Form and function: Cells

Question 1

Osmosis

Answer 1

Net movement of water across a partially permeable membrane from an area of lower solute concentration to an area of higher solute concentration

Question 2

Diffusion

Answer 2

The net movement of molecules from a region of high concentration to a region of low concentration down a concentration gradient
This directional movement along a gradient is passive and will continue until molecules become evenly dispersed
Only small and non polar molecules will be able to freely diffuse

Question 3

integral proteins

Answer 3

proteins that penetrate the phospholipid bilayer to remain permently attached to the membrane
these trans membrane proteins cannot be readily isolated without disrupting the bilayer

Question 4

Peripheral proteins

Answer 4

Only temporarily linked to the membrane
are either attached to integral proteins, linked to polar phospolipid heads or held by the cytoskeleton

Question 5

Membrane proteins

What does JETRAT stand for in membrane transport?

Answer 5

Junctions
Enzymes
Transport
Recognition
Anchorage
Transduction

Question 6

Membrane proteins

Junction

Answer 6

serve to connect and join two cells

Question 7

Membrane proteins

Enzymes

Answer 7

fixing to membrane to localises metabolic pathways

Question 8

Membrane proteins

Transport

Answer 8

Responsible for facilitated diffusion and active transport

Question 9

Membrane proteins

Recognition

Answer 9

Many functions as markers for cellular identification

Question 10

Membrane proteins

Anchorage

Answer 10

attatchment point for cytoskeletons and extra celluar matrix

Question 11

Membrane proteins

Transduction

Answer 11

function as receptors for peptide hormones

Question 12

Aquaporins

Answer 12

Channels that allow the passage of water but not other substances

Question 13

Faciliated diffusion

Answer 13

the passive movement of molecules across a cell membrane via the aid of a membrane protein. used by molecules that are unable to freely cross the phospholipid bilayer

Question 14

Chanel Proteins

Answer 14

have tiny pores which act as pathways for ions
these chanels are highly selectie due to the binding sites of the hydrophilic amino acids side chains lining the chanels being highly specific and the size of a pore

Question 15

What are some stimuli for gated chanel proteins?

Answer 15

changes in voltage across the membrane (voltage gate chanels)
binding a small molecules to the channel protein (ligand-gated channels)
mechanical forces

Question 16

Carrier proteins

Answer 16

bind to solute molecules
undergo a comformational change
transfer molecules to the otherside of the membrane

Question 17

Active transport

Answer 17

uses ATP to move molecules against a concentration gradient

Question 18

Membrane transport

Protein pumps

Answer 18

used to move molecules against the contration gradient

Question 19

Direct active transport

Answer 19

where the energy released by a reaction is used for directly for active transport

Question 20

Process of direct active tranport

Answer 20

a specific solute will bind to the protein pump on one side of the membrane
the hydrolysis of ATP causes a comformation change in a protein pump
the solute molecule is translocated across the membrane

Question 21

Indirect active transport

Answer 21

where the movement of one solute down it’s concentration gradient drives the movement of the second solute against it’s concnetration gradient

Question 22

Functions of Glycoproteins/glycolipids

Cell recognition

Answer 22

act as markers and help regonise each other, it also helps the immune system regonise forgein cells

Question 23

Functions of Glycoproteins/glycolipids

Cell adhesion

Answer 23

both glycolipids and glycoproteins help cells attach and bind to other cells to form tissues

Question 24

Functions of Glycoproteins/glycolipids

Cell signalling

Answer 24

they act as receptors for an enzymes and other molecules in helping in cell signalling

Question 25

Glycolipids

Answer 25

they are attached to the phospholipids/fatty acid chains
they are amphipatic (hydrophobic and phylic at the same time) - the carbohydrate group of these molecules are polar and extend into the extra cellular enviroment and the nonpolar lipid is in the bilayer

Question 26

Glycoprotein

Answer 26

the covalent bonding of short carbohydrate chains to the protein molecules results in formation of glycoprotein. the carbohydrate groups of the glycoproteins often stick out into the extracellular enviroment

Question 27

Glycocalyx

Answer 27

the sticky layer formed y carbohydrate group of the gycolipids and glycoproteins that protrude from the cell surface. Glycocalyx in addition to its roles in cell signalling, cell adhesions, and cell recognition, helps in protecting the cell surface