5.7.1 Glycolysis

• What is glycolysis?

  Initial stage of respiration
• What is the net output of ATP in glycolysis per glucose molecule?

  2 ATP
• Which key enzyme is involved in the phosphorylation of glucose to glucose-6-phosphate?

  Hexokinase
• What is the total energy yield from glycolysis in terms of ATP per glucose molecule?

  2 ATP
• What molecule is glucose broken down into during glycolysis?

  Pyruvate
• What is the net gain of NADH during glycolysis per glucose molecule?

  2 NADH
• What molecule is fructose-6-phosphate converted to during glycolysis?

  Fructose-1,6-bisphosphate
• The net gain of ATP and NADH from glycolysis is 2 ATP and 2 NADH per glucose molecule.


  True
• The input to glycolysis includes one molecule of glucose.
• Order the two phases of glycolysis:

  1️⃣ Energy investment

  2️⃣ Energy payoff
• Glycolysis results in a net gain of 2 ATP and 2 NADH
• The energy investment phase of glycolysis produces ATP directly.

  False
• In the energy payoff phase, fructose-1,6-bisphosphate is cleaved by aldolase
• Phosphofructokinase-1 (PFK-1) is a key regulatory enzyme in glycolysis.


  True
• Glyceraldehyde-3-phosphate dehydrogenase produces NADH and 1,3-bisphosphoglycerate by oxidizing GAP
• What is the net ATP production of glycolysis per glucose molecule?

  2 ATP
• Glycolysis occurs in the cytoplasm
• Glycolysis involves two main phases: energy investment and energy payoff.


  True
• ATP is consumed during the investment phase of glycolysis.
• Glycolysis is regulated by feedback inhibition from ATP.

  True
• In step 1 of glycolysis, glucose is phosphorylated to glucose-6-phosphate using ATP.
• Glycolysis consumes 2 ATP but produces 4 ATP, resulting in a net gain of 2 ATP.


  True
• Fructose-1,6-bisphosphate splits into two 3-carbon molecules without consuming or producing ATP.
• Why does glycolysis occur in the cytoplasm rather than within organelles?

  For aerobic and anaerobic respiration
• Match the input and output of glycolysis:

  1 Glucose ↔️ 2 ATP

  2 ATP ↔️ 2 NADH

  2 NAD+ ↔️ 2 Pyruvate
• What are the inputs of glycolysis per glucose molecule?

  1 Glucose, 2 ATP, 2 NAD+
• Arrange the two phases of glycolysis in the correct order.

  1️⃣ Energy investment

  2️⃣ Energy payoff
• Which enzyme catalyzes the phosphorylation of glucose in the energy investment phase?

  Hexokinase
• What is the role of hexokinase in glycolysis?

  Phosphorylates glucose
• Which enzyme cleaves fructose-1,6-bisphosphate into two 3-carbon molecules?

  Aldolase
• Glycolysis occurs in the cytoplasm of the cell.


  True
• In the energy investment phase, two ATP molecules are used to phosphorylate glucose
• In glycolysis, fructose-1,6-bisphosphate is cleaved by the enzyme aldolase
• Match the enzyme with its role in glycolysis:

  Hexokinase ↔️ Phosphorylates glucose to glucose-6-phosphate

  PFK-1 ↔️ Phosphorylates fructose-6-phosphate
• Which enzyme phosphorylates glucose in the first step of glycolysis?

  Hexokinase
• Which enzyme oxidizes glyceraldehyde-3-phosphate, producing NADH?

  GAPDH
• What is the role of ATP in glycolysis?

  Provides immediate energy
• Pyruvate, the final product of glycolysis, enters the Krebs cycle under aerobic conditions.
• Which two enzymes are key in the energy payoff phase of glycolysis?

  Aldolase, GAPDH
• Two ATP molecules are consumed in the energy investment phase of glycolysis.


  True