factors affecting membrane structure and permeability Flashcards
what does increasing temperature do to the membrane fluidity and components
increases kinetic energy in phospholipids and increases membrane fluidity as they will move more
affect positioning of membrane embedded proteins altering the ability to catalyse
also increases diffusion due to molecules having more kinetic energy
what is the difference between saturated and unsaturated fatty acids
saturated- no double bonds
unsaturated- double bonds has kinks in its chain
what does decreasing temperature do to the membrane
Makes it rigid as it compresses the saturated fatty acid tails and causing them to pack closely together
How does cholesterol act as a buffer to low temperatures
how do unsaturated fatty acid tails maintain fluidity at low temperatures
Because when they become compressed (like the saturated) the kinks in their tails push phospholipids apart, maintaining fluidity
how does cholestrol maintain fluidity at low temperatures
it inserts/ embeds itself between the phospholipids preventing them packing to closely
what temperature will denature proteins
40+ degrees will denature the integral proteins
- Carrier
-Channel
Are changes in fluidity reversible
Yes
E.g. high temperatures increase in fluidity and permeability can be reversed by decreasing the temperature
what structure of the integral proteins needs to be impacted in order for the protein to be denatured
Tertiary structure
what practical is used to experiment membrane permeability
Beetroot pigment experiment
In the beetroot required practical, a colorimeter is used. How does a colorimeter determine permeability
The colorimeter emits a wavelength of light to the detector on the other side. The detector records the amount of light absorbed by the sample..
The lower the absorbance
