S10 Hard - Glycolysis
23 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the function of Phosphofructokinase-1 in glycolysis?

  • To synthesize glycogen
  • To regulate anaerobic fermentation
  • To break down glycogen
  • The first committed step in the catabolic pathway of glycolysis (correct)
  • Pyruvate kinase is activated by ATP.

    False

    What is the significance of the ATP/AMP ratio in the regulation of glycolysis?

    The ATP/AMP ratio reflects the energy state of the cell.

    The accumulation of lactic acid is reflected by inhibition of PFK-1 by _______________________ pH.

    <p>low</p> Signup and view all the answers

    Match the following enzymes with their functions in glycolysis:

    <p>Phosphofructokinase-1 = First committed step in glycolysis Pyruvate kinase = Regulated by ATP and alanine</p> Signup and view all the answers

    What is the effect of fructose 1,6-bisphosphate on pyruvate kinase?

    <p>Activates pyruvate kinase</p> Signup and view all the answers

    Glycogen breakdown is regulated by PFK-1.

    <p>False</p> Signup and view all the answers

    What is the function of AMP in the regulation of PFK-1?

    <p>AMP activates PFK-1.</p> Signup and view all the answers

    What is the result of the binding of phosphate groups to the active sites of enzymes?

    <p>Lowers the activation energy</p> Signup and view all the answers

    The phosphorylation of glucose is an essentially reversible reaction under physiological conditions.

    <p>False</p> Signup and view all the answers

    What is the name of the enzyme that phosphorylates glucose in the first step of glycolysis?

    <p>Hexokinase</p> Signup and view all the answers

    The conversion of glucose 6-phosphate to fructose 6-phosphate is catalyzed by the enzyme _______________.

    <p>Phosphohexose Isomerase</p> Signup and view all the answers

    How many ATP are consumed for each molecule of glucose that passes through the preparatory phase of glycolysis?

    <p>2</p> Signup and view all the answers

    The phosphorylation of glucose increases the specificity of the enzymatic reactions.

    <p>True</p> Signup and view all the answers

    Match the following enzymes with their corresponding reactions in glycolysis:

    <p>Hexokinase = Phosphorylation of glucose Phosphohexose Isomerase = Conversion of glucose 6-phosphate to fructose 6-phosphate</p> Signup and view all the answers

    What is the product of Step #10 in glycolysis?

    <p>Pyruvate</p> Signup and view all the answers

    The standard free energy of hydrolysis of the phosphate groups of the reactant in Step #9 is -61.9 kJ/mol.

    <p>False</p> Signup and view all the answers

    What is the name of the enzyme that transfers the high-energy phosphoryl group from the carboxyl group to ADP, forming ATP and 3-phosphoglycerate?

    <p>Phosphoglycerate kinase</p> Signup and view all the answers

    In Step #8, 3-phosphoglycerate is converted to _______________________.

    <p>2-phosphoglycerate</p> Signup and view all the answers

    Match the following compounds with their corresponding steps in glycolysis:

    <p>3-phosphoglycerate = Step #8 Phosphoenolpyruvate = Step #9 Pyruvate = Step #10</p> Signup and view all the answers

    What is the result of the loss of the water molecule in Step #9?

    <p>Generation of a high-energy phosphate compound</p> Signup and view all the answers

    The reaction in Step #10 is reversible.

    <p>False</p> Signup and view all the answers

    What is the name of the form of pyruvate that is more stable at pH 7?

    <p>Keto form</p> Signup and view all the answers

    Study Notes

    Glycolysis: Preparatory Phase

    • For each molecule of glucose that passes through the preparatory phase, two molecules of glyceraldehyde 3-phosphate are formed and two ATP are consumed.

    Phosphorylation of Glucose

    • Glucose is phosphorylated at C-6 to yield glucose 6-phosphate using ATP as the phosphoryl donor.
    • This step is essentially irreversible under physiological conditions.

    Conversion of Glucose 6-phosphate to Fructose 6-phosphate

    • Phosphohexose isomerase catalyzes the reversible isomerization of glucose 6-phosphate (an aldose) to fructose 6-phosphate (a ketose).

    Phosphofructokinase-1 (PFK-1)

    • PFK-1 is the most important regulatory point and the first committed step in the catabolic pathway of glycolysis.
    • The activity of PFK-1 increases when ATP is low.

    Regulation of Phosphofructokinase

    • PFK-1 is inhibited by ATP (allosteric inhibition) and activated by AMP (allosteric activation).
    • PFK-1 is also inhibited by low pH, reflecting lactic acid accumulation due to anaerobic respiration.

    Phosphoglycerate Kinase

    • Phosphoglycerate kinase transfers the high-energy phosphoryl group from the carboxyl group to ADP, forming ATP and 3-phosphoglycerate.

    Conversion of 3-Phosphoglycerate to 2-Phosphoglycerate

    • 3-Phosphoglycerate is converted to 2-phosphoglycerate, involving a conformational change.

    Dehydration of 2-Phosphoglycerate to Phosphoenolpyruvate

    • 2-Phosphoglycerate is dehydrated to form phosphoenolpyruvate, generating a super high-energy phosphate compound.

    Transfer of the Phosphoryl Group from PEP to ADP

    • This step is also an important site of regulation and marks the end of glycolysis, producing pyruvate.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    This quiz covers the binding of phosphate groups to enzymes, activation energy, and specificity of enzymatic reactions in the context of glycolysis.

    More Like This

    Glucólisis completar
    29 questions

    Glucólisis completar

    AdventurousDenver avatar
    AdventurousDenver
    Glycolysis and Hexokinase Enzymes
    10 questions
    Metabolism: Glycolysis Steps Flashcards
    11 questions
    Use Quizgecko on...
    Browser
    Browser