Cell membrane
Fluid mosaic model
Phospholipids make a bilayer, molecules can move laterally (fluid)
proteins interspersed (mosaic)
Phospholipid
glycerol w/ phosphate group + 3 fatty acids
Head: polar, hydrophilic
Tail: non-polar, hydrophobic
Proteins
- Carbohydrate --> glygoproteins
- Channel proteins: channels for diffusion
- Carrier proteins: active transport
- Antigens: glycoproteins for cell recognition
- Receptors: glycoproteins to receive hormonesand trigger activity
- Enzymes: speed up reactions
4 ways of movement
- Diffusion
- Osmosis
- Active transport
- Phagocytosis
Diffusion
Active transport
Phagocytosis
- pit/pseudopodium formed at cell membrane to engulf particle
- Particle enclosed in small vacuole
- cell releases enzymes to digest particle
- digested products diffuse to cytoplasm