Chapter 7 Functions of membranes, fluid mosaic model

Question 1

What is the structural & function of the boundary of the cell?

Answer 1

The membranes provide a structural framework or anchor site for many enzyme, biochemical rxns, & and pathways, membranes play a important role in the biochemistry of living organisms

Question 2

What are the organelles of the membrane?

Answer 2

receptors

Question 3

what is the thing that is separating “what’s in” from “what’s out”?

Answer 3

The membrane

Question 4

what is selective permeability?

Answer 4

The regulation which substrates can pass through the membrane and what cannot.

Question 5

What biochemical role does membranes play in living organisms?

Answer 5

To have a structural framework or anchor site for many enzymes, biochemical rxns and pathways.

Question 6

What is the point of receptors and other structures on the membrane surface?

Answer 6

to receive information signals from the surrounding environment.

Question 7

What did Charles Overton discover?

Answer 7

That membranes are basically a lipid substance

Question 8

What did Longmuir state?

Answer 8

That lipids are phospholipids

Question 9

What did Gortner and Grendel discover?

Answer 9

That phospholipids form a lipid bilayer, that there are hydrophilic “polar heads” on the outside and non-polar hydrophobic tails on the inside.

Question 10

What did Davson and Danielli find?

Answer 10

That membranes contain proteins “protein sandwich made” which are just proteins on the outside on both sides of the bilayer.

Question 11

What did Robertson discover about cell membranes?

Answer 11

The “unit membrane” - are membrane function as a inseparable unit, meaning membranes cannot be partial and still be functional

Question 12

What did Singer and Nicholson create?

Answer 12

The fluid mosaic model

Question 13

What is the two dimensional fluids of membranes composed of?

Answer 13

A lipid bilayer - “fluid”, proteins embedded in the lipid bilayer like pieces of mosaic, lipids and proteins that flow laterally, 2 membranes that are asymmetric - that the two monolayers are composed of diffferent lipids and proteins, and there are two faces.

Question 14

What are the two faces?

Answer 14

exoplasmic face (E-Face) - which faces “outside”, and protoplasmic face (p-face) - is the cytoplasmic face (c-face) faces inside

Question 15

How do lipids and proteins flow?

Answer 15

They flow laterally

Question 16

What is the characteristic of the 2 membranes? And what are they composed of?

Answer 16

They are asymmetric, the two monolayers are composed of different lipids and proteins.

Question 17

What is the lipid bilayer composed of?

Answer 17

It is composed of two monolayers “leaflet” that have hydrophilic polar heads and hydrophobic polar tails.

Question 18

What is Hydrophobic force?

Answer 18

It is what holds the bilayer together

Question 19

What is a phospholipid composed of?

Answer 19

a hydrophilic head and a hydrophobic tail

Question 20

What consists of the peripheral proteins?

Answer 20

a lipid anchored membrane protein that is covalently bonded, and one that is noncovalent.

Question 21

What are integral proteins and what does it consist of?

Answer 21

They are proteins that are partially or all the way through the bilayer, they consist of monotopic proteins that stay in one monolayer, and trans-membrane proteins which go all the way through the bilayer

Question 22

What are the different types of transmembrane proteins?

Answer 22

They are transport proteins, channel proteins, and carrier proteins

Question 23

What is a channel protein?

Answer 23

they are proteins that are able to move small inorganic molecules or ions by facilitated diffusion

Question 24

What are the transport proteins?

Answer 24

They facilitate passage of chemicals through the membrane

Question 25

What is Uniport?

Answer 25

It is the movement of one molecule in one direction through the bilayer using facilitated diffusion.

Question 26

What does symport do?

Answer 26

The movement of 2 molecules in the same direction one is passively by facilitated diffusion and the other is by piggy back.

Question 27

What does antiport?

Answer 27

It is the movement of 2 molecules in opposite directions one is passively by facilitated diffusion, but it generates energy that then drives the other by active transport.

Question 28

What does the transport ATPase pump do?

Answer 28

It uses ATP hydrolysis to move a molecule through the transport protein

Question 29

What is the aspect that is in the monolayer that is found only in a animal cell? what is its characteristic?

Answer 29

Cholesterol, the characteristic is its fluidity

Question 30

What type of things go through the transport proteins? what are the type of channel proteins for them?

Answer 30

Molecules and Ions, for molecules there are porins and aquaporins, and for ions they are ion channels

Question 31

What are carrier proteins?

Answer 31

Also known as transport permease, they move large organic molecules by various mechanisms such as passive facilitated diffusion or by active transport, except never by ATP hydrolysis.

Question 32

What is produced when ATP + H2O? and what catalyzes it?

Answer 32

ADP + Pi and ATPase catalyzes it