There are two main types of cells: prokaryotic cells which lack nuclei and eukaryotic cells which contain nuclei. Eukaryotic cells include plant and animal cells. All cells are surrounded by a plasma membrane made of phospholipids, carbohydrates, proteins and cholesterol that contains organelles like the nucleus, mitochondria and chloroplasts. Transport across the cell membrane can occur through passive diffusion, osmosis and facilitated diffusion which don't require energy or through active transport which uses ATP-powered transport proteins to move molecules against their concentration gradient.

1. Review of Cells

2. Types of Cells Prokaryotic: Do not have a nucleus Bacteria, protists and simple single celled organisms. Eukaryotic: Have a true nucleus Include plant and animal cells

3. Plasma membrane Made up of: Phospholipids (bilayer) Carbohydrates (receptor molecules) Proteins (transport channels) Cholesterol (structure and stability)

4. Cell Organelles Cell membrane Cell wall (plants only) Endoplasmic reticulum Smooth and Rough Golgi apparatus Mitochondria Chloroplasts (plants only)

5. Cell Organelles Lysosomes Vacuole Centrioles (visible in animals) Nucleus Nucleolus Ribosomes

6. Transport How do things molecules or particles move? Gases and Liquids can have particles suspended in them Random Collisions of these particles create movement, and cause them to spread out.

7. Passive Transport Does not require energy Two types: Diffusion: from high concentration to low concentration. Until an equilibrium is reached. Osmosis: the diffusion of water. Facilitated Diffusion: The diffusion of larger molecules, with the help of transport protein. Facilitated Diffusion

8. Active Transport Transport across the membrane that requires the use of energy. Usually occurs up the concentration gradient Uses ATP