Flashcards
Factors Affecting Permeability/Structure
Cards in this deck (8)
- 1What are the factors that affect permeability/structure?Temperature
Solvents - 2What happens to the cell membrane as the temperature increases?Increasing temperature increases kinetic energy, meaning that phospholipids vibrate more. This makes the bilayer more unstable, making the membrane more 'leaky', allowing more molecules through that would not normally be able to
BUT! Once a certain temperature has been reached, the membrane breaks - 3What happens to the cell membrane at temperatures below 0°C?The phospholipids don't have much energy, so they can't move very much.
They are packed closely together and the membrane is rigid.
BUT! Channel/carrier proteins in the membrane denature, increasing the permeability.
Ice crystals may form and pierce the membrane, making it highly permeable when it thaws - 4What happens to the cell membrane at temperatures between 0°C and 45°C?The phospholipids can move around and are not packed as tightly together - the membrane is partially permeable.
As the temperature increases, the phospholipids move more because they have more kinetic energy - 5What happens to the cell membrane at temperatures above 45°C?The phospholipid bilayer starts to melt and the membrane becomes more permeable.
Water inside the cell expands, putting pressure on the membrane.
Channel/carrier proteins in the membrane denature so they cannot control what enters or leaves the cell - this increases permeability - 6How does the presence of organic solvents affect cell membrane permeability?Organic solvents damage cell membranes as they dissolve lipids
- 7Name two examples of organic solvents which damage cell membranesAcetone
Ethanol - 8How does increasing the concentration of organic solvents affect cell membrane permeability?Increasing the concentration of the solvent will also increase membrane permeability
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- User has deleted their subject information Flashcards on Factors Affecting Permeability/Structure, created by Deleted user on 05/03/2018.
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- Deleted user · Mar 2018
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- Mar 5, 2018
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- Created by Yinka F · Jan 28, 2018
- Copied by Yinka F · Mar 5, 2018
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