Cell Biology Overview

Definition: Study of cell structure, function, and processes.
Cell Types:
- Prokaryotic Cells: No nucleus, smaller, simpler (e.g., bacteria).
- Eukaryotic Cells: Nucleus present, larger, more complex (e.g., plants, animals, fungi).
Cell Structure:
- Cell Membrane: Semi-permeable barrier, regulates entry and exit.
- Nucleus: Contains genetic material (DNA).
- Cytoplasm: Gel-like substance where cellular processes occur.
- Organelles:
  - Mitochondria: Powerhouse of the cell, energy production (ATP).
  - Ribosomes: Protein synthesis.
  - Endoplasmic Reticulum (ER): Rough (with ribosomes) and Smooth (lipid synthesis).
  - Golgi Apparatus: Modifies, sorts, and packages proteins.
  - Lysosomes: Digestive enzymes for waste processing.
  - Chloroplasts: Photosynthesis in plants.
Cell Cycle:
- Phases: Interphase (G1, S, G2), Mitosis (prophase, metaphase, anaphase, telophase), Cytokinesis.
- Mitosis: Division of somatic cells for growth and repair.
- Meiosis: Division for gamete formation, involves two rounds of division.

Definition: Study of microorganisms, including bacteria, viruses, fungi, and protozoa.
Types of Microorganisms:
- Bacteria: Single-celled, prokaryotic, diverse metabolic activities; can be beneficial or pathogenic.
- Viruses: Acellular, require host cells to replicate; can cause diseases.
- Fungi: Eukaryotic, include yeast and molds; important for decomposition and medicine (e.g., penicillin).
- Protozoa: Unicellular eukaryotes, often motile; can be free-living or parasitic.
Microbial Growth:
- Requires nutrients, suitable temperature, pH, and moisture.
- Growth curve phases: Lag, log, stationary, and death phase.
Techniques in Microbiology:
- Culturing: Growing microorganisms in controlled conditions (e.g., agar plates).
- Staining: Techniques like Gram staining to differentiate bacteria.
- Microscopy: Light and electron microscopy for visualization.
Applications:
- Medicine: Antibiotics, vaccines, understanding pathogens.
- Industry: Fermentation, biotechnology.
- Environmental: Bioremediation, nutrient cycling.

Study focuses on the structure, function, and processes of cells.
Prokaryotic Cells: Lack a nucleus; smaller, simpler organisms like bacteria.
Eukaryotic Cells: Contain a nucleus; larger and more complex, including plants, animals, and fungi.

Cell Membrane: Semi-permeable; regulates the movement of substances in and out of the cell.
Nucleus: Houses genetic material (DNA), controls cellular activities.
Cytoplasm: Gel-like medium where biochemical processes occur.

Mitochondria: Known as the powerhouse of the cell; responsible for ATP energy production.
Ribosomes: Sites of protein synthesis, can be free-floating or attached to the endoplasmic reticulum.
Endoplasmic Reticulum (ER): Two types—Rough ER (with ribosomes for protein synthesis) and Smooth ER (involved in lipid synthesis).
Golgi Apparatus: Responsible for modifying, sorting, and packaging proteins for secretion or delivery to other organelles.
Lysosomes: Contain digestive enzymes that break down waste materials and cellular debris.
Chloroplasts: Present in plant cells; sites of photosynthesis, converting sunlight into energy.

Comprises phases: Interphase (subdivided into G1, S, G2), Mitosis (includes prophase, metaphase, anaphase, telophase), and Cytokinesis.
Mitosis: Process of somatic cell division crucial for growth and repair of tissues.
Meiosis: Special cell division for gamete formation; involves two rounds of division leading to genetic diversity.

Field of study concerning microorganisms, including bacteria, viruses, fungi, and protozoa.

Bacteria: Unicellular and prokaryotic; can exhibit beneficial or pathogenic behavior.
Viruses: Acellular entities that require a host cell to replicate; often responsible for various diseases.
Fungi: Eukaryotic organisms, including yeasts and molds; play significant roles in decomposition and medical applications, such as penicillin production.
Protozoa: Unicellular eukaryotes that may be motile; can exist as free-living organisms or parasites.

Requires specific conditions: nutrients, optimal temperature, appropriate pH, and moisture.
Growth phases include Lag, Log, Stationary, and Death phases.

Culturing: Controlled growth of microorganisms, often on agar plates.
Staining: Techniques like Gram staining help differentiate bacteria based on cell wall characteristics.
Microscopy: Uses light or electron microscopy to visualize microorganisms.

Medicine: Development of antibiotics and vaccines; helps understand and combat pathogens.
Industry: Utilizes microbial processes in fermentation and biotechnology.
Environmental: Involves bioremediation and nutrient cycling to sustain ecosystems.