Cell Structure, Function, and Organization

ATI TEAS Study Manual: Cell Structure, Function, and Organization

Overview of Cell Structure, Function, and Organization

  • This section focuses on the TEAS task requiring understanding of human anatomy and physiology.

  • Importance of recognizing the hierarchy of structures and functions in the human body.

  • Need for knowledge of cell components and their functions, including differentiation between mitosis and meiosis.

  • Resources available include textbooks, online content, quizzes, and free online textbooks for concept learning and memorization.

Biological Hierarchy of the Body

  • Biological Hierarchy: Organizes structures from basic to complex.

    • Chemical Level: Chemicals build cells.

    • Macromolecules: Large chemicals crucial for life; include:

    • Carbohydrates: Sugars and starches that the body breaks down into glucose.

    • Proteins: Composed of amino acids linked by peptide bonds.

    • Lipids: Fats that provide energy and support cellular structure.

    • Nucleic Acids: Long molecules made of nucleotides; includes DNA and RNA.

  • Cell as the Fundamental Unit of Life:

    • Over 250 different cell types enable various life processes.

  • Tissues: Groups of similar cells acting together; types include:

    • Epithelial Tissue: Covers surfaces and organs.

    • Connective Tissue: Supports and binds other tissues.

    • Nervous Tissue: Sends and receives signals.

    • Muscular Tissue: Responsible for movement.

  • Organs: Structures made of different tissues performing specific tasks (e.g., lungs deliver oxygen).

  • Organ Systems: Groups of organs functioning together; example: Nervous System.

    • Nerves and brain coordinate information processing and interact with other systems (e.g., Muscular System).

Objectives

  • Describe levels of hierarchical organization in the body (from cells to tissues).

  • Identify components of a cell and their functions:

    • Obtaining and using energy.

    • Cell reproduction.

    • Cell growth and metabolism.

  • Distinguish between mitosis and meiosis processes.

Definitions and Explanations

  • Mitosis: Eukaryotic cell division resulting in two daughter cells with the same chromosome number as the parent cell.

  • Meiosis: Specialized cell division producing haploid gametes in diploid organisms.

  • Macromolecules: Very large molecules essential to life; include:

    • Carbohydrates

    • Proteins

    • Lipids

    • Nucleic Acids

  • Nucleus: Large organelle housing chromosomes, regulating cell activities.

  • Cell (Plasma) Membrane: Maintains cell environment via selective permeability.

  • Cytoplasm: Material within a eukaryotic cell supporting structures and facilitating material transfer.

  • Organelle: Specialized cell part with specific functions, found in cytoplasm.

Cell Structure and Function

  • Cell: The basic unit of all living organisms.

  • Organelles: Specialized structures in the cytoplasm each performing specific functions:

    • Mitochondrion: Site of energy production.

    • Nucleus: Contains genetic material and regulates cell activity.

    • Ribosomes: Sites of protein synthesis; located on rough endoplasmic reticulum or freely in cytoplasm.

    • Endoplasmic Reticulum (ER):

    • Rough ER: Contains ribosomes; synthesizes and processes proteins.

    • Smooth ER: Lacks ribosomes; synthesizes lipids and detoxifies toxins.

    • Golgi Apparatus: Processes proteins and lipids.

    • Lysosome: Aids in digestion and recycling of materials; destroys viruses and bacteria.

    • Vacuole: Stores substances (water, toxins, carbohydrates).

Mitosis and Meiosis Processes

  • Mitosis: Cell duplication for tissue growth and repair.

    • Produces two genetically identical daughter cells.

    • Stages of mitosis:

    • Interphase: DNA replication.

    • Prophase: Chromosomes condense, become visible.

    • Metaphase: Chromosomes line up along the cell equator.

    • Anaphase: Chromosomes are pulled apart to opposite poles.

    • Telophase: Two nuclei form; cytokinesis occurs.

  • Meiosis: Produces haploid gametes through two rounds of division.

    • Each gamete contains half the genetic information of the original germ cell.

    • Stages of meiosis:

    • Interphase: DNA replication.

    • Meiosis I:

      • Prophase I: Homologous chromosomes pair, cross-over occurs.

      • Metaphase I: Homologous chromosomes align in pairs.

      • Anaphase I: One chromosome from each pair is pulled to poles.

      • Telophase I: Nuclear membranes form, cell separates into two.

    • Meiosis II:

      • Prophase II: Chromosomes condense in haploid cells.

      • Metaphase II: Chromosomes align.

      • Anaphase II: Sister chromatids separate to opposite ends.

      • Telophase II: Nuclear membranes form; results in four haploid daughter cells.

Additional Definitions

  • Gamete: Sex cell; sperm in males, egg (ova) in females.

  • Chromosome: Structure comprising DNA and protein containing genetic information.

  • Chromatid: One of two duplicates of a chromosome during the cell cycle.

Practice Problems

  1. List the six components of the biological hierarchy of the body, from least to most complex.

  2. What describes the function of the ribosome?

    • A. Protein synthesis

    • B. Energy production

    • C. Cell movement

    • D. Storage of molecules

  3. Which organelles would be abundant in muscle cells which need large energy amounts?

    • A. Ribosomes

    • B. Mitochondria

    • C. Cytoskeleton

    • D. Cell membrane

  4. Which organelle houses the genetic material?

    • A. Nucleus

    • B. Ribosomes

    • C. Cell membrane

    • D. Lysosomes

  5. Write two or three sentences defining and differentiating mitosis and meiosis.