S10 Medium - Glycolysis
24 Questions
2 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 primary usage of ethanol produced through anaerobic fermentation?

  • Biofuel
  • Alcoholic beverages
  • Bread rising
  • All of the above (correct)
  • Lactate produced in muscles during physical activity is converted back to glucose in the liver.

    True

    What enzyme is used by the body to metabolize ethanol?

    alcohol dehydrogenase

    Lactate is converted to _______________ in the liver.

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

    What type of fermentation is used to produce ethanol?

    <p>Anaerobic fermentation</p> Signup and view all the answers

    Glycolysis is more energy-efficient than anaerobic fermentation.

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

    Match the following sugars with their breakdown products:

    <p>Lactose = Glucose and Galactose Fructose = Glucose Glucose = Glucose</p> Signup and view all the answers

    What is the energy efficiency of anaerobic fermentation compared to glycolysis?

    <p>not so much</p> Signup and view all the answers

    What happens when NADPH accumulates in the cell?

    <p>It inhibits the first enzyme in the PPP pathway</p> Signup and view all the answers

    The non-oxidative phase of the PPP is necessary for generating NADPH.

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

    What is the result of NADPH inhibiting the first enzyme in the PPP pathway?

    <p>This results in more glucose 6-phosphate being available for glycolysis. The cell is then able to use glycolysis to generate energy instead of going through the PPP pathway.</p> Signup and view all the answers

    The ______ barked

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

    What is the function of the PPP pathway in an active muscle cell?

    <p>To make ribose for nucleotide synthesis</p> Signup and view all the answers

    Glycolysis is a feeder pathway for the PPP.

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

    Match the following terms with their descriptions:

    <p>Glycolysis = Breakdown of glucose to pyruvate PPP = Generation of NADPH and 5-carbon sugars Gluconeogenesis = Synthesis of glucose from pyruvate</p> Signup and view all the answers

    What is the purpose of the oxidative phase of the PPP in an active muscle cell?

    <p>The oxidative phase of the PPP generates NADPH, which is needed in tissues that are generating NADPH, because the oxidative phase would generate more 5C sugars than the cell needs.</p> Signup and view all the answers

    What is the net balance of glycolysis?

    <p>Glucose + 2 NAD+ + 2 ADP + 2 Pi → 2 Pyruvate + 2 NADH + 2 H+ + 2 ATP + 2 H2O</p> Signup and view all the answers

    In aerobic conditions, NADH is reoxidized to NAD+ by transfer of electrons to the respiratory chain in the mitochondrion.

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

    What is the purpose of lactate dehydrogenase in lactate fermentation?

    <p>Lactate dehydrogenase uses up NADH to reduce the carbonyl of pyruvate to lactate.</p> Signup and view all the answers

    In yeast, pyruvate is fermented to _________________.

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

    Match the following compounds with their respective products in fermentation:

    <p>Glucose = Pyruvate Pyruvate = Lactate Lactate = Ethanol Ethanol = Glucose</p> Signup and view all the answers

    What is the fate of pyruvate in human fermentation?

    <p>It is converted to lactate</p> Signup and view all the answers

    Under aerobic conditions, glycolysis cannot continue because NADH cannot be reoxidized to NAD+.

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

    What is the purpose of regenerating NAD+ from NADH in glycolysis?

    <p>To allow glycolysis to continue.</p> Signup and view all the answers

    Study Notes

    Energy Metabolism

    • During short bursts of physical activity, lactate is produced in muscles and transported to the liver, where it's converted back to glucose.

    Cori Cycle

    • In the liver, an enzyme converts lactate into pyruvate, then into glucose.
    • This process is not as efficient as glucose production.

    Fermentation

    • Fermentation is used to make alcoholic beverages, industrial ethanol, and CO2 for bread to rise.
    • In the body, alcohol dehydrogenase is used to metabolize ethanol into acetaldehyde, which is further metabolized.

    Anaerobic Fermentation

    • Not as energy-efficient as aerobic respiration.

    Glycolysis

    • Glucose + 2 ATP + 2 NAD+ + 4 ADP + 2 Pi → 2 Pyruvate + 2 ADP + 2 NADH + 2 H+ + 4 ATP + 2 H2O (net balance)
    • To continue glycolysis, organisms must reoxidize NADH back to NAD+.

    Fate of Pyruvate

    • Pyruvate can be fermented into lactate or ethanol, regenerating NAD+ from NADH.
    • Human cells ferment pyruvate into lactate, while yeast ferments it into ethanol.

    Lactate Fermentation and Cori Cycle

    • Under hypoxic or anaerobic conditions, NADH generated by glycolysis cannot be reoxidized by O2.
    • Lactate dehydrogenase reduces pyruvate to lactate, using up NADH.

    Non-oxidative Phase of PPP Reactions

    • PPP reactions are needed in tissues generating NADPH.
    • Non-oxidative phase shuffles 5C sugars to 2 6C sugars and glyceraldehyde 3-p.

    Metabolic Control of PPP by NADPH

    • NADPH regulates the partitioning of glucose 6-phosphate between glycolysis and the PPP.
    • When NADPH accumulates, it inhibits glucose-6-phosphate dehydrogenase, diverting glucose 6-phosphate to glycolysis.

    Pathway Integration in an Active Muscle Cell

    • During exercise, glucose is metabolized through glycolysis, with pyruvate converted to lactate or used for energy production.
    • The Cori cycle is an important pathway for lactate produced in muscles, which is then converted back to glucose in the liver.

    Studying That Suits You

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

    Quiz Team

    Description

    Understand how lactate is produced and converted during short bursts of physical activity in the Cori cycle. Learn about muscle metabolism and saccharide transportation.

    More Like This

    Cori Cycle and Energy Production
    59 questions
    Cori Cycle and Metabolism Overview
    59 questions
    Cori Cycle and Gluconeogenesis Quiz
    5 questions
    Use Quizgecko on...
    Browser
    Browser