Digestion: The Breakdown of Food
26 Questions
0 Views

Digestion: The Breakdown of Food

Created by
@ConsideratePyrite

Podcast Beta

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What role does the liver play in the metabolism of glucose?

  • It stores glucose as glycogen. (correct)
  • It uses glucose for immediate energy only.
  • It eliminates excess glucose through the urine.
  • It converts glucose into ethanol.

    • Which of the following substances are primarily absorbed in the large intestine?

  • Sugars and fats
  • Water and mineral salts (correct)
  • Vitamins and amino acids
  • Most undigested protein

    • What is the main function of the rectum in the digestive system?

  • To store and temporarily hold faeces. (correct)
  • To facilitate the absorption of nutrients.
  • To completely digest food before absorption.
  • To synthesize digestive enzymes.

    • Which of the following statements about the liver is correct?

    <p>The liver converts amino acids into proteins.</p> Signup and view all the answers

    What is the process of egestion primarily responsible for?

    <p>Removing excess and unused food from the body.</p> Signup and view all the answers

    What role does amylase play in the digestive process?

    <p>It digests starch into maltose.</p> Signup and view all the answers

    What is the primary function of the oesophagus in digestion?

    <p>To transport food to the stomach using peristalsis.</p> Signup and view all the answers

    Which statement best describes the nature of chyme?

    <p>It is a mixture of food and gastric juice.</p> Signup and view all the answers

    How does the stomach contribute to the process of digestion?

    <p>It secretes gastric juices that chemically break down food.</p> Signup and view all the answers

    What is the optimal pH level for pepsin to function effectively?

    <p>Acidic pH (around 2)</p> Signup and view all the answers

    What is the primary purpose of digestion in the human body?

    <p>To break down large food particles into smaller, soluble molecules</p> Signup and view all the answers

    Which type of digestion occurs in the mouth?

    <p>Both mechanical and chemical digestion</p> Signup and view all the answers

    What role do teeth play in the digestive process?

    <p>They reduce food particles for easier swallowing</p> Signup and view all the answers

    Which digestive enzyme is responsible for breaking down starch into maltose?

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

    Which of the following statements about digestion is true?

    <p>Only soluble molecules can be absorbed into the bloodstream</p> Signup and view all the answers

    What are the products of protein digestion?

    <p>Amino acids and polypeptides</p> Signup and view all the answers

    Which of these is NOT a function of the digestive system?

    <p>Transporting oxygen throughout the body</p> Signup and view all the answers

    How does digestion contribute to energy production in the body?

    <p>By converting glucose into energy</p> Signup and view all the answers

    What is the primary function of the small intestine?

    <p>Absorption of digested food</p> Signup and view all the answers

    Which enzyme is responsible for the digestion of starch into maltose?

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

    Which accessory organ produces bile that aids in fat digestion?

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

    What does bile primarily do to fats in the digestive system?

    <p>Emulsifies fats into smaller droplets</p> Signup and view all the answers

    What condition is characterized by the loss of healthy villi in the small intestine?

    <p>Celiac disease</p> Signup and view all the answers

    What structure in the small intestine increases the surface area for absorption?

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

    Which of the following is NOT a product of digestion in the duodenum?

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

    What is the purpose of assimilation in the digestive process?

    <p>To move digested food molecules into body cells</p> Signup and view all the answers

    Study Notes

    Digestion: The Breakdown of Food

    • Digestion is the process where large, insoluble food molecules are broken down into smaller, soluble molecules that be absorbed.
    • This process is necessary because food molecules are too large or insoluble to be absorbed directly into the bloodstream and cells.
    • Digestion breaks down food into glucose (from carbohydrates), amino acids (from proteins), and fatty acids and glycerol (from lipids).
    • These smaller molecules can then be absorbed into cells to provide energy (glucose), build new cells (amino acids), and other functions (fatty acids).

    Types of Digestion

    • Mechanical Digestion: Physically breaking down food into smaller pieces. This is done by chewing (mouth) and churning (stomach).
    • Chemical Digestion: Breaking down food molecules using enzymes.

    Digestive Enzymes

    • Carbohydrases: Break down carbohydrates (e.g., amylase digests starch into maltose, maltase breaks down maltose into glucose).
    • Proteases: Break down proteins (e.g., pepsin and trypsin break down polypeptides into amino acids).
    • Lipases: Break down lipids (e.g., lipase breaks down lipids into fatty acids and glycerol).

    The Digestive System

    • Alimentary Canal: A long, coiled, muscular tube that runs from the mouth to the anus.
    • Mouth (Buccal Cavity):
      • Mechanical Digestion: Teeth cut, tear, and grind food into smaller pieces, increasing surface area for enzymes.
      • Chemical Digestion: Saliva moistens food and amylase from saliva begins breaking down starch into maltose.
      • Tongue: Rolls the partly digested food into a bolus for swallowing.
    • Oesophagus (Gullet):
      • Peristalsis: Muscular contractions push the food bolus to the stomach.
      • No digestive enzymes produced, but saliva's amylase continues digesting starch.
    • Stomach:
      • Mechanical Digestion: Muscles churn food, further breaking it down.
      • Chemical Digestion: Gastric juice (HCl and pepsin) is released:
        • Pepsin: Breaks down proteins into polypeptides.
        • HCl: Kills bacteria, provides an acidic pH for pepsin's optimal function.
      • Chyme: Mixture of food and gastric juice.
    • Small Intestine (Duodenum): MOST DIGESTION & ABSORPTION OCCURS HERE
      • Chemical Digestion: Pancreatic juice (from pancreas) contains enzymes:
        • Amylase: Continues starch digestion.
        • Maltase: Completes maltose digestion to glucose.
        • Trypsin: Digests polypeptides into amino acids.
        • Lipase: Digests lipids into fatty acids and glycerol.
    • Accessory Organs: Help with digestion but are not part of the alimentary canal:
      • Pancreas: Secretes pancreatic juice into the small intestine.
      • Liver: Produces bile, stores it in the gall bladder, and releases it into the duodenum.
        • Bile: Emulsifies fats, increasing surface area for lipase to work.
    • Small Intestine (Overall):
      • Villi: Finger-like projections on the small intestine wall, increasing surface area for absorption of nutrients.
      • Microvilli: Tiny projections on each cell of the villi - further enhancing absorption.
      • Digested food: Diffuses through the villi into the bloodstream.
    • Large Intestine:
      • Absorption: Water and mineral salts are absorbed.
      • Formation of Faeces: Undigested food, fiber, and bacteria form faeces.
    • Rectum: Temporarily stores faeces until egestion.
    • Anus: Egestion - the removal of faeces from the body.

    Assimilation

    • Movement of digested food molecules into body cells for use.
      • Glucose: Used in respiration for energy.
      • Amino acids: Used to build new proteins.
    • The Liver plays a crucial role in assimilation:
      • Converts glucose to glycogen for storage.
      • Converts amino acids into proteins.
      • Breaks down alcohol, drugs, and toxins.

    Studying That Suits You

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

    Quiz Team

    Related Documents

    Human Nutrition PDF

    Description

    Explore the fascinating process of digestion, where large food molecules are transformed into smaller, absorbable units. This quiz covers both mechanical and chemical digestion, as well as the critical role of digestive enzymes. Test your understanding of how nutrients are broken down and absorbed by the body.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser