B2 Cell transport systems

Question 1

Define diffusion?

Answer 1

The movement of a substance from a high concentration to a lower concentration

Question 2

Give two differences between active transport and facilitated diffusion.

Answer 2

Active transport requires energy/ATP whereas facilitated diffusion is passive. Active transport moves substances against the concentration gradient whereas facilitated diffusion moves substances down the concentration gradient.

Question 3

Give a similarity between active transport and facilitated diffusion.

Answer 3

Both use carrier proteins.

Question 4

Which type of molecule can diffuse across the phospholipid bilayer?

Answer 4

Non- polar or lipid soluble molecules.

Question 5

Through what structure do water soluble molecules cross the membrane?

Answer 5

Through channel proteins/aquaporins

Question 6

Which part of the phospholipid is hydrophobic?

Answer 6

Fatty acid tail.

Question 7

Protein molecules found on the surface of the membrane are called …

Answer 7

Extrinsic proteins

Question 8

Give 2 differences between a triglyceride and a phospholipid.

Answer 8

Phospholipids contain a phosphate group whereas triglycerides do not.Phospholipids have 2 fatty acids whereas triglycerides have 3 fatty acids.

Question 9

What is the function of the carbohydrates found on the outer surface of the membrane?

Answer 9

Antigens

Question 10

Each carrier protein can transport …. type of molecule.

Answer 10

One

Question 11

Name the two carbohydrate containing chemicals found in cell membranes.

Answer 11

Glycoproteins and glycolipid.

Question 12

What effect does cholesterol have on the fluidity of the membrane?

Answer 12

Reduces the fluidity/movement of phospholipids in the membrane.

Question 13

How can the structure of the membrane be changed to make the diffusion of water soluble molecules more rapid?

Answer 13

Increase number of channel proteinsIncrease surface area.

Question 14

Give three ways in which the rate of gas exchange can be increased.

Answer 14

Increase the surface area.Increase the concentration gradient.Decrease the diffusion pathway/distance Increase the temperature

Question 15

Why is the term fluid mosaic used to describe the model for membrane structure?

Answer 15

Fluid - phospholipid move within the membrane.Mosaic - proteins form blocks on the surface of the membrane.

Question 16

Define osmosis

Answer 16

Net movement of water from a high water potential to a lower water potential through a selectively/partially permeable membrane.

Question 17

Name a chemical that moves by osmosis into cells.

Answer 17

Water

Question 18

Name 2 molecules that move into cells and are used in respiration.

Answer 18

Oxygen and glucose

Question 19

What happens to ATP during active transport?

Answer 19

It is hydrolysed.A phosphate group is removed. Allowing the release of a small amount of energy.

Question 20

Name the components of a cell surface membrane

Answer 20

PhopsholipidsProteins (extrinsic and intrinsic)GlycoproteinsGlycolipidsCholesterol

Question 21

What are the functions of the phospholipids in the cell membrane

Answer 21

Allow non-polar molecules cross the membranePrevent polar molecules crossing the membraneMakes membrane flexible and self healing

Question 22

What are the functions of proteins in the cell membrane?

Answer 22

Provide structural supportAct as channels to transport polar molecules/facilitated diffusion

Question 23

What is the function of cholesterol in the cell surface membrane?

Answer 23

Reduces lateral movement of molecules in the membraneActs as a buffer against temperature changesPrevent leakage of water and dissolved ions from the cell

Question 24

What are the functions of glycoproteins in the cell surface membrane?

Answer 24

Act as recognition sites for hormones and neurotransmittersHelp cells attach and form tissues

Question 25

What happens to red blood cells if placed in pure water?

Answer 25

Swell and burst/undergo lysis

Question 26

What happens to a red blood cell placed in a strong sugar solution?

Answer 26

Shrinks

Question 27

Define active transport

Answer 27

The movement of molecules or ions against a concentration gradient using ATP and carrier proteins.

Question 28

What is the role of ATP in active transport?

Answer 28

Provide the energy needed to transplant a molecule against its concentration gradient.ATP binds to carrier protein, ATP is hydrolysed causing the protein to change shape, allowing the entry of the molecule/ion

Question 29

Name the molecule shown in the diagram

Answer 29

Triglyceride

Question 30

Name the components of this triglyceride

Answer 30

Glycerol

3 Fatty acids

Question 31

Name the strucutre shown on the diagram

Answer 31

Phospholipid bilayer

Question 32

Name the moelcule shown on the diagram

Answer 32

Phospholipid

Question 33

Name the componetns of a phospholipid

Answer 33

Glycerol

2 fatty acdis

1 phsopahte

Question 34

Describe the strucutre of this fatty acid

Answer 34

Monounsaturated fatty acid

One Carbon carbon double bonds in the hydrocarbon

Question 35

Describe this phopsholipid

Answer 35

Polyunsaturated

More than one carbon carbon double bond in the hydrocarbon

Question 36

Name the structure shown on the diagram

Answer 36

Cell membrane

OR

Plasma membrane

Question 37

Name structure G

Answer 37

Channel Protein

Question 38

Name strucutre F

Answer 38

Extrinsic protein

OR

Carrier protein

Question 39

Name structure E

Question 40

Name structure B

Answer 40

Glycolipid

Question 41

Name the molecule shown in the diagram

Answer 41

Steriod

OR

Oestrogen

Question 42

Name two steriods

Answer 42

Oestrogen

AND

Testosterone

Question 43

Give three functions of lipids in humans

Answer 43

Energy storage

Heat insulation

Protection of vital organs eg kidney

Question 44

Name two ways in which red blood cells can be calssified

Answer 44

ABO system

AND

Rhesus system

Question 45

Proteins and lipds in membranes can be glycosolated. What does this mean?

Answer 45

Carbohydrates are added to them.