Basic Genetic & Molecular Biology Notes

Learning Outcomes

  • Define terms related to cells
  • Describe Eukaryote and Prokaryote
  • Identify cell structure and functions of organelles
  • Define virus

Introduction to Cells

  • Cell Theory: All living organisms consist of cells, cells arise from pre-existing cells, they contain genetic material, and metabolic reactions occur within cells.

Cellular Overview

  • Cell: Basic building blocks of organisms.
    • Unicellular: single cell (e.g., bacteria)
    • Multicellular: multiple cells (e.g., humans and plants)

General Characteristics of Cells

  • Bounded by plasma membrane, filled with cytoplasm, contain DNA, and ribosomes.
  • Types: Prokaryotic (simple, no nucleus) and Eukaryotic (complex, has nucleus).

Prokaryotic Cells

  • Simpler structure found in bacteria and Archaea.
  • Lack a true nucleus; DNA in nucleoid region.
  • Cartoon structures include the cell wall, ribosomes, and flagella.

Eukaryotic Cells

  • Larger; include protozoa, fungi, plants, and animals.
  • Have a true nucleus and membrane-bound organelles (e.g., mitochondria, Golgi apparatus).

Cell Structures and Functions

  • Plasma Membrane: Selectively permeable, regulates material movement, involved in signaling.
  • Organelles:
    • Nucleus: Contains DNA; control center for cell activity.
    • Ribosomes: Sites of protein synthesis.
    • Endoplasmic Reticulum: Smooth and rough types for protein and lipid production.
    • Golgi Apparatus: Modifies and ships proteins.
    • Lysosomes: Digest macromolecules.
    • Vacuoles: Storage and waste disposal.
    • Mitochondria: Energy generation through ATP.
    • Chloroplasts: Site of photosynthesis in plant cells.
    • Peroxisomes: Metabolic compartments for oxidative reactions.
    • Cytoskeleton: Provides structural support and organization.

Microorganisms

Bacteria

  • Prokaryotes studied in bacteriology; reproduce asexually via binary fission.
  • Shapes vary (spherical, rod, spiral).

Fungi

  • Eukaryotic decomposers, reproduce asexually. Include yeasts and molds, some beneficial for humans.

Protozoa

  • Unicellular eukaryotes that move independently. Reproduce sexually or asexually.

Algae

  • Photosynthetic organisms, may be unicellular or multicellular.

Viruses

  • Acellular entities, not considered living. Require a host to replicate and can cause diseases in humans.