Cell membrane and transport Flashcards
(15 cards)
Hypertonic & hypotonic
If the cell is hypertonic to a solution, the cell will absorb water by osmosis as there is a higher water potential outside
If the cell is hypotonic to a solution, the outside solution will absorb water from the cell by osmosis as there is a higher water potential inside the cell
Oxygen being transported shape on graph
Oxygen passes through phospholipid by layer because it’s nonpolar.
Line is directly proportional between the concentration gradient and rate of diffusion
Glucose being transported shape on graph
Glucose uses carrier/channel proteins as it’s polar
The rate is eventually limited by the number of carrier/channel proteins available - curves off
What is the term that describes a solution when 50% of the cells are plasmolysed
Incipient plasmolysis
What is the pressure potential of the cells when they are in this condition?
Zero
Describe what is shown when a graph measuring the water potential levels of
Equilibrium is reached it is isotonic so no net movement of water
Why the growth of a seedling may be reduced if the solution does not have an air bubble through it
Oxygen is required
No ATP is produced
Active transport cannot occur fewer ions can be transported against the concentration gradient
Stunted growth because of a lack of ions for example phosphate required to make DNA and proteins essential for growth
phospholipid bilayer
Diffusion of small molecules
Why is there more channel proteins in the mitochondria membrane than in the cell surface membrane?
More facilitated diffusion in the mitochondria
The effect of endocytosis and exocytocis on the total surface area of the infected cell
Endocytosis results in membrane being added and surface area being increased
Exocytosis results in membrane being lost and surface area being decreased
Trend on a graph of osmosis in potatoes when exposed to a solution with sucrose
At lower concentrations, the mass increases
Water moves in because the water potential of solution outside the cells is higher than inside
When the line crosses the axis, there is no change in mass
The water potential of the solution inside and outside the cell is the same so there is no net movement of water
At higher concentrations, the mass decreases
Water moves out because the water potential of solution outside the cells is now lower than inside
Trend on the graph if a sweet potato was used
Sweet potato contains more sugar
Sweet potato have a lower water potential than potato
The concentration of sucrose at which there is no change in mass is higher in a sweet potato than in the potato
Gain a mass is greater at lower concentrations of sucrose in sweet potato
Animal tissue osmosis
Animal tissue would decrease in mass or lose water if placed in solution of lower water potential
There would be no change in mass if the external solution is isotonic
If the external solution has a higher water potential compared to tissues, water would enter the cells
Cell would burst as there is no cell wall
What membrane is more permeable to small molecules
A membrane with bigger spaces between phospholipids which are less densely packed
How does acid and ethanol affect the membrane
Acid denatures the proteins
Ethanol dissolves the phospholipids
