[Not in Spec] Topic 2A - Gas Exchange, Cell Membranes and Transport Flashcards
What does cholesterol do to the membrane
Makes it more rigid
Name the 6 molecules found in the fluid mosaic model
- channel protein
- protein
- phospholipid
- glycolipid
- glycoprotein
- cholesterol
why is the bilayer ‘fluid’
because the phospholipids are constantly moving
State the permeability of the membrane
partially permeable
what molecules can move through gaps between the phospholipids
small molecules
what molecules can only pass through special membrane proteins
large molecules and ions
name the special membrane proteins
channel proteins and carrier proteins
what is osmosis
osmosis is the diffusion of free water molecules across a partially permeable membrane from an area of higher concentration of water molecules to an area of lower concentration
true/false:the cell membrane is mainly composed of glycolipids
false
true/false:the molecules that make up the cell membrane are constantly moving
true
true/false:molecules can only pass through the cell membrane via channel proteins
false
is facilitated diffusion passive?
yes it doesnt use energy
what do carrier proteins help transport
large molecules
what do channel proteins help transport
charged particles
describe how carrier proteins facilitate diffusion of large molecules
- large molecule attaches to a carrier protein in the membrane
- the protein changes shape
- this releases the molecule on the other side of the membrane
does facilitated diffusion move particles up or down a concentration gradient
down
which membrane protein is used in active transport
carrier protein
is active transport up or down a concentration gradient
up
whats endocytosis
when cells take in substances
whats exocytosis
when cells secrete substances
EQ. Describe the role of the CFTR protein in ensuring that the mucus produced in the lungs has the right consistency. (4 marks)
- chloride ions leave the cell through the CFTR protein and go into the mucus
- sodium ions follows the chloride ions out of the cell
- this draws water out of the cell into the mucus by osmosis
- because there is a greater concentration of solute in the mucus
What are the 3 properties of water that make it a good transport medium?
- water is polar so polar substances, like ionic and hydrophilic substances can easily dissolve in water.
- the specific heat capacity of water is very high to maintain homeostasis
- water has a high boiling point due to the hydrogen bonds
How are glycoproteins made in animal cells released
exocytosis