Question | Answer |
Describe the characteristics of a phospholipid bilayer | water soluble compounds unable to pass through.
important for maintaining Intra celluar fluid. |
what is 4 characteristics of a membrane? | -isolation
-regulates enviromental exchange
-sensitivity
-structural support |
membrane carbohydrates: | proteogycans, gyloproteins, glycolipids and glycocalyx. |
Membrane proteins | integral membrane - encased in membrane. Transmembrane protiens.
Peripherial proteins - inner or outter surface of membrane, |
Describe how proteins contribute to the structure and function of
the cell membrane | Anchoring proteins
–stabilise the cell
Recognition proteins
–immune response
Enzymes
–Peripheral and integral
Channels
–Gaps in membrane
–Allows movement of water and ions
–Molecule specific |
Explain why the cell membrane is more permeable to lipid soluble substances and
small molecules than to large water-soluble substances | |
Describe how the following mechanisms facilitate the transport of substances across
cell membranes:
–diffusion
–osmosis
–facilitated diffusion
–active transport
–endocytosis
–exocytosis | endocytos-
pinocytosis- cell drinking
phagocytosis - cell eating |
Describe the effects of isotonic, hypertonic and hypotonic solutions on cells | Isotonic solution(equal)
–Same solute concentration inside cell vs outside
Hypotonic solution (expand)
–Solute concentration inside cell highe rvs outside
Hypertonic solution (shrivel)
–Solute concentration inside cell lower vs outside |
Describe how carbohydrates contribute to the structure and function of
the cell membrane | –Lubrication and protection
–Anchoring and locomotion
–Specificity and binding
–Recognition |