7.2 Glycolysis: The Splitting of Sugar

Question 1

what is the most common fuel molecule in animals, plants, and microbes?

Answer 1

glucose -the starting molecule of glycolysis, results in the partial oxidation of glucose and the synthesis of a relatively small amount of ATP and reduced electron carriers

Question 2

glycolysis means:

Answer 2

“splitting sugar”-the 6-carbon sugar is split into two 3-carbon molecules

Question 3

the process of glycolysis is:

Answer 3

anaerobic because oxygen is not consumed

Question 4

glycolysis the probably the most widespread metabolic pathway among organisms because:

Answer 4

it occurs in nearly all living organisms

Question 5

glycolysis begins with a molecule of glucose and produces:

Answer 5

two 3-carbon molecules of pyruvate and a net total of two molecules of ATP and two molecules of the electron carrier NADH

Question 6

the ATP produced in glycolysis produced directly by:

Answer 6

substrate-level phosphorylation

Question 7

glycolysis is a series of:

Answer 7

10 chemical reactions which can be divided into three phases

Question 8

outline the first phase of glycolysis

Answer 8

prepares glucose for the next two phases by adding two phosphate groups to glucose, requires an input of energy, two molecules of ATP are hydrolyzed per molecule of glucose (first phase is an ENDERGONIC PROCESS)

Question 9

the phosphorylation of glucose in phase 1 of glycolysis has two important consequences:

Answer 9

phosphorylated glucose is trapped inside the cell (cannot pass through membrane transporters) and the presence of two negatively charged phosphate groups in close proximity destabilizes the molecule so that it can be broken apart in the second phase

Question 10

outline the second phase of glycolysis:

Answer 10

the “cleavage” phase-6-carbon molecule is split into two 3-carbon molecules.

Question 11

outline the third and final phase of glycolysis:

Answer 11

the “payoff” phase because ATP and the electron carrier NADH is produced, later NADH will contribute to the synthesis of ATP during oxidative phosphorylation. phase ends with the production of two molecules of pyruvate

Question 12

glycolysis beings with a single molecule of glucose (six carbons) and produces:

Answer 12

two molecules of pyruvate (3C each) and yields 4 molecules of ATP and 2 molecules of NADH. however, 2 ATP is consumed during phase one, so net gain is 2 ATP and 2 NADH