Honors Anatomy and Physiology: Cells

Cell Biology: Honors Anatomy and Physiology Notes

Fluid mosaic model: Describes the plasma membrane as a dynamic, flexible structure composed of a mosaic of components including lipids, proteins, and carbohydrates.
Lipid bilayer of phospholipids: The fundamental structure of the membrane.
- Hydrophilic heads: Water-loving, polar phosphate heads that face the aqueous environments inside and outside the cell.
- Hydrophobic tails: Water-fearing, nonpolar fatty acid tails that form the interior of the membrane, away from water.
Cholesterol: Embedded within the lipid bilayer, it helps regulate membrane fluidity and stability.
Proteins: Integrated within or associated with the lipid bilayer, performing various functions like transport, reception, and adhesion.
Carbohydrate chains: Extend from the cell surface, involved in cell recognition and adhesion.
Glycolipids: Carbohydrate chains attached to lipids.
Glycoproteins: Carbohydrate chains attached to proteins.

Tight junction: Creates a nearly impermeable barrier between cells, preventing substances from passing through the intercellular space. Forms a seal.
Desmosome: Provides strong adhesion and mechanical stability between cells, anchoring them together like rivets.
Gap Junctions: Channels that allow small molecules and ions to pass directly between adjacent cells, facilitating intercellular communication.

CAMs: Proteins that guide cells on the move, playing crucial roles in embryonic development, wound healing, and immune responses.
Selectin: A type of CAM that coats the cell surface and provides traction, often involved in rolling adhesion of white blood cells to blood vessel walls.
Integrin: A type of CAM that contacts an adhesion receptor, linking the cell's cytoskeleton to extracellular matrix or other cells.
Abnormal CAMs affect health:
- Lack of CAMs: Can lead to the spread of cancer, as cancer cells detach more easily and metastasize.
- Too much CAMs: Can cause inflammation of joints and conditions like arthritis, due to excessive cell adhesion and immune response.

Cytosol: The jelly-like substance filling the cell, where organelles are suspended.
Cytoskeleton: A network of protein filaments and tubules in the cytoplasm, providing structural support and facilitating cell movement.
- Microfilaments and microtubules: Key components of the cytoskeleton.
Ribosomes: Sites of protein synthesis, composed of ribosomal RNA and protein.
Endoplasmic reticulum (ER): A network of membranes involved in protein and lipid synthesis and modification.
Golgi apparatus: Modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.
Mitochondria: The