Biochem 301 QUIZ 6 test
questions with complete
verified solutions 2025
Why is glucose such a prominent fuel?
It is formed from formaldehyde under prebiotic conditions, so potentially
an revolutionary background.
It is stable in ring formation and does not interfere with other proteins
What is glycolysis?
The sequence of reactions that converts one molecule of glucose into two
molecules of pyruvate while generating ATP.
Which cells use glycolysis?
Common to virtually all cells
How are the enzymes of glycolysis organized?
Into complexes, such as bound in the inner surface of the cell membrane
What does the organization of glycolytic enzymes provide?
Facilitates movements of substrates between enzymes and prevents the
release of toxic intermediates
What are the two "stages" that glycolysis can be thought of?
1) The trapping and preparation phase, where no ATP is generated.
2) ATP is harvested when three-carbon fragments are oxidized to pyruvate
What is the strategy behind Stage 1 of glycolysis?
The glucose is trapped in the cell to form a compound that can be readily
cleaved into phosphorylated, 3-carbon units
What are the TYPES of reactions in Stage 1 of glycolysis?
,Phosphorylation, isomerization, and a second phosphorylation.
Completed with a cleave into two phosphorylated 3-carbon fragments
What is the first step of glycolysis? Which enzyme catalyzes it?
Glucose is phosphorylated by ATP to form glucose 6-phosphate and ADP
Enzyme: Hexokinase
Why is the first step of glycolysis notable?
Glucose 6-phosphate cannot pass through the membrane to the
extracellular side and now it has high phosphoryl-transfer potential
What are kinases? What do kinases require to function?
enzymes that catalyze the transfer of a phosphoryl group from ATP to an
acceptor
Often require Mg2+ or Mn2+
What type of substrate binding model does glucose follow with
hexokinase?
Induced fit, so enzyme moves such that the environment becomes
nonpolar and therefore the ATP phosphoryl group can be easily donated
What is the second step of glycolysis?
What enzyme catalyzes this reaction?
glucose-6-phosphate is isomerized to fructose-6-phosphate
Enzyme: phospohexose isomerase
Why is the second step of glycolysis important?
, Glucose 6-phosphate is not readily cleaved into two three-carbon
fragments, but fructose 6-phosphate is
What is the third step of glycolysis?
Which enzyme catalyzes this step?
Fructose 6-phosphate is phosphorylated by ATP to Fructose 1,6-
biosphosphate.
Enzyme: Phosphofructokinase (PFK-1)
Why is the third step of glycolysis important?
It is irreversible under cellular conditions -- COMMITED STEP
What is the fourth step of glycolysis?
Which enzyme catalyzes this step?
Fructose-1,6-bisphosphate into is cleaved into glyceraldehyde 3-
phosphate and Dihydroxyacetone phosphate
Enzyme: Aldolase
What is important about the products of the fourth step of glycolysis?
Glyceraldehyde 3-phosphate is used along the pathway, while
Dihydroxyacetone phosphate (DHAP) is not.
What is the fifth step of glycolysis?
Which enzyme catalyzes this step?
Dihydroxyacetone phosphate is isomerized to Glyceraldehyde 3-
phosphate.
Enzyme: Triose Phosphate Isomerase
questions with complete
verified solutions 2025
Why is glucose such a prominent fuel?
It is formed from formaldehyde under prebiotic conditions, so potentially
an revolutionary background.
It is stable in ring formation and does not interfere with other proteins
What is glycolysis?
The sequence of reactions that converts one molecule of glucose into two
molecules of pyruvate while generating ATP.
Which cells use glycolysis?
Common to virtually all cells
How are the enzymes of glycolysis organized?
Into complexes, such as bound in the inner surface of the cell membrane
What does the organization of glycolytic enzymes provide?
Facilitates movements of substrates between enzymes and prevents the
release of toxic intermediates
What are the two "stages" that glycolysis can be thought of?
1) The trapping and preparation phase, where no ATP is generated.
2) ATP is harvested when three-carbon fragments are oxidized to pyruvate
What is the strategy behind Stage 1 of glycolysis?
The glucose is trapped in the cell to form a compound that can be readily
cleaved into phosphorylated, 3-carbon units
What are the TYPES of reactions in Stage 1 of glycolysis?
,Phosphorylation, isomerization, and a second phosphorylation.
Completed with a cleave into two phosphorylated 3-carbon fragments
What is the first step of glycolysis? Which enzyme catalyzes it?
Glucose is phosphorylated by ATP to form glucose 6-phosphate and ADP
Enzyme: Hexokinase
Why is the first step of glycolysis notable?
Glucose 6-phosphate cannot pass through the membrane to the
extracellular side and now it has high phosphoryl-transfer potential
What are kinases? What do kinases require to function?
enzymes that catalyze the transfer of a phosphoryl group from ATP to an
acceptor
Often require Mg2+ or Mn2+
What type of substrate binding model does glucose follow with
hexokinase?
Induced fit, so enzyme moves such that the environment becomes
nonpolar and therefore the ATP phosphoryl group can be easily donated
What is the second step of glycolysis?
What enzyme catalyzes this reaction?
glucose-6-phosphate is isomerized to fructose-6-phosphate
Enzyme: phospohexose isomerase
Why is the second step of glycolysis important?
, Glucose 6-phosphate is not readily cleaved into two three-carbon
fragments, but fructose 6-phosphate is
What is the third step of glycolysis?
Which enzyme catalyzes this step?
Fructose 6-phosphate is phosphorylated by ATP to Fructose 1,6-
biosphosphate.
Enzyme: Phosphofructokinase (PFK-1)
Why is the third step of glycolysis important?
It is irreversible under cellular conditions -- COMMITED STEP
What is the fourth step of glycolysis?
Which enzyme catalyzes this step?
Fructose-1,6-bisphosphate into is cleaved into glyceraldehyde 3-
phosphate and Dihydroxyacetone phosphate
Enzyme: Aldolase
What is important about the products of the fourth step of glycolysis?
Glyceraldehyde 3-phosphate is used along the pathway, while
Dihydroxyacetone phosphate (DHAP) is not.
What is the fifth step of glycolysis?
Which enzyme catalyzes this step?
Dihydroxyacetone phosphate is isomerized to Glyceraldehyde 3-
phosphate.
Enzyme: Triose Phosphate Isomerase
