Transport In Cells

Question 1

Why do cells need transport

Answer 1

Require a supply of chemicals (e.g glucose and oxygen ) for cellular respiration and other reactions
Waste products need to be removed before they can damage them

Question 2

Cell surface membrane purpose

Answer 2

Controlling the transport of materials into and out of the cell
Control transport within the cells e.g er and the Golgi apparatus membrane bound that move substances in the cell

Question 3

Components of the cell surface membrane

Answer 3

Glycoproteins
Proteins
Lipid bilayer

Question 4

Glycoproteins purpose

Answer 4

Act as antigens
Cell recognition
Receptors for hormones or neurotransmitters
Set up reactions within cell

Question 5

Peripheral proteins purpose

Answer 5

May be enzymes

Involve in regulating transport e.g cell signalling

Question 6

Membrane bilayer

Answer 6

Bilayer of phospholipids and other polar lipids
Polar heads inside and outside cell
Hydrophobic lipid fore
Contains integral proteins

Question 7

Pore

Answer 7

Hydrophilic channel

Question 8

Integral proteins

Answer 8

Main transport system form either permanent pores or other transport mechanisms e.g carrier proteins or active pumps involving enzymes

See fig A pg212

Question 9

Fluid mosaic model

Answer 9

Phospholipid sea with associated proteins floating or anchored

Question 10

Passive transport

Answer 10

Result of concentration , pressure or electrochemical gradients and involves no energy from the cell

Question 11

Active transport

Answer 11

Moving substance into or out of the cell using adenosine triphosphate atp produced in cellular respiration

Question 12

Diffusion

Answer 12

Movement of particles in a liquid or gas down a concentration gradient . Move from relative high concentration to area or relative low concentration result of random movements
Cell membranes are no barrier to diffusion of small particles e.g. oxygen or carbon dioxide

Question 13

Facilitated diffusion

Answer 13

Diffusion that takes place through carrier proteins or protein channels
Protein lined prices of cell membrane make it possible

Question 14

Osmosis

Answer 14

Special form of diffusion
Movement of solvent molecules (usually water ) down a concentration gradient through a partially permeable membrane
Partially permeable solutes accumulate either side of the membrane and results in the movement of water

Question 15

3 active transport mechanisms

Answer 15

Endocytosis
Exocytosis
Active transport

Question 16

Endocytosis

Answer 16

Movement of large molecules into cells through vesicle formation

Question 17

Exocytosis

Answer 17

Movement of large molecules out of cells through vesicle formation

Question 18

Active transport

Answer 18

Movement of substances across the membrane of cells using ATP
Proteins in the membrane act as carriers or enzymes making ATP available to move ions or molecules