Chapter 1: Compartments

Question 1

What is the structure that defines each cell’s boundary?

Answer 1

plasma membrane

Question 2

What is the principal function of membranes?

Answer 2

to act as a barrier to diffusion of most water-soluble molecules

Question 3

The _________ _________ acts as scaffolding for certain proteins.

Answer 3

plasma membrane

Question 4

BE ABLE TO IDENTIFY THE ORGANELLES!

Answer 4

..

Question 5

What are the 2 components that all cellular membranes have?

Answer 5

a bilayer of polar lipid molecules and associated proteins

Question 6

DEFINITION: general permeability barrier, because most water-soluble (polar) molecules cannot readily traverse its nonpolar interior.

Answer 6

lipid bilayer
-hydrophilic, polar head
-hydrophobic, non-polar tail

Question 7

What 3 plant membranes have an inner and outer membrane?

Answer 7

nuclear envelope, chloroplast envelope, mitochondria

Question 8

All basic types of cell membranes are _____________.

Answer 8

inherited

Question 9

What are the 3 membrane inheritance rules?

Answer 9

1. Daughter cells inherit a complete set of membrane types from their mother.
2. Each potential mother cell maintains a complete set of membranes.
3. New membranes arise by growth and fission of existing membranes.

Question 10

The _____________ nature of membrane lipids allows for the spontaneous assembly of bilayers.

Answer 10

amphipathic

Question 11

In reference to the size of their hydrophilic heads, what size heads do sterols have?

Answer 11

small

Question 12

What are the 5 ways a phospholipid can move in the plane of the membrane/through the bilayer?

Answer 12

1. Lateral diffusion
2. Bobbing
3. Flexion
4. Rotation
5. Flip-flop

Question 13

Phospholipids move __________ in the plane of the membrane, but very __________ from one side of the bilayer to the other.

Answer 13

rapidly; slowly

Question 14

What is the name for the phospholipid translator that flips a phospholipid from one side of the bilayer to the other?

Answer 14

flippase

Question 15

Cells optimize the __________ of their membrane by controlling lipid composition.

Answer 15

fluidity

Question 16

What are two things that affect the temperature of melting of some phospholipids?

Answer 16

1. fatty acid chain length
2. double bonds

Question 17

High or Low Temp?
Long fatty acid chain
No double bond

Answer 17

high temp

Question 18

High or Low Temp?
Short fatty acid chain
Double bond

Answer 18

low temp

Question 19

Membrane proteins associate with __________ __________ in many different ways.

Answer 19

lipid bilayers

Question 20

The __________-_________ membrane model predicts structural and dynamic properties of cell membranes.

Answer 20

fluid-mosaic

Question 21

_________ ________________ leads to characteristic changes in plasma membrane lipid composition.

Answer 21

cold acclimation

Question 22

What is another name for the Hechtian strands that connect the protoplasts to the cell wall in the plasma membrane?

Answer 22

arrowheads

Question 23

The endomembrane system forms a ______________ network, the organizations of which changes during the cell cycle development.

Answer 23

dynamic

Question 24

The classical literature distinguishes 3 types of ER membranes: What are they?

Answer 24

1. rough ER
2. smooth ER
3. nuclear envelope

Question 25

______ bodies off a smooth ER membrane; _______ bodies that bud from specialized rough ER

Answer 25

oil; protein

Question 26

______________ ____________ mediate the transfer of newly synthesized secretory/storage/membrane proteins from the ER to the Golgi apparatus.

Answer 26

transport vesicles

Question 27

_____ ________________ _____________ appear to mediate non-vesicular lipid transport between the ER and other membrane systems.

Answer 27

ER attachment domains

Question 28

Plant golgi apparatus consists of dispersed golgi stack-golgi associated TGN (trans-golgi networks) units that exhibit a ____________ ______________ organization.

Answer 28

polar cisternal

Question 29

The Golgi scaffold/matrix originates on ___________ buds and mediates ER-to-Golgi _______ vesicle transport.

Answer 29

COPII

Question 30

The _________-most Golgi cistern give rise to TGN cisternae that sort and package Golgi products.

Answer 30

trans

Question 31

The Golgi apparatus is a ________________ factory.

Answer 31

carbohydrate

Question 32

DEFINITION: secretory vesicles derived from the TGN fuse with the plasma membrane, releasing their contents into the extracellular space.

Answer 32

exocytosis

Question 33

DEFINITION: a process by which cells absorb external material by engulfing it with the cell membrane.

Answer 33

endocytosis

Question 34

In the process of excess plasma membrane molecules being returned to the cytoplasm, endocytosis is mediated by ___________-_________ _______________ (_____) that contain membrane proteins and lipids.

Answer 34

clathrin-coated vesicles (CCVs)