cc3 - cell membranes and transport 2

how does temperature effect fasciliated diffusion*a higher temp means the molecules have more kinetic energy so there is a faster rate of diffusion

how does surface area effect fasciliated diffusion*a higher sa means there is more space for molecules to cross the membrane so there is a faster rate of diffusion

how does the steepness of the concentration gradient effect fasciliated diffusion*the bigger the difference in concentration the faster the rate of diffusion

how does the number of carrier proteins effect fasciliated diffusion*-it is the limiting factor

• the less protein carriers the slower the rate of fasciliated diffusion

gives two examples of molecules that are transported across the membrane by simple diffusion*- co2 and o2
-they are non polar and small

what type of R groups will be found in the region near the fatty acid tails of phospholipids*- non polar or uncharged R groups
-hydrophobic

define active transport*the active movement of molecules against the concentration via a carrier protein using energy in the form of ATP

what is the glycocalyx*the glycorproteins and glycolipids found in the cell membrane

what is a channel protein*an intricate protein with a pore that allows specific molecules to cross the membrane. it often gas a polar R group lining

what in an extrinsic protein*a protein found in the cell membrane that Is only found on one side of the membrane

what is the role of cholesterol in the cell membrane*regulates the fluidity of the membrane. only found in animal cells

what is a glycoprotein*a protein with a a small carbohydrate chain attached to the section facing out of the cell

what properties do molecules that move by simple diffusion have*they are non polar so they can react with the fatty acid tails
they are small so they can fit between the fatty acid tails

explain the difference between simple diffusion and facilitated diffusion*- in simple diffusion the molecule moves through the phospholipid bilayer
-in facilitated diffusion the molecule moves through a carrier or channel protein

define co transport*the movement of 2 different molecules across a membrane simualtnrously from a high to a low concentration. it is a from of facilitated diffusion

what is a glycolipid*a lipid with a small carbohydrate chain attached to the section facing out of the cell

how does temperate effect simple diffusion*a higher temperature means the molecules have more kinetic energy so there is a faster rate of diffusion

how does surface area effect simple diffusion*a higher surface area means there is more space for the molecule to cross the membrane so there is a faster rate of diffusion

how does steepness of concentration gradient effect simple diffusion*the bigger the difference in concentration the faster the rate of diffusion

how does the thickness of the membrane effect simple diffusion*thicker membranes leads to a slower rate of diffusion as it takes longer for the molecules to cross

why is the model of the structure of the cell membrane called the fluid mosaic model*fluid - the molecules can move laterally relative to each other
mosaic - ransom pattern of protein

what is the function of the glycocalyx*- cell to cell recognition
-receptors
-cell to cell signalling

what re the main complements of the cell membrane*phospholids arranged in a bilayer

what types of R groups will be found near the pore where molecules can pass through*-polar or charged
-hydrophilic

what are the 3 functions of the cell membrane*-controls what enters and leaves the cell
-cell recognition
-secretes chemicals

what are the examples of the instrict proteins*carrier and channel prtieisn

how does lipid solubility effect diffusion*fat soluble molecules are non polar and diffuse most rapidly across a membrane than water molecules which are polar

what is endocytosis*-cell membrane folds around the particle, until the particle is engulfed by the membrane

• the invagination of the membrane forms a vesicle
  -needs ATP

what is exocytosis*-the vesicle fuses with the cell membrane
-contents are released outside
-needs atp
-gets rid of large waster products

osmosis defintion*the passive movement of water from an area of higher water potential to an area of lower water potential across a selectively permeable membrane

what is water potential*Measure of the tendency of water molecules to move from one region to another

what is water potential the combination of*pressure potential and solute potential

what is the bursting of a cell called*osmotic lysis

what is it called when a cell shrivels*crenate

what does a cell wall mean for osmotic changes*it resists osmotic changes preventing lysis

what happens when a lot of water enters the plant cell*it becomes turgid

what is it called when a plant cell is put in an isotonic solution*it is said to be flaccid

what is it called when a plant cell is put into a hypertonic solution*plasmolysed - the cell membrane pulls away from the cell wall

what does isotonic mean*the water potential is the same

what is incipient plasmolysis*-effect produced by placing plant cells in an isotonic solution
-causes the cell membrane to pull away from the cell wall in some areas
-cell is neither plasmolysed or turgid

what is pressure potential*the pressure the cells all exerts on the cytoplasm and vacuole it is inelastic

what is a glycoclax*a glycoprotein and glycolipid coating surrounding the cell membranes of some cells

how does temperature effect the phosophoslipid bilayer*-phospholids have more kinetic energy
-move more fluidly and higher speeds
-crwates gaps substances can diffuse through
-when proteins denature this creates pores

what is the solute potential*it is the concentration of solutes in cytoplasm and vacuole - always negative

what are the principle components of the plasma membrane*-intracellular and extracellular proteins
-glycoproteins
-phospholipids
-cholesterol

intrinsic proteins*proteins found within the phosopholipfs bilayer. includes channel and carrier proteins

What are the functions of intrinsic proteins?*-structrual support
-carry water soluble molecules across the phospholipid bilayer
-form ion channel to enable active transport

functions of an extrinsic protein*-receptors
-acts as antigens enabling cell recognition
-help cells adhere to each other

factors effecting permeability of plasma membrane*temperature, organic solvents, ph

How does temperature affect the permeability of the plasma membrane?*as temperature increases the phospholipids have more kinetic energy and move more increasing the fluidity and permeability of the plasma membrane

what happens to the plasma membrane when the temperature becomes too high*-channel and carrier protein will become denatured effecting membrane permeability
-the cell will eventually break down completely

how do organic solvents affect the permeability of plasma membranes*-dissolve the membrane disrupting the cells
-increaces the fluidity and permeability of the plasma membrane

Define diffusion*the passive movement of small non polar lipid soluble molecules from an area of high concentration and area of low concentration

what is pressure potential*hydrostatic pressure from the cell contains pushing on the cell wall. the value is 0 or positive. when there is more water the pressure potential is higher

why is it called a phosophilid bilayer*-phosophilipids align themselves in a bilayer due to the nature of the components of a phospholipid. the phosphate head is polar which makes them hydrophilic, therefore they ar repositioned outside with aqueous environments inside and outside the cell membrane. the fatty acid tails re non polar which makes them hydrophobic. therefore they are positioned away from aquatic environment.

what would a graph depicting simple diffusion and extracellular concentration look like?*-positive linear correlation between concentration and rate of uptake
-in simple diffusion non polar molecules move from high to low concentration
-therefore as concentration of molecules increase more diffuse across the phopsholid bilayer

what would a graph depicting facilitated diffusion and extracellular concentration look like?*-at a low concentration there is a linear positive correlation.

• the rate of uptake platues out and reaches a maximum rate of uptake
  -in facilitated diffusion molecules move passively from high to low concentration through channel or carrier proteins
  -the number of channel and carrie proteins will bit change as extracellular concentration increaces so it will reach a maximum when they are all saturated and at maximum capacity

facilitated diffusion*the net movement of substances from a high concentration to a lower concentration through the use of transport proteins without the use of energy

how does cyanude affect active transport*-inhibits the production of ATP
-this prevents active transport