Cell Membranes

Front 1

What does the fluid mosaic model describe?

Back 1

Arrangement of molecules in the membrane.

Front 2

What are the two different types of proteins in a fluid mosaic model?

Back 2

channel protein and carrier proteins?

Front 3

What do channel and carrier proteins do in the in the membrane?

Back 3

Transport large molecules and ions across the membrane.

Front 4

What is a protein with a carbohydrate called?

Back 4

glycoprotein.

Front 5

what is a lipid with a carbohydrate called?

Back 5

glycolipid.

Front 6

What are all the different components of the fluid mosaic model?

Back 6

Glycoprotein

Glycolipids

phsopholipids

protein channel

protein

cholseterol

Front 7

What are the two different things that phospholipids are made out of?

Back 7

a head and a tail.

Front 8

which part of the phospholipid is hydrophobic?

Back 8

tail.

Front 9

Which part of the phospholipid is hydrophilic?

Back 9

head.

Front 10

In a fluid mosaic model is the centre of the bilayer hydrophobic or hydrophilic and explain what this means in terms of substances diffusing?

Back 10

The centre is hydrophobic which means that water soluble substances cant diffuse through it.

Front 11

What does the cholesterol do for the membrane?

Back 11

it gives the membrane stability by fitting in between the phospholipids . Cholesterol binds to the hydrophobic tails of the of the phsopholipids which causes them to pack more tightly closer. Makes the cell less fluid and more rigid.

Front 12

How does temperature affect membranes below 0C?

Back 12

This means that the phospholipids dont have much energy meaning that they are closely and tightly packed together. Proteins denature increasing permeability. When temperature is this low, ice crystals may form and pierce the membrane making it highly permeable when it thaws.

Front 13

How does temperature affect membranes when it is between 0 and 45?

Back 13

This will allow the phospholipids to move around as they will have a lot more energy. higher the temperature the higher the pearmability.

Front 14

How does temperature affect membranes when above 45?

Back 14

Phospholipid bilayer starts to melt down and membrane becomes more permeable.Channel proteins and carrier proteins denature meaning that they cant transport large molecules.

Front 15

What is the definition of diffusion?

Back 15

Diffusion is the movement of particles from an area of high concentration to an area of low concentration.

Front 16

Is difusion a passive process?

Back 16

yes because it requires no energy,

Front 17

What are all the factors that can affect the rate of diffusion?

Back 17

Concentration gradient- The higher the concentration gradient the higher the rate of diffusion.

The thickness of surface- The thinner the surface the higher the rate of diffusion as their is a smaller distance to travel.

Surface area- The Larger the surface area, the higher the rate of diffusion.

Front 18

What is facilitated diffusion?

Back 18

This is when Large molecules or charged particles diffuse through a carrier protein or a channel protein.

Front 19

What do carrier proteins transfer and how do they do this?

Back 19

They transport Large molecules.They do this by attaching a large molecule to the protein and then the protein changes shape and releases the molecule on the other side of the membrane.

Front 20

What do channel proteins transfer and how do they do this?

Back 20

They transfer charged particles. They do this by forming pores in the membrane for charged particles to diffuse through.

Front 21

What are the factors affecting the rate of facilitated diffusion and explain how.

Back 21

The Higher the concentration gradient the higher the rate of facilitated diffusion.

The higher the amount of channel and carrier protein, the higher the rate of facilitated diffusion as more molecules can transport across.

Front 22

The definition of osmosis?

Back 22

This is the diffusion of water molecules across a partially permeable membrane from an area of high water concentration to an area of low concentration.

Front 23

What is the water potential of pure water?

Back 23

zero.

Front 24

What happens when you add solutes to pure water?

Back 24

Water potential decreases.

Front 25

What does a more negative water potential mean?

Back 25

That the water has a strong concentration of solutes.

Front 26

What is it called when two solutions have the same water potential?

Back 26

isotonic.

Front 27

What is it called when a cell is placed in a solution with a higher water concentration?

Back 27

hypotonic.

Front 28

What is it called when a cell is placed in a solution with a lower water concentration?

Back 28

hypertonic.

Front 29

What happens when a cell is placed in an isotonic solution and explain why.

Back 29

Nothing because the water concentration is the exact same meaning that there will be no movement of water.

Front 30

What happens when a cell is placed in a hypertonic solution and explain why?

Back 30

Water moves out of the cell so the cell starts to shrink as their is a higher water concentration on the outside than the inside.

Front 31

What happens when a cell is placed in a hypotonic solution and explain why?

Back 31

Water moves into the cell as their is a lower concentration in the cell causing the cell to swell.

Front 32

What are the factors affecting the rate of osmosis and explain how.

Back 32

The water potential gradient- The higher the water potential gradient the higher the rate of osmosis.

The thickness of exchange surface- The thinner the surface area the faster the rate of osmosis as their will be a smaller distance to travel.

The surface area- The bigger the surface area the higher the rate of osmosis.

Front 33

What is active transport?

Back 33

Active transport uses energy to move molecules and ions across membranes from an area of low concentration to an area of high concentration.

Front 34

how does carrier proteins work in active transport?

Back 34

They attach to a molecule, change shape and transport it to the other side of the membrane.

Front 35

What is the difference between facilitated diffusion and active transport?

Back 35

The difference is that active transport is not passive and used energy. Plus, facilitated diffusion moves down the concentration gradient, whereas active transport moves across the concentration gradient.

Front 36

What is a co transporter?

Back 36

This is a type of carrier protein.

Front 37

How do co transporters work?

Back 37

They work by binding on two molecules at the same time and one of the molecules is used to move the other one against its concentration gradient.

Front 38

What are the things that affect the rate of active transport and explain how.

Back 38

Speed of carrier protein- the faster they work the faster the rate of active transport.

Number of carrier proteins present- More proteins mean