Biochemistry Lecture 23: Glycolysis and Gluconeogenesis
48 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 glycosidic bond primarily associated with?

  • Protein structure
  • Nucleic acid binding
  • Lipid metabolism
  • Carbohydrate structure (correct)

    • Which of the following lectures focuses on the structure of membranes?

  • Carbohydrates in cell-cell interactions
  • Transporters, ion channels, receptors
  • Lipid structure: fatty acids, phospholipids, sphingolipids
  • Membranes and membrane proteins (correct)

    • What subject is covered in the session after 'Enzyme structure and specificity'?

  • Regulation of enzyme activity
  • Mechanisms of rate enhancement (correct)
  • Enzymes Inhibition
  • Transport mechanisms in cells

    • What is the primary role of the glycolytic pathway in metabolism?

    <p>To convert glucose into usable energy</p> Signup and view all the answers

    What type of fats are characterized by a hydrocarbon chain and a carboxylic acid group?

    <p>Fatty acids</p> Signup and view all the answers

    Which of the following is a primary focus during the discussion on 'Enzymes as targets in disease'?

    <p>Inhibition of enzyme action</p> Signup and view all the answers

    What is a crucial function of NAD+ in glycolysis?

    <p>To receive electrons during fermentation</p> Signup and view all the answers

    During which session are carbohydrates discussed in relation to cell-cell interactions?

    <p>Carbohydrates in cell-cell interactions, proteoglycans, bacterial cell wall</p> Signup and view all the answers

    Which of the following statements about ATP generation in glycolysis is true?

    <p>A net gain of ATP occurs through substrate-level phosphorylation.</p> Signup and view all the answers

    Which type of biomolecule is cholesterol categorized under?

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

    Gluconeogenesis primarily occurs in which organ?

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

    What is the primary topic of the session on November 4th?

    <p>Introduction to metabolism</p> Signup and view all the answers

    What is the main purpose of the regeneration of NAD+ during fermentation?

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

    What is generated as a byproduct of anaerobic fermentation in glycolysis?

    <p>Lactic acid or ethanol</p> Signup and view all the answers

    How is gluconeogenesis powered within a cell?

    <p>By ATP and GTP hydrolysis</p> Signup and view all the answers

    Which chapter from 'Stryer, Biochemistry' outlines the glycolytic pathway?

    <p>Chapter 16</p> Signup and view all the answers

    What is the primary location in the body where gluconeogenesis occurs?

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

    Which process is characterized by the hydrolysis of four ATP and two GTP molecules?

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

    What commonly serves as a starting point for gluconeogenesis?

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

    What is the primary role of ATP in the cell?

    <p>To drive energy-requiring processes</p> Signup and view all the answers

    Where does the final step of converting pyruvate to acetyl groups occur?

    <p>In mitochondria</p> Signup and view all the answers

    What effect does the balance between glycolysis and gluconeogenesis have on glucose levels?

    <p>Synthesizes glucose when energy reserves are high</p> Signup and view all the answers

    What type of energy input do the bypass reactions in gluconeogenesis require?

    <p>Chemical energy in the form of ATP and GTP</p> Signup and view all the answers

    What byproduct is produced alongside NADH during the reactions involving acetyl CoA?

    <p>Water and carbon dioxide</p> Signup and view all the answers

    Which organelles are specifically mentioned as being capable of digesting large molecules within cells?

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

    How does the liver respond when energy reserves are low?

    <p>Increases gluconeogenesis</p> Signup and view all the answers

    Which metabolic intermediate indicates sufficient energy reserves in the liver?

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

    In which part of the cell does oxidative phosphorylation primarily occur?

    <p>In mitochondria</p> Signup and view all the answers

    What is the relationship between gluconeogenesis and glycolysis?

    <p>They are regulated to balance glucose consumption and synthesis.</p> Signup and view all the answers

    What is mainly produced in Stage 1 of ATP formation?

    <p>Large amounts of ATP</p> Signup and view all the answers

    What role does oxygen play in the reactions involving acetyl?

    <p>It is required for aerobic respiration</p> Signup and view all the answers

    What is the main function of the reducing power expressed as NADH in cellular processes?

    <p>To drive ATP synthesis</p> Signup and view all the answers

    What is the primary function of gluconeogenesis?

    <p>To generate glucose from pyruvate</p> Signup and view all the answers

    Which steps in glycolysis are bypassed during gluconeogenesis?

    <p>Steps 1, 3, and 10</p> Signup and view all the answers

    What does gluconeogenesis require in terms of energy?

    <p>It requires input of energy</p> Signup and view all the answers

    What is the role of fructose 1, 6-bisphosphate in the context of glycolysis?

    <p>It is cleaved to form two 3-carbon sugars</p> Signup and view all the answers

    Which enzyme is specifically associated with gluconeogenesis?

    <p>Fructose 1, 6-bisphosphatase</p> Signup and view all the answers

    Which of the following statements is true regarding gluconeogenesis?

    <p>It creates two energy carriers for each glucose produced</p> Signup and view all the answers

    Which molecule is a substrate for gluconeogenesis?

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

    What type of protein is associated with glucose 6-phosphatase to enhance its activity?

    <p>Ca2+-binding stabilizing protein</p> Signup and view all the answers

    What is the overall change in Gibbs free energy (ΔG°') for gluconeogenesis?

    <p>248 kJ mol⁻¹ (211 kcal mol⁻¹)</p> Signup and view all the answers

    How many ATP equivalents are utilized in the process of gluconeogenesis when converting pyruvate to glucose?

    <p>6</p> Signup and view all the answers

    What is the stoichiometry of gluconeogenesis involving pyruvate?

    <p>1 glucose + 4 ADP + 2 GDP + 1 NAD + 6 Pi + 2 H</p> Signup and view all the answers

    What by-products are produced during the reversal of glycolysis?

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

    Which process has a lower Gibbs free energy change when converting pyruvate to glucose?

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

    Which of the following statements about glucose synthesis from pyruvate is true?

    <p>It requires the input of energy.</p> Signup and view all the answers

    In terms of energy cost, what is a significant aspect of gluconeogenesis compared to glycolysis?

    <p>Gluconeogenesis requires hydrolysis of high-phosphoryl-transfer-potential molecules.</p> Signup and view all the answers

    What is produced alongside glucose during gluconeogenesis from pyruvate?

    <p>ADP and Pi</p> Signup and view all the answers

    Study Notes

    Lecture 23: Glycolysis and Gluconeogenesis

    • Glycolysis is an anaerobic pathway, occurring before oxygen was abundant.
    • Glycolysis does not require oxygen.
    • Glycolysis converts glucose to pyruvate.
    • The process has many steps, each catalyzed by a different enzyme.
    • Glycolysis has two phases: the energy investment phase and the energy generation phase.
    • The energy investment phase takes up two ATP molecues and the energy generation phase produces four, yielding a net gain of 2 ATP.
    • NAD+ is crucial for glycolysis, as it is required for the conversion of glyceraldehyde 3-phosphate to 1,3-bisphosphoglycerate.
    • Pyruvate has several fates, including fermentation or oxidation to produce more ATP.
    • Gluconeogenesis is the process that replenishes blood glucose, creating glucose from non-carbohydrate molecules like lactate or amino acids.
    • Gluconeogenesis is not a simple reversal of glycolysis, but it uses several different enzymes for the 3 key irreversible steps of glycolysis.

    Metabolic Pathways

    • Key metabolic pathways include glycolysis, the citric acid cycle, and oxidative phosphorylation, each critical for energy production and biosynthesis.
    • Metabolic pathways are a series of linked reactions in which components are systematically built or broken down.
    • ATP is an energy currency, linking energy-releasing pathways with energy-requiring pathways.

    Glucose as a Fuel

    • Almost all organisms use glucose for fuel.
    • In mammals, glucose is the primary fuel for the brain and red blood cells under non-starvation conditions.
    • Glucose's stability as a hexose, combined with its availability from prebiotic conditions, likely contributed to its crucial role in metabolism across all life forms.
    • Glucose is the most stable hexose and is readily available for biochemical processes.

    Glycolysis Steps

    • Detailed steps converting glucose to pyruvate are outlined, focusing on enzymes and high energy connections.
    • Each step in glycolysis is facilitated by a specific enzyme.
    • Specific intermediates in glycolysis are vital for energy production and overall metabolic control.

    Pyruvate's Fates

    • Pyruvate can undergo fermentation (alcoholic or lactic acid).
    • Pyruvate can be completely oxidized through pyruvate processing and the citric acid cycle. Fermentation occurs without oxygen.
    • Oxidizing pyruvate to acetyl CoA occurs specifically in the presence of oxygen.

    Gluconeogenesis

    • The process of creating glucose from non-carbohydrate sources is called gluconeogenesis.
    • Gluconeogenesis is required for maintaining blood glucose levels.
    • Gluconeogenesis bypasses the three irreversible steps of glycolysis. Many of the steps in gluconeogenesis are the reverse of glycolysis.

    Key Scientists

    • Louis Pasteur, Eduard Buchner were pioneers in understanding fermentation and early glycolysis processes.
    • Sir Arthur Harden and William John Young elucidated critical aspects of the reactions.
    • Otto Meyerhof and Jakub Karol Parnas and Gustav Embden were responsible for linking multiple aspects of the reactions.

    Studying That Suits You

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

    Quiz Team

    Related Documents

    Lecture 2. Glycolysis and Gluconeogenesis PDF

    Description

    This quiz focuses on Lecture 23, covering the key processes of glycolysis and gluconeogenesis. Understand the stages of glycolysis, the importance of NAD+, and the distinct mechanisms involved in gluconeogenesis. Test your knowledge of these fundamental metabolic pathways.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser