Cell Anatomy and Physiology

Page 1: Overview

• Subject: Cell Anatomy and Physiology

Page 2: Learning Objectives

• Understand the organization of eukaryotic cells

• Identify organelles and their functions

• Learn stages of mitosis

• Understand diffusion and osmosis processes

Page 3: Key Concepts

• Cell Anatomy: Principle structures of the cell

• Cell Physiology: Cell division and membrane processes

Page 4: Evolution of Cells

• Prokaryotes:

  • Unicellular, no true nucleus, scattered nuclear material, no organelles

• Eukaryotes:

  • True nucleus, organized nuclear material, contains organelles

Page 5: Cell Structures

• Prokaryotic Cell Components: Cytoplasm, Nucleoid, Cell wall, Pilli, Plasma membrane, Cytoskeleton

• Eukaryotic Cell Components: Nucleus, Nucleolus, Endoplasmic reticulum, Golgi apparatus, Vesicle

Page 6: Principal Structures of the Animal Cell

1. Plasma Membrane: Protects internal structures

2. Cytosol: Intercellular fluid with proteins, enzymes, ions

3. Organelles: Structures with specific functions

4. Inclusions: Temporary structures for secretion/storage

Page 7: Plasma Membrane Composition

• Types of Lipids:

  • Phospholipids (75%)

  • Glycolipids (5%)

  • Cholesterol (20%)

• Amphipathic Nature: Hydrophilic and hydrophobic ends

Page 8: Additional Cell Wall Characteristics

• Cilia: Move fluid across cell surface

• Flagellum: Moves the cell through fluid

Page 10: Membrane Permeability

• Lipid-soluble Molecules: Pass easily

• Water-soluble Molecules: Do not pass easily

Page 11: Cytosol, Cytoskeleton, Cytoplasm

• Cytosol: Gel-like fluid with various substances

• Cytoskeleton: Protein filaments providing support

• Cytoplasm: Cytosol + organelles (excluding nucleus)

Page 12: Cytoskeleton Components

1. Microfilaments: Support and shape

2. Microtubules: Conveyor belt for organelles, cell division

3. Intermediate Fibers: Structural reinforcement

Page 14: Organelles Overview

• Organelles function as 'organs' of the cell

• Key organelles include:

  1. Mitochondria

  2. Ribosome

  3. Endoplasmic reticulum

  4. Golgi apparatus

  5. Lysosome

  6. Peroxisome

  7. Centrosome

  8. Nucleus

Page 15: Mitochondria

• Main site for ATP synthesis

• Contains cristae for ATP production

• Capable of self-replication

Page 16: Ribosomes

• Smallest organelle, site of protein synthesis

• Composed mainly of rRNA

• Translates mRNA for protein production

Page 17: Endoplasmic Reticulum (ER)

• Site of chemical reactions

• Two types: Rough ER (RER) and Smooth ER (SER)

Page 18: Rough Endoplasmic Reticulum

• Ribosomes attached, synthesizes proteins for secretion

• Proteins transported via vesicles

Page 20: Smooth Endoplasmic Reticulum

• No ribosomes, synthesizes lipids

• Detoxifies chemicals in the liver

Page 22: Golgi Apparatus

• Processes and repackages proteins from ER

• Forms lysosomes from enzymatic proteins

Page 23: Lysosomes

• Digestive enzymes for various molecules

• Triggers autolysis when a cell dies

Page 24: Peroxisomes

• Contain oxidizing enzymes for detoxification

• Convert hydrogen peroxide into water and oxygen

Page 26: Centrosome and Centrioles

• Site of microtubule formation for cell division

• Base for cilia and flagella

Page 27: Nucleus

• Control center containing DNA

• Components: Nuclear envelope, nucleoplasm, chromatin, nucleolus

Page 28: Nucleolus

• Site of ribosome synthesis

• Contains rRNA

Page 30: Cell Division

• Mitosis: Division of a parent cell into two identical daughter cells

• Meiosis: Formation of sperm and egg cells (not covered in detail)

Page 31: Stages of Mitosis

1. Interphase (G1, S, G2, G0)

2. Mitotic Phase (Prophase, Metaphase, Anaphase, Telophase)

3. Cytokinesis

Page 37: Cell Membrane Processes

• Passive Processes: No ATP required (Diffusion, Osmosis)

• Active Processes: ATP required (Active transport, Endocytosis, Exocytosis)

Page 39: Diffusion

• Movement from higher to lower solute concentration

• Achieves equilibrium

Page 42: Osmosis

• Diffusion of water from lower to higher solute concentration

• Occurs across a semi-permeable membrane

Page 46: Concentration Gradients

• Isotonic: Equal solute concentration

• Hypertonic: Higher solute concentration outside

• Hypotonic: Higher solute concentration inside

Page 49: Active Transport

• Requires ATP, does not need a concentration gradient

• Example: Na+/K+ pumps

Page 50: Endocytosis and Exocytosis

• Requires ATP for large macromolecules

• Types of endocytosis: Phagocytosis, Pinocytosis, Receptor-mediated endocytosis

Page 51: Summary of Processes

• Passive Process: Requires concentration gradient, no ATP

• Active Process: No concentration gradient required, uses ATP