WorksheetsAQA A-Level Biology CH5. Transport Across Membranes
Total questions: 51
Worksheet time: 18mins
Suggest a function/s of the membrane surrounding the chloroplasts?
to keep the enzymes needed for photosynthesis all in one place
controls the release of ATP from the organelle
making photosynthetic reactions more efficient
to compartmentalise photosynthesis
Suggest a function/s for the membrane surrounding a bacterial cell.
to stop WBC's from entering and destroying the bacterial cell
to control what substances enter and leave the cell
to enable cell signalling
making photosynthetic reactions more efficient
A model was suggested to describe the arrangement of the molecules in a membrane. What is the name of this model?
Magic Fluid Model
Mosaic Fluid Model
Fluid Mosaic Model
Phospholipid Mosaic Model
Proteins are scattered through the bilayer, like tiles in a mosaic. What is label B known as?
peripheral protein
glycoprotein
carrier protein
channel protein
Proteins are scattered through the bilayer, like tiles in a mosaic. What is label E known as?
peripheral protein
channel protein
carrier protein
glycoprotein
Write the name for the receptor protein on the cell-surface membrane (label F)
(a)
Which two molecules make up the cell membrane?
Protein and Lipids
Protein and Phospholipids
Starch and Protein
Protein and Glucose
Which label identifies the peripheral protein?
B
C
D
E
Phospholipids form a barrier to dissolved substances. They have a 'head' and 'tail'? What is label G?
Head - hydrophilic
Head - hydrophobic
Tail - hydrophilic
Tail - hydrophobic
Phospholipids form a barrier to dissolved substances. They have a 'head' and 'tail'? What is label H?
Head - hydrophilic
Head - hydrophobic
Tail - hydrophilic
Tail - hydrophobic
What molecule has been circled in the image?
(a)
Define the terms - hydrophobic and hydrophilic
hydrophobic - attracts water
hydrophobic - repels water
hydrophilic - attracts water
hydrophilic - repels water
What is a glycoprotein?
a protein with a carbohydrate attached
a protein with a lipid attached
a protein with a glucose molecule attached
a protein with starch attached
Explain why a cell-membrane is an effective barrier against water-soluble substances
the centre of the phospholipid bilayer is hydrophilic so the membrane does not allow water soluble substances through it
the centre of the phospholipid bilayer acts like a vacuum that does not allow any substances through it
the centre of the phospholipid bilayer is hydrophobic so the membrane does not allow water soluble substances through it
the molecules within the membrane are constantly moving in a fluid motion so will block molecules entering through the membrane
Describe the role of cholesterol in the membrane?
provides the membrane with a source of energy to burn so ATP can be produced to help with active transport
maintains the shape of animal cells and creates a barrier to polar substances
allows the passage of small molecules that would find it difficult to pass through the membrane
helps make the membrane less fluid and more stable
What is diffusion?
the net movement of substances from an area of high concentration to an area of low concentration
the net movement of substances from an area of low concentration to an area of high concentration with energy
the net movement of substances through a semi-permeable membrane from an area of high concentration to an area of low concentration
the net movement of substances from an area of low concentration to an area of high concentration
Is simple diffusion a passive or active process?
(a)
Give three (3) factors that affect the rate of simple diffusion.
concentration gradient
mass of the substance
surface area
time
thickness of the exchange surface
Is facilitated diffusion a passive or active process?
(a)
Describe how a channel protein transports molecules across a cell membrane.
carrier proteins detect chemicals that are released from other cells, the chemical signal to the cell to respond in some way
forms a pore in the membrane for charged particles to diffuse through via facilitated diffusion
a molecule attaches to the protein, it changes shape and releases the molecule on the opposite side of the membrane
restrict the movement of the cell membrane to keep it rigid
Describe how a carrier protein transports molecules across a cell membrane.
carrier proteins detect chemicals that are released from other cells, the chemical signal to the cell to respond in some way
forms a pore in the membrane for charged particles to diffuse through via facilitated diffusion
a molecule attaches to the protein, it changes shape and releases the molecule on the opposite side of the membrane
restrict the movement of the cell membrane to keep it rigid
The picture is an example of _________________.
osmosis
facilitated diffusion
diffusion
active transport
Some molecules need the help of membrane proteins to move molecules from areas of high concentration to areas of low concentration.
active transport
facilitated diffusion
diffusion
osmosis
Small polar molecules like O2 and CO2enter a cell through
simple diffusion
osmosis
facilitated diffusion
phagocytosis
Based on the diagram, what type of process occur?
Diffusion
Active Transport
Simple Diffusion
Osmosis
The fluid mosaic model describes a membrane consisting of
a phospholipid bilayer with embedded proteins
2 layers of phospholipids with proteins in between
individual proteins and phospholipids that can drift
both a and c
When animal cells are placed in a __________ solution they begin to swell.
Hypertonic
Isotonic
Hypotonic
Concentrated
Define the term - water potential
the potential of water molecules to only diffuse into the solution
the potential of water molecules to diffuse out of or into solution
the potential of energy to be released contained in the bonds of the water molecules
the potential for water to be whatever it can be during its water cycle
If two solutions have the same water potential they're said to be.....
hypertonic
hypotonic
isotonic
Solutions with a higher water potential compared with the inside of a cell are called (a)
Solutions with a lower water potential than the cell are called (a)
Give three (3) factors that affect the rate of osmosis.
thickness of the exchange surface
temperature
surface area
water potential gradient
pressure
Diagram shows the movement of molecule M across the plasma membrane through process X. What is process X?
simple diffusion
facilitated diffusion
osmosis
active transport
The movement of substances from low concentration region to high concentration region across a plama membrane is known as
simple diffusion
active transport
facilitated diffusion
osmosis
Absorption of glucose and amino acids in the
villus occur through
active transport
facilitated diffusion
osmosis
simple diffusion
Reabsorption of water occurs by _______
through the renal tubule in the kidney
active transport
simple diffusion
osmosis
facilitated diffusion
Which of the following statement is true about active transport?
Occurs against the concentration of the gradient
Requires energy
Occurs until a dynamic equilibrium is achieved
Occurs following the concentration of the gradient
An example of pump transport is
glucose transport
osmosis
Na+/K+ Pump
CO2 + O2 Transport
[RPA Investigating Membrane Permeability] What is the function of a colorimeter?
a machine that passes light of a specific wavelength through a liquid and measure how many calories it absorbs
a machine that passes light of a specific wavelength through a liquid and measure how much light is absorbed
a machine that passes light of a specific wavelength through a liquid and measures which colours have been reflected
a machine that passes light of a specific wavelength through a solid and measure how much light is absorbed
[RPA Investigating Membrane Permeability] When you're handling cuvettes you need to ......
wipe away any marks
wipe away any moisture on the outside of the cuvette
gently tap on the side to remove any air bubbles
all of the above
[RPA Investigating Water Potential] What is a serial dilution?
when you create a set of solutions that decrease in concentration by an exponential factor each time
when you create a set of solutions that decrease in concentration by the same factor each time
when you create a set of solutions that increase in concentration by the exponential factor each time
when you create a one of solution that contains a serial number attached and can be scanned and logged onto a data logger
