Carbohydrate Metabolism and Classification
26 Questions
1 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

Which of the following polysaccharides is a branched polymer of glucose molecules?

  • Starch
  • Hyaluronic acid
  • Cellulose
  • Glycogen (correct)

    • What is the main structural difference between starch and glycogen?

  • Starch is a linear polymer, while glycogen is branched (correct)
  • Starch is a heteropolysaccharide, while glycogen is a homopolysaccharide
  • Starch is found in plants, while glycogen is found in animals
  • Starch is made up of only glucose units, while glycogen contains other monosaccharides

    • Which of the following is a heteropolysaccharide?

  • Cellulose
  • Glycogen
  • Starch
  • Hyaluronic acid (correct)

    • Which of the following is NOT a function of polysaccharides?

    <p>Hormonal signaling (B)</p> Signup and view all the answers

    What is the primary function of cellulose in plants?

    <p>Structural support (A)</p> Signup and view all the answers

    What is the main function of gluconeogenesis?

    <p>To synthesize glucose from noncarbohydrate precursors. (B)</p> Signup and view all the answers

    Which of the following enzymes in glycolysis is inhibited by ATP?

    <p>Phosphofructokinase (C)</p> Signup and view all the answers

    During the preparatory phase of glycolysis, how many ATP molecules are consumed?

    <p>2 (C)</p> Signup and view all the answers

    Which condition promotes gluconeogenesis?

    <p>Fasted condition (D)</p> Signup and view all the answers

    What is produced during glycolysis from one molecule of glucose?

    <p>2 Pyruvates, 2 ATP, 2 NADH (B)</p> Signup and view all the answers

    Which of the following best defines carbohydrates?

    <p>Hydrosoluble molecules with the empirical formula (CH2O)n. (D)</p> Signup and view all the answers

    What class of carbohydrates consists of 2 to 10 monosaccharide units?

    <p>Oligosaccharides (D)</p> Signup and view all the answers

    Which type of sugar is a hexose monosaccharide?

    <p>Glucose (D)</p> Signup and view all the answers

    What distinguishes aldoses from ketoses in monosaccharides?

    <p>Aldoses have an aldehyde group and ketoses have a ketone group. (A)</p> Signup and view all the answers

    What is the main characteristic of homopolysaccharides?

    <p>They contain the same kind of monosaccharide monomers. (C)</p> Signup and view all the answers

    Which of the following represents an oligosaccharide?

    <p>Lactose (C)</p> Signup and view all the answers

    Which statement is true regarding the structure of carbohydrates?

    <p>Polysaccharides are composed of more than 100 monosaccharides. (D)</p> Signup and view all the answers

    Which of the following is not a function of carbohydrates?

    <p>Buffering acid-base balance (C)</p> Signup and view all the answers

    Which statement correctly describes the Cori cycle?

    <p>It converts lactate to glucose, then glucose to glycogen. (A)</p> Signup and view all the answers

    What is required for gluconeogenesis to form one molecule of glucose from pyruvate?

    <p>4 ATP and 2 GTP (D)</p> Signup and view all the answers

    What is glycogen primarily used for in skeletal muscle?

    <p>Providing glucose during contraction (C)</p> Signup and view all the answers

    Which hormones initiate glycogen breakdown in the liver?

    <p>Glucagon and epinephrine (C)</p> Signup and view all the answers

    During fasting states, which metabolic process occurs?

    <p>Gluconeogenesis (B)</p> Signup and view all the answers

    Which reaction is bypassed in gluconeogenesis compared to glycolysis?

    <p>Conversion of glucose-6-phosphate to glucose (B)</p> Signup and view all the answers

    What activates glycogenesis after a meal?

    <p>Insulin (B)</p> Signup and view all the answers

    What is the main structural characteristic of glycogen?

    <p>Highly branched polymer of glucose (D)</p> Signup and view all the answers

    Flashcards

    Polysaccharides

    Carbohydrates formed by long chains of monosaccharides.

    Homopolysaccharides

    Polysaccharides made up of one type of monosaccharide.

