Cell Structure and Function Quiz
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Questions and Answers

What is the primary role of centrioles during cell division?

  • To give rise to spindle fibers for chromosome attachment (correct)
  • To absorb light energy for photosynthesis
  • To store proteins and nutrients
  • To maintain the structural integrity of the cell

    • What do microfilaments primarily help with in a cell?

  • Causing changes in cell shape, such as contraction (correct)
  • Storing genetic material
  • Forming the cell wall structure
  • Generating energy through respiration

    • Which component is responsible for photosynthesis in plant cells?

  • Chloroplasts (correct)
  • Chromoplasts
  • Leucoplasts
  • Vacuoles

    • What is the primary composition of the cell wall found in plants?

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

    What is a function of vacuoles in plant cells?

    <p>Storing sugars, water, minerals, and proteins</p> Signup and view all the answers

    What effect does the insertion of cholesterol have on membrane fluidity at high temperatures?

    <p>Fluidity increases due to increased space between molecules</p> Signup and view all the answers

    What is the role of surface proteins in a cell membrane?

    <p>To initiate cell-cell communication and interaction</p> Signup and view all the answers

    How do transmembrane proteins contribute to membrane function?

    <p>They regulate the movement of substances across the membrane</p> Signup and view all the answers

    What distinguishes receptor proteins in the cell membrane?

    <p>They have specific receptor sites for particular molecules</p> Signup and view all the answers

    What is the function of recognition protein molecules?

    <p>To identify cells as belonging to the organism</p> Signup and view all the answers

    How does cholesterol generally affect fluidity in the membrane?

    <p>Decreases fluidity by reducing energy and motion of tails</p> Signup and view all the answers

    What is the primary purpose of adhesion proteins?

    <p>To link cells together and maintain tissue structure</p> Signup and view all the answers

    What determines the type of receptor proteins present in a cell?

    <p>Genetic information</p> Signup and view all the answers

    Which scientist contributed to the understanding that cells have an individual life of their own?

    <p>Theodor Schwann</p> Signup and view all the answers

    What is one distinguishing feature of prokaryotic cells?

    <p>Package DNA in a nucleoid region</p> Signup and view all the answers

    What is the ideal surface area to volume ratio for a healthy cell?

    <p>3:1</p> Signup and view all the answers

    What is primarily the function of catabolic reactions?

    <p>Breaking down large molecules into smaller ones</p> Signup and view all the answers

    Why does a larger surface area benefit a cell?

    <p>Provides more space for molecule diffusion</p> Signup and view all the answers

    Which structure acts as the control center of the cell?

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

    According to the cell theory, what did Rudolf Virchaw add?

    <p>Cells arise from pre-existing cells.</p> Signup and view all the answers

    What is the primary role of the mitochondria?

    <p>Energy production through cellular respiration</p> Signup and view all the answers

    What happens to the efficiency of nutrient uptake as a cell grows larger?

    <p>It decreases.</p> Signup and view all the answers

    What does ATP stand for and what is its role?

    <p>Adenosine Triphosphate, the main energy storage molecule</p> Signup and view all the answers

    What is a characteristic of eukaryotic cells?

    <p>Contains DNA in a nucleus</p> Signup and view all the answers

    What separates the nucleus from the cytoplasm?

    <p>Nuclear envelope</p> Signup and view all the answers

    What does an increased surface area to volume ratio minimize?

    <p>Traffic congestion of molecules</p> Signup and view all the answers

    Which component of the mitochondria is involved in the production of ATP?

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

    How is the nuclear envelope structured?

    <p>Double lipid layer with pores allowing selective transport</p> Signup and view all the answers

    What is the role of the cytoplasm?

    <p>Holds cytosol and organelles, carrying out chemical reactions</p> Signup and view all the answers

    Why do cells generally remain small in size?

    <p>To maintain a high surface area to volume ratio.</p> Signup and view all the answers

    Which type of amino acids must be acquired through diet?

    <p>Essential amino acids</p> Signup and view all the answers

    What characterizes an enzyme's active site?

    <p>It has a specific shape and chemical behavior designed for specific substrates.</p> Signup and view all the answers

    What defines a holoenzyme?

    <p>The active form of an enzyme when combined with its coenzyme or cofactor.</p> Signup and view all the answers

    What is the primary role of enzymes in biological reactions?

    <p>To increase the speed of reactions by lowering energy requirements.</p> Signup and view all the answers

    Why do some cells develop features like root hairs?

