Question

In glycolysis, 6-C compounds are split into 3-C compounds by enzyme
A)Isomerase
B)Aldolase
C)Hexokinase
D)Dehydrogenase

Answer 1

Glycolysis is the first step within the breakdown of glucose to extract energy for cellular metabolism. Glycolysis consists of an energy-requiring phase followed by an energy-releasing phase.

Complete answer:
Glycolysis is a series of reactions that extract energy from glucose by splitting it into two three-carbon molecules called pyruvates. Living organisms do glycolysis as a part of their metabolism. The method doesn't use oxygen and is anaerobic. Glycolysis takes place within the cytoplasm of both prokaryotic and eukaryotic cells. Glucose enters heterotrophic cells in two ways:
A.Through secondary transport during which the transport takes place against the glucose concentration gradient.
B.Through a bunch of integral proteins called GLUT proteins, also called glucose transporter proteins. These transporters assist within the facilitated diffusion of glucose.

Glycolysis consists of ten steps divided into two distinct halves. The primary half of the glycolysis consists of energy-requiring steps. This pathway traps glucose molecules within the cell and uses energy to change it in order that the six-carbon sugar molecule may be split evenly into the 2 three-carbon molecules. The last half of glycolysis extracts energy from the molecules and stores it within the variety of ATP and NADH, the reduced variety of NAD.

1.In this, glycolysis is catalyzed by hexokinase that catalyzes phosphorylation of six-carbon sugars. Hexokinase phosphorylates glucose producing glucose-6-phosphate.
Within the second step of glycolysis, an isomerase converts glucose-6-phosphate into one amongst its isomers, fructose-6-phosphate. This leads to a split of sugar into two three-carbon molecules.
2.In the third step, phosphorylation of fructose-6-phosphate, catalyzed by the enzyme phosphofructokinase. A second ATP molecule donates a high-energy phosphate to fructose-6-phosphate, producing fructose-1,6-bisphosphate. During this pathway, phosphofructokinase acts as rate-limiting enzyme.
3.The newly added high-energy phosphates further destabilize fructose-1,6-bisphosphate. In this step aldolase enzyme cleaves 1,6-bisphosphate into two 3-C isomers: dihydroxyacetone-phosphate and glyceraldehyde-3-phosphate.
4.In this an isomerase transforms the dihydroxyacetone-phosphate into its isomer, glyceraldehyde-3-phosphate. Thus, the pathway will continue with two molecules of one isomer. At this time within the pathway, there's a net investment of energy from two ATP molecules within the breakdown of 1 glucose molecule.
5.In this oxidation of sugar starts, leading to extraction of high-energy electrons, which are picked up by the electron carrier NAD+, producing NADH. Sugar is phosphorylated by the addition of phosphate groups thus producing 1,3-bisphosphoglycerate.
6.In this step phosphoglycerate kinase, 1,3-bisphosphoglycerate donates a high-energy phosphate to ADP, forming one molecule of ATP. 1,3-bisphosphoglycerate gets oxidized to a group, and 3-phosphoglycerate is made.
7.Within the eighth step, the remaining phosphate group in 3-phosphoglycerate moves from the third carbon to the second carbon, producing 2-phosphoglycerate. The enzyme catalyzing this step could be a mutase.
8.Enolase catalyzes the ninth step. This enzyme causes 2-phosphoglycerate to lose water from its structure; this can be a dehydration reaction, leading to the formation of a covalent bond that increases the potential energy within the remaining phosphate bond and produces phosphoenolpyruvate (PEP).
9.The last step in glycolysis is catalyzed by the enzyme pyruvate kinase and leads to the assembly of a second ATP molecule by substrate-level phosphorylation and also the compound acid.

Hence, the correct answer is option (B)

Note: Glycolysis starts with glucose and ends with two pyruvate molecules, a complete of 4 ATP molecules and two molecules of NADH. Two ATP molecules were used in the primary half of the pathway to arrange the six-carbon ring for cleavage, therefore the cell includes a net gain of two ATP molecules and two NADH molecules for its use.