moves from the third carbon to the second carbon, producing 2-phosphoglycerate (an isomer of 3-phosphoglycerate). The enzyme catalyzing this step is a mutase (isomerase).

Question 15

step 9 of glycolysis

Answer 15

Enolase catalyzes the ninth step. This enzyme causes 2-phosphoglycerate to lose water from its structure; this is a dehydration reaction, resulting in the formation of a double bond that increases the potential energy in the remaining phosphate bond and produces phosphoenolpyruvate (PEP).

Question 16

step 10 of glycolysis

Answer 16

The last step in glycolysis is catalyzed by the enzyme pyruvate kinase (the enzyme in this case is named for the reverse reaction of pyruvate’s conversion into PEP) and results in the production of a second ATP molecule by substrate-level phosphorylation and the compound pyruvic acid (or its salt form, pyruvate).

Question 17

how many pyruvate molecule does glycolysis produce.

Answer 17

two

Question 18

how many ATP molecule does glycolysis produce.

Answer 18

four

Question 19

how many NADH molecule does glycolysis produce.

Answer 19

two

Question 20

what happens if a cell cannot catabolize pyruvate

Answer 20

it will harvest only two ATP molecules from one molecule of glucose.