    <p>To enhance surface area for absorption of nutrients.</p> Signup and view all the answers

    What types of molecules play a role as cofactors for enzymes?

    <p>Both cations and organic molecules like vitamins.</p> Signup and view all the answers

    What happens to the cytoplasm when a vacuole in algal cells becomes very large?

    <p>It reduces the distance substances must diffuse to leave or enter the cell.</p> Signup and view all the answers

    What is the primary function of the plasma membrane?

    <p>To control the exchange of materials and messages in and out of the cell</p> Signup and view all the answers

    Which component of the plasma membrane is responsible for its flexibility?

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

    How does the structure of the phospholipid contribute to the formation of the plasma membrane?

    <p>The heads are hydrophilic and the tails are hydrophobic, forming a bilayer</p> Signup and view all the answers

    What effect does low temperature have on the fluidity of the plasma membrane?

    <p>Reduces fluidity by causing phospholipids to cluster together</p> Signup and view all the answers

    What type of substances are allowed to pass through the hydrophobic tails of phospholipids?

    <p>Fat-soluble substances</p> Signup and view all the answers

    What role do specialized protein molecules play in the plasma membrane?

    <p>To facilitate the movement of substances across the membrane</p> Signup and view all the answers

    In what way does a cell wall differ from a plasma membrane?

    <p>Cell wall adds support and is permeable, while plasma membrane is selectively permeable</p> Signup and view all the answers

    What characteristic of the plasma membrane allows it to be described as a 'liquid crystal'?

    <p>It permits rapid sideways movement of its components</p> Signup and view all the answers

    Study Notes

    Cell Structure and Function

    • Cell Theory: Cells are the basic unit of life, all living things are made of cells, cells come from pre-existing cells.
    • Prokaryotic vs. Eukaryotic Cells: Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells have a nucleus and membrane-bound organelles. Prokaryotes include bacteria and archaea, while eukaryotes include all other kingdoms.
    • Prokaryotic Cell Structure: These cells lack membrane enclosed organelles and internal compartments. DNA is organized in a region called the nucleoid. Ribosomes are present for protein synthesis. Some may also have a cell wall and extra DNA called plasmids.
    • Eukaryotic Cell Structure: Eukaryotic cells have membrane-bound organelles which are suspended in a fluid called the cytosol. DNA is contained within a membrane bound nucleus. Many such organelles perform specialized functions.
    • Surface Area to Volume Ratio: A larger surface area to volume ratio is better for cells to exchange materials efficiently with their environment. Small cells are more efficient.
    • Membrane Bound Organelles: Membranes divide the cell into different compartments, which separates the cell's function.
    • Plasma Membrane: A selectively permeable barrier separating the cell's interior from its surroundings.
    • Cytoplasm (Cytosol): This is where many chemical reactions take place in a cell. It is a gel-like fluid that holds organelles and provides the environment for cell processes.
    • Nucleus: The control center of the cell; encloses DNA organized as chromosomes.
    • Nucleolus: A part inside the nucleus where ribosomes are made.
    • Mitochondria: Site of aerobic cellular respiration, producing energy in the form of ATP.
    • Ribosomes: Build proteins from amino acids.
    • Endoplasmic Reticulum (ER): Rough ER has ribosomes for protein synthesis and modification; smooth ER synthesizes lipids and detoxifies substances.
    • Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for transport to other parts of the cell.
    • Lysosomes: Break down waste materials, cellular debris, and foreign invaders in a cell.
    • Cytoskeleton: A network of protein filaments providing support and structure to the cell. Includes microtubules, microfilaments.
    • Vacuoles: Storage sacs for water, nutrients, or waste products; larger in plant cells.
    • Plastids: Plant-specific organelle including chloroplasts (photosynthesis).
    • Cell Walls: Support and protection layer present in plant and some other cells.

    Passive Transport

    • Diffusion: The net movement of particles from high to low concentration, until equilibrium.
    • Facilitated Diffusion: Passive transport aided by proteins to allow larger or charged molecules to cross a cell membrane. This involves carrier proteins or channels.
    • Osmosis: Diffusion of water across a membrane, from high to low water concentration.
    • Isotonic: External and internal solute concentration is the same.
    • Hypotonic: External solute concentration is lower than internal.
    • Hypertonic: External solute concentration is higher than internal.

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    Description

    Test your knowledge on cell structure and function, including the distinctions between prokaryotic and eukaryotic cells. Explore key concepts such as cell theory, major organelles, and the importance of surface area to volume ratio. Perfect for biology students looking to deepen their understanding of cellular biology.

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