Plasma membrane Flashcards
(22 cards)
Define semi-permeable
Allowing certain substances to pass through, but not others. Especially allowing the passage of a solvent but not certain solutes.
Define hydrophobic
Molecule that repels water
Define hydrophilic
Molecule that is attracted to water
Describe the phosphate head
The phosphate head is hydrophilic, which also carries a negative charge.
Describe the lipid tails
The lipid tails are hydrophobic, uncharged, and are 2 fatty acid tails (saturated and unsaturated)
Define active transport
Active transport is where there is energy required for exchange of materials.
Difference between going against the concentration gradient and following the concentration gradient
When following the concentration gradient it means materials are going from a high to low concentration, whereas if going against the concentration gradient it means materials are going from a low to high concentration gradient.
Define passive transport
Passive transport is where there is no energy required for exchange of materials.
Transport across the membrane is determined by:
Size, charge, and polarity
Types of passive transport include:
Simple diffusion, facilitated diffusion, and osmosis
Types of active transport include:
Bulk transport, Endocytosis (phagocytosis, and pinocytosis), Exocytosis
What is simple diffusion?
Simple diffusion is when only small polar or non-polar materials just pass straight through the membrane.
What is facilitated diffusion?
Facilitated diffusion is when only small or large polar molecules through protein transporters (channel and carrier protein).
What is osmosis?
Movement of water down an osmotic gradient, net movement of water molecules.
Channel protein
