Lecture 4

Question 1

main components of Biological membranes

Answer 1

phospholipids

Question 2

important component in the biological membranes of animal cells

Answer 2

Sphingolipids

Question 3

p.5

Answer 3

yes

Question 4

Components of biological membranes

Answer 4

1. Phospholipid bilayer
2. Interior protein network
3. Cell-­surface markers
4. Transmembrane proteins

Question 5

Provides selectively permeable barrier and a matrix for proteins

Answer 5

Phospholipid bilayer

Question 6

proteins located on the inside of the cell that are associated with the membrane, also called peripheral membrane proteins. Generally used to reinforce the membrane’s shape.

Answer 6

Interior protein network

Question 7

proteins that are either embedded in or span the lipid bilayer. They are able to move around just as the lipids do. These can be responsible for many functions
such as transport of nutrients or cell to cell signaling.

Answer 7

Transmembrane proteins

Question 8

Transporters

Answer 8

proteins that will only let a specific molecule into or out of the cell.Can be channels or carriers

Question 9

these proteins bind to molecules on the outside of the cell (such as hormones), and transmit the signal to the inside of the cell.

Answer 9

Cell surface receptors

Question 10

Proteins and glycoproteins help identify the cell within the body.

Answer 10

Cell­‐surface identity marker

Question 11

Cell to cell adhesion molecules

Answer 11

Proteins can be used by cells to attach to one another. These linkages can be short lived or quite strong

Question 12

Attachment to cytoskeleton

Answer 12

Cell to cell adhesion proteins are often also linked to the cytoskeleton of the cell as well.

Question 13

The interactions of the phospholipids and proteins within the membrane are quite weak, allowing them to move freely if unanchored to the cytoskeleton

Answer 13

fluid mosaic model

Question 14

more ________, the more rigid the membrane, but a more rigid membrane is less delicate than a ____ one

Answer 14

cholesterol, fluid

Question 15

Typically, cholesterol makes up about ___ of the molecules found in every cell membrane, because it is small, it only accounts for ___ of the weight

Answer 15

50%, 20%

Question 16

6 function of the membrane proteins

Answer 16

Transporters
Cell surface receptors
Cell­‐surface identity marker
Cell to cell adhesion molecules
Attachment to cytoskeleton
enzymatic