Biological Membranes model answers revision.

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  • Created by: ElishaG
  • Created on: 21-03-17 20:54
State the components of the plasma membrane.
1)Phospholipids.2)Proteins.3)Glycoproteins.4)Cholesterol.5)Glycolipids. (Learn to label diagram).
1 of 17
State the function of cholesterol in the plasma membrane.
1)Stabilise the membrane.2)Maintain fluidity.3)Reduces permeability to polar/charged particles.
2 of 17
State the function of phospholipids in the plasma membrane.
1)To act as a barrier to polar/charged particles.2)To allow the passage of non-polar/lipid soluble particles.3)Select what enters or leaves cell.
3 of 17
Describe the functions of glycoproteins in the cell surface/plasma membrane.
1)Acting as antigens.2)Recognition of cells as self/non-self.3)Cell signalling.4)Receptor/binding site for hormone,drugs etc.5)Trigger on transport proteins.6)Cell adhesion/holds cells together.7)Attach to water molecules to stabilise membrane.
4 of 17
What is meant by the term active transport?
1)Movement of substances against the concentration gradient from low to high concentration ydin
5 of 17
Explain what happens to a plant cell placed into a solution of high water potential?
1)Water moves into cell by osmosis.2)Cell has lower water potential than surrounding solution.3)Water moves down water potential gradient from high to low water potential.4)Plant cell becomes turgid.
6 of 17
Explain why plant cells do not burst.
1)Cell wall-provides strength and can withstand internal pressure so prevents cell membrane over expanding.2)Limits uptake of water.
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Explain what happens to a plant cell placed into a solution of low water potential.
1)Water moves out of cell by osmosis.2)Cell has higher water potential than surrounding solution.3)Water moves down water potential gradient from high to low water potential.4)Plant cell plasmolyses.
8 of 17
Explain what happens when an animal cell is placed into a solution of high water potential.
1)Water moves into cell by osmosis.2)Cell has lower water potential than surrounding solution.3)Water moves down water potential gradient from high to low water potential.4)Animal cell bursts/lysis.
9 of 17
Explain what happens when an animal cell is placed into a solution of lower water potential.
1)Water moves out of cell by osmosis.2)Cell has higher water potential than surrounding solution.3)Water moves down water potential gradient from high to low water potential.4)Animal cell crenates.
10 of 17
Outline the ways in which substances can enter a cell through the plasma membrane.
1)Small, non polar substances diffuse-phospholipid bilayer.2)Large substances travel via carrier proteins.Polar substances travel via channel proteins-both by facilitated diffusion.3)Active transport-carrier proteins-ATP needed.4)Bulk-endocytosis.
11 of 17
Describe how water molecules move through the plasma membrane.
1)Fit between phospholipids/through phospholipid bilayer via protein channels called aquaporins.
12 of 17
Describe and explain cell signalling.
1)Communication between cells.2)Signal molecule released by exocytosis.3)Binds to receptor/glycoprotein on plasma membrane.4)Receptor and signal molecule are specific.5)Signal molecule and receptor have complementary shapes-response triggered.
13 of 17
State the roles of membranes inside cells.
1)Isolation of reactions.2)Site for attachment of enzymes/ribosomes.3)Provide selective permeability.4)Creation of concentration gradients.5)Control what enters/leaves organelles.6)Isolates DNA.7)Forms vesicles.8)Intracellular transport.`
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State the roles of membranes at the surface of cells.
1)Separate cell.2)Entry/exit of molecules.3)Phospholipid bilayer-allows passage of non polar molecules.4)Aids facilitated diffusion via channel/carrier proteins.5)Aids active transport via carrier proteins.6)Endocytosis/exocytosis.7)Receptors.
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Suggest changes that occur to the plasma membrane at high temperatures.
1)Membrane structure disrupted.2)Phospholipid bilayer becomes more fluid.3)Membrane proteins denatured/unable to function.4)Membrane becomes more permeable.
16 of 17
State how root epidermal cells take up minerals from the soil and describe how they are specialised to maximise absorption.
1)Active transport/uptake.2)Cells have extensions/hairs.3)Thin cell wall.4)Large/increased surface area.5)Many more mitochondria.6)Many carrier proteins in cell surface membrane.
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Other cards in this set

Card 2

Front

State the function of cholesterol in the plasma membrane.

Back

1)Stabilise the membrane.2)Maintain fluidity.3)Reduces permeability to polar/charged particles.

Card 3

Front

State the function of phospholipids in the plasma membrane.

Back

Preview of the front of card 3

Card 4

Front

Describe the functions of glycoproteins in the cell surface/plasma membrane.

Back

Preview of the front of card 4

Card 5

Front

What is meant by the term active transport?

Back

Preview of the front of card 5
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