Unit 1 pt 2: Cell Basics & Membrane

Cell Theory

All living things are made of cells, cells are the basic unit of life, and all cells come from pre-existing cells.

Cell Structure

Determines the function of the cell and contributes to overall activity.

Irregular-shaped Cells

Example: nerve cells; shaped for communication

Biconcave Disc

Example: red blood cells; shape increases surface area for gas exchange.

Cube-Shaped Cell

Example: kidney tubule cells; suited for absorption and secretion.

Column-Shaped Cell

Example: intestinal lining cells; specialized for absorption.

Spherical Cell

cartilage cells; round shape for cushioning.

Cylindrical Cell

Example: skeletal muscle cells; elongated for contraction.

Phospholipid Bilayer

Double layer of lipids; forms the basic structure.

Cholesterol

Stabilizes membrane fluidity and structure.

Glycolipids

Lipids with carbohydrate chains; cell recognition.

Integral Proteins

Embedded in the membrane; transport & signaling.

Peripheral Proteins

On membrane surface; support & signaling.

Transport Proteins

Move substances across the membrane.

Cell Surface Receptors

Bind signals and start responses.

Binds molecules called Ligands

Identity Markers

Allow cells to recognize each other.

Enzymes

Catalyze chemical reactions at the membrane.

Anchoring Sites

Attach cytoskeleton for stability.

Cell-Adhesion Proteins

Help cells stick together in tissues.