Cell Membranes Flashcards
Integral proteins
Sites for chemical reactions(enzymes); and (pumps) for Active transport
Glycoproteins
W/ carbohydrates; make chemical receptors
Channel proteins
Carry molecules through the plasma membrane
Cholesterol
Affects fluidity at different temperatures (no polar)
Peripheral proteins
Act as receptors and recognize other cells
Hydrophilic phosphate heads
Water loving
Hydrophobic phosphate tails
water fearing
Functions of plasma membrane
- Hold cell together
- Control what goes in and out
- Protect the cell
- Allow the cell to recognize and be recognized
- Bind to other cells and molecules
- A site for biochemical reactions
The fluid mosaic model
Membrane is flexible, adaptable, and in motion; fluidity of membrane allow for quick reformation
Functions of membrane proteins
- Hormone binding sites
- Fixed enzymes
- Cell adhesion
- Channels for facilitated diffusion
- Cell signaling
- Active transport pumps
- Electron carriers in photosynthesis and cell respiration
Diffusion
- Passive
2. Small and uncharged molecules
Concentration gradient
The difference in concentration of a substance between two locations
Factors affecting rate of diffusion
- Concentration gradient
- Surface area (increase surface area=increased rate of diffusion)
- Length of diffusion path
Facilitated diffusion
- Passive
2. Used a carrier protein which is specific to the type of molecule
Osmosis
- Passive
2. Transport of water from low solute concentration to high solute concentration
Hydrolysis of a high energy bond in ATP
The bond releases one phosphate and a lot of energy
Active transport
- High to low concentration
- Use ATP
- Key in homeostasis
Exocytosis
The export of macromolecules from the cell
Endocytosis
The import of macromolecules
Phagocytosis
The ingestion of solid molecules
Pinocytosis
The ingestion of liquids and solutes
Vesicles transport
Exocytosis of protein molecules via the Golgi apparatus
