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Anatomy & Physiology: Cell Structure and Function

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Terms in this set (30)

  • Three major parts of a cell

    Plasma membrane: outer boundary controlling movement in/out.
    Cytoplasm: contains cytosol and organelles.
    Nucleus: control center containing DNA.

  • Phospholipid bilayer structure

    Polar heads face watery environments; nonpolar tails face inward away from water, forming a bilayer.

  • Key components of the plasma membrane

    Phospholipids, integral proteins, peripheral proteins, cholesterol, glycoproteins, glycolipids, and glycocalyx.

  • Selective permeability of plasma membrane

    The membrane acts as a barrier and receptor site, allowing only certain substances to enter or leave the cell.

  • Simple diffusion characteristics

    Molecules move from high to low concentration without protein or ATP.

  • Osmosis definition

    Diffusion of water across a membrane, sometimes via aquaporins, from high to low water concentration.

  • Facilitated diffusion

    Movement of substances high to low concentration through integral membrane proteins without ATP.

  • Active transport

    Movement of substances against their concentration gradient using proteins and ATP energy.

  • Endocytosis types

    Phagocytosis: cell eating large particles.
    Pinocytosis: cell drinking extracellular fluid.
    Receptor-mediated endocytosis: specific molecules enter via receptors.

  • Exocytosis process

    Secretory vesicle fuses with plasma membrane to release contents outside the cell.

  • Cytoplasm components

    Consists of cytosol (fluid), organelles, and inclusions inside the plasma membrane.

  • Ribosome function and locations

    Protein synthesis; free ribosomes function in cytosol, attached ribosomes on rough ER produce proteins for export or membrane.

  • Differences between rough and smooth ER

    Rough ER has ribosomes and synthesizes proteins; smooth ER lacks ribosomes and synthesizes cholesterol and detoxifies.

  • Golgi apparatus function

    Packages and ships proteins; proteins move from rough ER to cis Golgi, processed, then shipped from trans Golgi.

  • Pathway of a secreted protein

    Ribosome → Rough ER → transport vesicle → cis Golgi → trans Golgi → secretory vesicle → plasma membrane → exocytosis.

  • Lysosome role

    Membrane-bound sacs with digestive enzymes that break down bacteria, viruses, and worn-out organelles.

  • Mitochondria function and features

    Produce ATP as the cell's power plant; have outer/inner membranes, cristae, matrix, mitochondrial DNA, and ribosomes.

  • Peroxisomes function

    Contain oxidase and catalase enzymes; detoxify harmful substances by converting hydrogen peroxide to water and oxygen.

  • Cytoskeleton components

    Microfilaments (actin), intermediate filaments (tough fibers), and microtubules (tubulin tubes) provide structure and aid division.

  • Centrosome and centrioles function

    Centrosome contains centrioles that organize microtubules for cilia, flagella, and mitotic spindle formation.

  • Nucleus structure and function

    Control center with nuclear envelope, pores, lamina, chromatin, and nucleolus; directs protein synthesis and stores DNA.

  • DNA organization hierarchy

    DNA double helix → wrapped around histones → nucleosomes → chromatin → chromatid → chromosome.

  • Difference between chromatin and chromosome

    Chromatin is extended DNA/protein material; chromosome is condensed chromatin during cell division.

  • Cell cycle phases

    Interphase (G₁ growth, S synthesis, G₂ growth) followed by mitotic phase (mitosis and cytokinesis).

  • Mitosis stages in order

    Prophase → Metaphase → Anaphase → Telophase → Cytokinesis (PMAT).

  • Key events in prophase

    Chromatin condenses, sister chromatids join at centromere, centrosomes move apart, spindle forms, nuclear envelope breaks down.

  • Metaphase characteristics

    Chromosomes line up at the metaphase plate in the cell center.

  • Anaphase characteristics

    Centromeres split, sister chromatids separate and move to opposite poles via shortening microtubules.

  • Telophase characteristics

    Chromosomes uncoil, nuclear envelopes reform, nucleoli reappear, spindle disappears, two nuclei form.

  • Cytokinesis process

    Division of cytoplasm by contractile ring of actin microfilaments forming cleavage furrow, producing two daughter cells.