Chapter 5 Pt 2

Question 1

Membrane Structure

Answer 1

o Phospholipd bilaye
o Fluid mosaic model
-Mosaic of proteins floats in or on the fluid lipid bilayer like boats on a pond

Question 2

4 components of membranes

Answer 2

• Phospholipid bilayer
• Transmembrane proteins
• Interior protein between
• Cell surface markers

Question 3

Phospholipid bilayer

Answer 3

o Fluid
o Hydrogen bonding of water holds the 2 layers together
o Individual phospholipids and unanchored proteins can move through membrane

Question 4

Influences of fluidity

Answer 4

 Saturated fatty acids make the membrane less fluid than unsaturated fatty acids
 Warm temperatures make the membrane more fluid than cold temperatures

Question 5

As temperature cool, membranes switch from a _____

Answer 5

fluid state to a solid state

Question 6

Membranes must be _____ to work properly

Answer 6

Fluid

Question 7

Membranes rich in _______ ____ ______ are more fluid

Answer 7

Unsaturated fatty acids

Question 8

Cholesterol

Answer 8

Steroid alcohol added to membranes

Question 9

o Warm temperature, cholesterol ______ movement of phospholipids

Answer 9

restrains

Question 10

At cool temperatures cholesterol maintains fluidity by preventing _____ _______

Answer 10

tight packing

Question 11

Peripheral proteins

Answer 11

Bound to the surface of the membrane

Question 12

Integral proteins

Answer 12

Penetrate the hydrophobic core

Question 13

Membrane proteins functions

Answer 13

	Transporters
	Enzymes
	Cell-surface receptors
	Cell-surface identity markers
	Cell-to-cell adhesion proteins
	Attachments to the cytoskeleton

Question 14

Membrane proteins Structure relates to _____

Answer 14

function

Question 15

Anchoring molecules

Answer 15

-Modified lipids

=Integral membrane proteins

Question 16

Modified lipids

Answer 16

 Non polar region insert to the internal portion of the lipid bilayer
 Chemical bonding domains linked directlhy to proteins

Question 17

o Integral membrane proteins

Answer 17

-Span the lipid bilayer
        •	 Non polar interior
        •	Polar exterior
-Transmembrane domain
       •	Spans the lipid bilayer
       •	Hydrophobic amino acids arranged in a-helixs

Question 18

Pores

Answer 18

o Extensive non polar can create a pore through the membrane

o Cylinder of B sheets in the protein secondary structure called a B-barrel

Question 19

Passive transport

Answer 19

o Transport is movement through membrane

-No energy needed

Question 20

o Non-polar molecules will move until

Answer 20

concentration is equal on both sides

Question 21

o Limited permeability to

Answer 21

small polar molecules

Question 22

o Very limited to

Answer 22

larger polar molecule and ions

Question 23

 Pass through membrane rapidly

Answer 23

Hydrophobic

Question 24

Do not cross easily

Answer 24

Hydrophillic

Question 25

Facilitated Diffusion

Answer 25

o Molecules that can’t cross easily move through proteins

o Move from higher to lower concentration

Question 26

• Channel proteins

Answer 26

o Hydrophilic channel when open

Question 27

• Carrier proteins

Answer 27

o Bind to molecules they assist
o Transport ions and other solute
o Require concentration difference across the membrane

Question 28

o 3 conditions determine direction (carrier proteins)

Answer 28

 Relative conventration on either side of membrane
 Voltage difference across membrane
 Gated channels

Question 29

• Osmosis

Answer 29

o Cytoplams is aqueous
-Water is solvent
-Dissolved substance are solutes
o Net diffusion of water across a membrane toward higher solute concentration

Question 30

o Hypertonic

Answer 30

 solution has a higher solute concentration

Question 31

o Hypotonic

Answer 31

 Solution has a lower solute concentration
 Gains water
 Cause it to swell

Question 32

o Iso tonic

Answer 32

 Same osmotic concentration

Question 33

• Plasmolysis

Answer 33

o Membrane pull away from cell wall

 Plant wilt

Question 34

• Active transport

Answer 34

o Requires energy
o ATP
o Moves from low to high concentration
o Selective carrier proteins

Question 35

o Uniporters

Answer 35

 One molecule

 Same direction

Question 36

o Symporters

Answer 36

 Move two molecules

 Same direction

Question 37

o Anitporters

Answer 37

 Move two molecules in opposite directions

Question 38

• Sodium-potassium pump

Answer 38

o Direct use of ATP for active transport

o Antiporter to move 3Na+ out of the cell and 2K+ into the cell

Question 39

• Coupled transport

Answer 39

o Uses ATP indirectly
o Uses the energy released when a molecule moves by diffusion to supply energy to active transport of different molecule
o Symport is used

Question 40

o Endocytosis

Answer 40

• Movement into the cells

* Requires energy

Question 41

 Phagocytosis

Answer 41

• Takes in particular matter

Question 42

 Pinocytosis

Answer 42

• Cell takes in only fluid

Question 43

 Receptor mediated endocytosis

Answer 43

• Specific molecules are taken in after they bind to a receptor

Question 44

o Exocytosis

Answer 44

 Movement out of cell

 Requires energy