Lipids and Membranes Flashcards
1
Q
What are some examples or lipids?
A
- sterols
- fats, oils and waxes
- phospholipids
2
Q
What is the function of lipids?
A
- energy storage (fats and oils)
- protective coatings (waxes)
- structure (membranes)
- chemical messengers (eg sterol)
3
Q
what other components are in the phospholipid bilayer?
A
- proteins
- glycoproteins
- sterols
4
Q
triglycerides
A
- three fatty acids joined to glycerol via ester bond
5
Q
fats vs oils
A
FAT - triglyceride that is solid at room temp
OIL - liquid at room temp
6
Q
4 movements across cell membrane INTO the cell
A
- diffusion
- facilitated diffusion
- active transport
- pinocytosis and phagocytosis
7
Q
Osmosis
A
- net movement of water, through a semi-permeable membrane, from a region of low to a region of high solute concentration
8
Q
osmotic potential
A
- water moves from higher to lower potential during osmosis
- the higher the solute concentration, the more negative the potential
9
Q
liquid hypertonic to cell
A
when solute concentration outside the cell is higher causing cell to shrink due to net movement OUT of the cell
10
Q
plant cell in distilled water
A
- cells stiffens but retains shape
- does not burst due to rigid cell wall
11
Q
cell in saturated salt solution
A
- cell body shrinks and pulls away from cell wall
12
Q
role of membrane proteins and glycoproteins
A
- enzymatically active
- structural role
- identify self and non-self
- surface receptors
- transport mechanism
- selective barrier
13
Q
Active transport
A
- movement against concentration gradient
- uses ATP
- usually coupled with other reactions
14
Q
phagocytosis
A
- membrane bends to engulf surrounding material
- forms a bubble (phagosome) containing digestive enzymes
15
Q
integral proteins
A
- can be transmembrane (crossing the whole membrane)
or - can be penetrated partially in the membrane
- different to peripheral proteins
