2A Membrane Structure Flashcards
What has a similar molecular structure to phospholipids?
Triglycerides
What are the components of the Fluid Mosaic Model?
Phospholipid Bilayer, Integral and Peripheral Proteins, Glycoproteins and Glycolipid Chains, Cholesterol
Describe the structure of a phospholipid molecule?
Consist of one glycerol molecule linked to two fatty acids in a phosphate group.
Describe the structure of the phospholipid bilayer?
Made up of two layers of phospholipids with the hydrophobic tails facing each other on the inside, with the hydrophilic head groups outside.
Amphiphilic (amphipathic)
A molecule with a hydrophilic group attached to a hydrophobic one.
Selectively permeable
Allows certain substances to freely cross the membrane while inhibiting others.
What molecule can cross the membrane without the use of a channel?
Small, non-charged molecules
Types of transport across the cellular membrane.
Active transport is against a gradient using ATP. Bulk transport is large particles with a transport vesicle. Diffusion moves towards lower concentration, no energy. Facilitated transport moves towards lower concentration, no energy but channel needed.
Concentration gradient
When a solute is more concentrated in one area than another.
Osmosis
Diffusion of water across a selectively permeable membrane.
Isotonic solution
When a solute and the water concentration are equal on both sides.
Hypotonic solution
When the concentration of the solute is higher in the cell than the solution.
Hypertonic solution
Have a higher concentration of solute in solution compared to cell.
Facilitated diffusion
The molecule combine with a carrier protein, follow concentration gradient, no energy required.
Active diffusion
The molecule combines with a carrier protein, move against gradient, energy required.
Exocytosis
The movement out of the cell.
Endocytosis
Movement into the cell.
Pinocytosis
Movement of many small solid particle or liquid.
Phagocytosis
Movement of large, solid molecules.
Plasmodesmata
Found in plant cells, they penetrate the cell walls for passage of material between cells.
Channel protein
Allows a charged molecule to cross the membrane by diffusion.
Carrier protein
Carries a specific charged molecule across the membrane by active transport.
Marker protein
Carbohydrate chain attached to cell surface that identifies cell
Receptor protein
Interacts with specific molecules and functions for cell signaling.
Enzymatic protein
Site of chemical reaction.
Junction protein
Joins cells together and can be loose tight or in-between.
Aquaporin
Moves water across the membrane.
