Physiology: The Cell Chapter
10 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

What is the main function of the cell membrane in human cells?

  • To provide shape and support to the cell (correct)
  • To facilitate cell division
  • To enable transportation of nutrients and waste (correct)
  • To store genetic information
  • Which of the following cell types is known to lack a nucleus when mature?

  • Muscle cells
  • Red blood cells (correct)
  • Intestinal cells
  • Nerve cells
  • What structural feature is primarily responsible for the selective permeability of the cell membrane?

  • Cholesterol molecules
  • Integral proteins
  • Phospholipid bilayer (correct)
  • Peripheral proteins
  • Which type of protein is mostly found within the phospholipid bilayer and spans the membrane?

    <p>Integral proteins</p> Signup and view all the answers

    What role does cholesterol play in the cell membrane?

    <p>Decreases fluidity, stabilizing the membrane</p> Signup and view all the answers

    What role do membrane proteins play in the transport of small water-soluble substances across the cell membrane?

    <p>Channels that create pores</p> Signup and view all the answers

    Which of the following describes the primary function of the nucleus in human cells?

    <p>Synthesis of ribosomal RNA and storage of genetic information</p> Signup and view all the answers

    What is the function of carrier proteins found in membrane proteins?

    <p>Transport larger water-soluble substances across the membrane</p> Signup and view all the answers

    Which component is NOT typically found in the structure of the nucleus?

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

    How do enzymes associated with membrane proteins function in cellular activities?

    <p>By catalyzing reactions to terminate the effects of hormones</p> Signup and view all the answers

    Study Notes

    Cell Overview

    • Cells are the smallest living units in the human body, which is multicellular.
    • Human cells rely on each other, unlike microorganisms like bacteria that operate independently.
    • Cell sizes vary, mostly observed under a microscope, measured in micrometers (1 μm = 1/1,000,000 m).
    • The human ovum is the exception, visible to the naked eye.

    Cell Structure

    • Human cells share common features: cell membrane, nucleus, cytoplasm, and organelles.
    • Red blood cells uniquely lack a nucleus and organelles when mature.

    Cell Membrane

    • Also known as the plasma membrane, surrounds the cytoplasm and organelles.
    • Composed of phospholipids, cholesterol, and proteins, with a double-layer structure allowing selective permeability.
    • Cholesterol stabilizes the membrane by reducing its fluidity.

    Membrane Proteins

    • Two types:
      • Integral (transmembrane) proteins, often glycoproteins.
      • Peripheral proteins, mostly on the inner membrane surface.
    • Functions include:
      • Channels for small molecules (e.g., sodium, potassium).
      • Carriers for larger water-soluble substances.
      • Antigens for identifying the body’s cells.
      • Receptors for hormones initiating physiological responses.
      • Enzymes that can terminate hormone effects.

    Nucleus

    • Found in all human cells except mature red blood cells.
    • Enclosed by a double-layer nuclear membrane with pores and contains nucleoli and chromosomes (46 total).
    • The nucleolus produces ribosomal RNA, essential for protein synthesis.
    • The nucleus controls cellular functions by housing genetic material (DNA).

    Cytoplasm and Organelles

    • Cytoplasm consists of minerals, gases, organic molecules, and organelles.
    • Cytosol is the water portion of cytoplasm without organelles.
    • Organelles perform specific functions:
      • Endoplasmic Reticulum (ER):
        • Rough ER has ribosomes for protein synthesis.
        • Smooth ER synthesizes lipids.
      • Ribosomes: Site for protein synthesis made of protein and ribosomal RNA.
      • Proteasomes: Degrade unneeded or damaged proteins.

    Additional Organelles

    • Golgi Complex: Modifies, sorts, and packages proteins and lipids for transport.
    • Mitochondria:
      • Double-membraned, site of ATP production through aerobic respiration.
      • Contains maternal mitochondrial DNA and duplicates during cell division.
    • Lysosomes: Contain digestive enzymes for degrading bacteria engulfed by white blood cells.
    • Centrioles: Organize spindle fibers during cell division, located perpendicular to each other.

    Cellular Projections

    • Cilia: Short, numerous projections that move materials across the cell surface (e.g., in fallopian tubes).
    • Flagella: Long, singular projection aiding in movement, exemplified by sperm cells.

    Studying That Suits You

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

    Quiz Team

    Description

    Explore the fundamental building blocks of life in this quiz on cell physiology. Understand the differences between human cells and microorganisms, along with their sizes, shapes, and functions. Test your knowledge on how cells work together to support the human body.

    More Like This

    Use Quizgecko on...
    Browser
    Browser