    Heteropolysaccharides

    Polysaccharides containing more than one type of monosaccharide.

    Starch

    A branched polymer of glucose, used for energy storage in plants.

    Signup and view all the flashcards

    Glycogen

    A more branched and compact glucose polymer used for energy storage in animals.

    Signup and view all the flashcards

    Carbohydrates

    Hydrosoluble molecules with empirical formula (CH2O)n.

    Signup and view all the flashcards

    Monosaccharides

    Building blocks of carbohydrates; single sugar units like glucose.

    Signup and view all the flashcards

    Oligosaccharides

    Carbohydrates made of 2 to 10 monosaccharides joined by glycosidic bonds.

    Signup and view all the flashcards

    Disaccharides

    Special case of oligosaccharides consisting of two monosaccharides.

    Signup and view all the flashcards

    Aldoses

    Monosaccharides with an aldehyde group in their structure.

    Signup and view all the flashcards

    Ketoses

    Monosaccharides containing a ketone group instead of an aldehyde.

    Signup and view all the flashcards

    Glycosidic bonds

    Covalent bonds formed between monosaccharides during carbohydrate synthesis.

    Signup and view all the flashcards

    Cori Cycle

    The process where lactate from muscles is converted to glucose in the liver, then returned to muscles to form glycogen.

    Signup and view all the flashcards

    Gluconeogenesis

    The metabolic pathway that generates glucose from non-carbohydrate substrates, bypassing some glycolytic steps.

    Signup and view all the flashcards

    Irreversible reactions in Glycolysis

    Three key steps of glycolysis that cannot be reversed in gluconeogenesis, requiring alternative enzymes.

    Signup and view all the flashcards

    ATP requirement for Gluconeogenesis

    Four ATP and two GTP are needed to form one glucose molecule from pyruvate during gluconeogenesis.

    Signup and view all the flashcards

    Glycogenolysis

    The enzymatic breakdown of stored glycogen to release glucose, activated during physical activity or fasting.

    Signup and view all the flashcards

    Glycogenesis

    The process of converting glucose to glycogen, stimulated by insulin after meals.

    Signup and view all the flashcards

    Metabolism Regulation States

    In the well-fed state, insulin promotes glycogen synthesis; in fasting, glucagon promotes glycogen breakdown and gluconeogenesis.

    Signup and view all the flashcards

    Glycolysis

    The process that breaks down glucose into two pyruvate molecules, generating energy.

    Signup and view all the flashcards

    ATP production in Glycolysis

    Glycolysis produces a net gain of 2 ATP molecules per glucose molecule.

    Signup and view all the flashcards

    Key enzymes in Glycolysis

    Glycolysis is regulated by three key enzymes influenced by activators and inhibitors.

    Signup and view all the flashcards

    Function of Gluconeogenesis

    Provides glucose when glycogen stores are low, especially during fasting or exercise.

    Signup and view all the flashcards

    Study Notes

    Carbohydrate Metabolism

    • Carbohydrates are hydrosoluble molecules with the empirical formula (CH₂O)ₙ. Monosaccharides are the building blocks of larger carbohydrates.
    • Carbohydrates serve various functions, including energy storage, structural roles (like cellulose in plant cell walls), and as components of other molecules (like glycoproteins and DNA).

    Carbohydrate Classification

    • Monosaccharides: Simple sugars, classified based on the carbonyl group (aldehyde or ketone).
      • Aldoses have an aldehyde group.
      • Ketoses have a ketone group.
      • Examples include trioses (3 carbons), tetroses (4 carbons), pentoses (5 carbons), and hexoses (6 carbons) like glucose, fructose, and galactose.
    • Oligosaccharides: Chains of 2-10 monosaccharides linked by glycosidic bonds.
      • Disaccharides, like lactose (galactose + glucose), sucrose (glucose + fructose), and maltose (glucose + glucose), are examples of oligosaccharides.
    • Polysaccharides: Chains of more than 10 monosaccharides.
      • Homopolysaccharides are composed of a single type of monosaccharide unit, such as starch (glucose polymer in plants) and glycogen (branched glucose polymer in animals). Cellulose (unbranched glucose polymer in plants) is another example of a storage form.
      • Heteropolysaccharides are composed of multiple types of monosaccharide units. An example is hyaluronic acid which is found in the synovial fluid and vitreous humor of the eye.

    Digestion of Carbohydrates

    • Polysaccharides and oligosaccharides are broken down into monosaccharides by enzymes in the digestive tract.
    • Specific enzymes, like amylase (breaks down 1-4 bonds), lactase, and sucrase, target different bonds.
    • The resulting monosaccharides are absorbed into the bloodstream.

    Glucose Homeostasis

    • Maintaining stable blood glucose levels (homeostasis) is crucial for energy provision to the brain and other tissues.
    • After a meal, insulin is released, promoting glucose uptake by tissues and glycogen synthesis.
    • During fasting or exercise, glucagon is released, leading to glycogen breakdown and gluconeogenesis (new glucose production).

    Glycolysis

    • The universal central pathway of glucose catabolism (breaking down).
    • Glycolysis converts one molecule of glucose into two molecules of pyruvate in the cytoplasm.
    • During glycolysis, some free energy released from glucose is conserved in the form of ATP and NADH.
    • The pathway is regulated by key enzymes like hexokinase, phosphofructokinase, and pyruvate kinase.

    Gluconeogenesis

    • The pathway for synthesizing glucose from non-carbohydrate precursors, like lactate, glycerol, and some amino acids.
    • Different enzymes in gluconeogenesis bypass irreversible steps in glycolysis.
    • Gluconeogenesis is crucial for maintaining blood glucose levels during fasting.

    Cori Cycle

    • A cyclical process between muscles and the liver.
    • During intense exercise, lactate (product of anaerobic glycolysis) in the muscles is transported to the liver.
    • The liver converts lactate back to glucose via gluconeogenesis and then delivers the glucose back to the muscles, maintaining glycogen stores.

    Glycogen Metabolism

    • Glycogenesis: The synthesis of glycogen from glucose. Insulin stimulates this pathway.
    • Glycogenolysis: The breakdown of glycogen into glucose. Epinephrine and glucagon stimulate this pathway.
    • Glycogen serves as a storage form of glucose in animals, especially in the liver and muscles.
    • Glycogen in muscle is for immediate energy use during contraction.
    • Glycogen in the liver maintains blood glucose levels between meals and during fasting.

    Regulation of Carbohydrate Metabolism

    • Well-fed state: Insulin promotes glycogen synthesis and glucose uptake, and glycolysis.
    • Fasting state: Glucagon promotes glycogenolysis and gluconeogenesis, while low blood glucose stimulates hormonal secretions for glucose production.
    • Exercise: Epinephrine promotes glycogen breakdown and glycolysis in muscle and liver.

    Studying That Suits You

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

    Quiz Team

    Related Documents

    Carbohydrate Metabolism PDF

    Description

    Explore the fascinating world of carbohydrates, their structures, and classifications in this quiz. Understand the differences between monosaccharides, oligosaccharides, and polysaccharides, including their functions in energy storage and cell structure. Test your knowledge on various carbohydrate types and their roles in biological systems.

    More Like This

    Carbohydrate Metabolism Quiz
    60 questions

    Carbohydrate Metabolism Quiz

    WellReceivedMagic avatar
    WellReceivedMagic
    Carbohydrate Metabolism Quiz
    10 questions

    Carbohydrate Metabolism Quiz

    HighQualityAlmandine avatar
    HighQualityAlmandine
    Biochemistry Chapter on Carbohydrates
    50 questions

    Biochemistry Chapter on Carbohydrates

    GenuineSwaneeWhistle avatar
    GenuineSwaneeWhistle
    Carbohydrate Metabolism Overview
    26 questions

    Carbohydrate Metabolism Overview

    ValuablePurple avatar
    ValuablePurple
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser