gas exchange/movement of particles - topic 2 Flashcards
(10 cards)
1
Q
describe the function of carrier proteins in a cell membrane
A
- can switch between 2 shapes
- movement occurs down a concentration gradient
- known as facilitated diffusion
- transport of polar molecules or charged particles
- active transport can also occur here
2
Q
describe the structure and function of channel proteins in a cell membrane
A
- pores that extend from one side of the membrane to the other
- allow charged substances to move trough the membrane
- gated until it recieves signal from molecule
3
Q
give the eqution for ficks law
A
rate of diffusion = (surface area x concentration difference)/thickness of membrane
4
Q
describe the structure of the alveoli
A
- single layer of squamous epithilium
- for easy diffusion of gases
- layer of moisture for gases to dissolve into
- lined with capillaries
5
Q
describe the structure of a cell membrane
A
- Bilayer meaning 2 layers of phospholipids
- phopholipid fatty acid, non-polar tail on inside
- phopholipid phosphate, polar head on outside
- contain proteis for facilitate diffusion
- cholesterol to maintain fluidity
- glycoproteins and glycolipids fr cell to cell communication
6
Q
why is the cell membrain describes as a fluid mosaic?
A
- the scattered pattern of the components of the membrane looks like a mosaic
- glycolipids and proteins can move around the layer giving the fluidity
7
Q
give two factors that effect a membranes permeability
A
- temperature
- PH
8
Q
give reasons why the permeability of a membrane increases as temperature increases
A
- enzymes dentature
- more kinetic energy causes phopholipids in the membrane to move more and so are not as tightly packed together
- volume of water expands increasing pressure on the membrane ad damaging it
9
Q
osmosis definition
A
the net movement of water particles from a low solute concentration to a high solute concentration
10
Q
A
