Ch3 Membranes

Question 1

Fluid Mosaic Model

Answer 1

Used to model how biomolecules are combined to form a structure (like cell membrane)

Question 2

3 components of Biomembrane
Which is the main

Answer 2

1. Phospholipid bilayer (MAIN)
2. Proteins
3. Carbohydrates

Question 3

Each membrane has

Answer 3

A unique composition of lipids and proteins suited for its functions

Question 4

Glycoproteins and glycolipids

Answer 4

Sugars linked to proteins and sugars linked to phospholipids on the outside of the membrane

Question 5

Membrane is fluid due to

Answer 5

Kinetic/thermal energy that causes motion in the phospholipids

Question 6

Cholesterol

Answer 6

Rigid molecule
Integrates itself in the phospholipid bilayer
Hydrophobic-Interacts w tails

Question 7

Membrane fluidity increases as Cholesterol

Answer 7

Cholesterol decreases
Less rigidity and structure

Question 8

Membrane fluidity increases as unsaturated fatty acids

Answer 8

Increase.
Cause the tails to be bent, and allows for more fluidity

Question 9

Membrane fluidity increases as temperature

Answer 9

Increases
More energy more movement more fluidity

Question 10

3 kinds of membrane proteins

Answer 10

1.Integral Proteins
2.Peripheral Membrane Proteins
3.Glycoproteins

Question 11

Integral proteins

Answer 11

Embedded in the membrane. Amphipathic
Can be in just 1 side or go all the way through

Question 12

Transmembrane protein

Answer 12

When a integral protein goes all the way through the membrane

Question 13

Peripheral membrane protein

Answer 13

Loosely bound to inside of membrane
Often bound to integral membrane proteins
Helps give structure to the cell

Question 14

Glycoproteins

Answer 14

Proteins with carbohydrates covalently bonded

Question 15

Biomembranes are

Answer 15

Asymmetrical

Question 16

6 functions of MP

Answer 16

1.transport
2.enzymatic activity
3.signal transduction
4.cell-cell recognition
5.intercellar joining
6.Attatchment to cytoskeleton+extracellular matrix

Question 17

Signal transduction

Answer 17

Protein acts as a receptor. Signal molecule binds and relays message to inside the cell.

Question 18

Cell-Cell recognition

Answer 18

Glycoproteins/lipids act as molecular markers for the immune system
(Tcells)

Question 19

Intracellular joining

Answer 19

Physical linking of the plasma membrane of adjacent cells

Question 20

Attatchment to cytoskeleton and extracellular matrix serves

Answer 20

Many different functions including cell shape

Question 21

Permeable

Answer 21

Substance that can pass

Question 22

Impermeable

Answer 22

Substance that can not pass

Question 23

Permeability is controlled

Answer 23

By the opening and closing of specific channels

Question 24

What 2 factors influence permeability

Answer 24

1. Solubility of molecule in lipids
   Lipid soluble-Pass Freely
2. Size of the molecule Smaller=more permeable

Question 25

Lipid soluble molecules are

Answer 25

Hydrophobic Non polar or uncharged Pass freely through membrane

Question 26

Lipid insoluble molecules

Answer 26

Hydrophillic Polar or charged Do not pass freely through membrane

Question 27

Passive transport

Answer 27

High to low energy/conc Favored by entropy/can be spontaneous No energy is required

Question 28

2 kinds of passive transport (One has 2 names)

Answer 28

Simple diffusion Carrier mediated/Facilitated diffusion

Question 29

2 kinds of Facilitated diffusion Aka

Answer 29

Channel proteins- Provides Hydrophillic pathways to allow water/small ions to pass freely Carrier Proteins- (oyster) undergo subtle changes in protein conformation/shape -allows translocation of specific molecule

Question 30

Simple diffusion Occurs until

Answer 30

Molecules go from high to low conc Until equilibrium is reached Movement still occurs but equally

Question 31

Large molecules diffuse

Answer 31

Slower than small ones

Question 32

Diffusion can only occur if

Answer 32

The membrane is PERMEABLE to the molecule

Question 33

Hydrophobics can diffuse

Answer 33

Through the membrane directly

Question 34

Hydrophilics must

Answer 34

Use other channels to cross the membrane

Question 35

Osmosis

Answer 35

Diffusion of water across membranes

Question 36

Most membranes are freely permeable to

Answer 36

Water

Question 37

The concentration of water and concentration of solute

Answer 37

Are inversely proportional. As one increase the other decreases.

Question 38

Tonicity Predicts the

Answer 38

Used to describe the solute in a solution relative to the solute in a typical cell. Predicts the magnitude + direction of osmosis

Question 39

Isotonic

Answer 39

Equal amount of solute inside and outside the cell

Question 40

Hypertonic

Answer 40

Concentration of solute is greater outside the cell than inside the cell. Cause cell to be shriveled

Question 41

Hypotonic

Answer 41

Concentration of solute inside the cell is greater than the concentration outside of the cell Causes cell to be lysed/burst open

Question 42

Terms for tonicity for plant cells

Answer 42

Isotonic Flaccid Hyper- Plasmolyzed Hypo- Turgid

Question 43

Primary active transport Ex?

Answer 43

Directly used energy from an ATP molecule Ex. Protein pumps/ Sodium Potassium pump ATPase

Question 44

How does the sodium potassium pump work For every 1 ATP molecule,

Answer 44

1) In the cytoplasm, low NA high K. 3 NA and ATP bind. 2) ATP hydrolizes. Phosphate attaches to protein. 3. Protein configuration changes. Low affinity for NA. They are released 4. Protein now has high K affinity. 2 Ks from outside bind. Phosphate falls off 5. Pump returns to original shape. 6.2 Ks are released Cycle continues. 3 NA 2 K

Question 45

Membrane potential

Answer 45

Difference in electrical potential between interior and exterior of membrane. Inside- negative Outside- positive

Question 46

A protein pump is

Answer 46

Active transport

Question 47

Secondary active transport

Answer 47

Uses STORED energy from HC, so that when a driving ion like H goes from HC-LC, that energy is used to drive a 2nd molecule against its gradient

Question 48

Secondary active transport is aka

Answer 48

Cotransport

Question 49

Small, hydrophobic molecules use ____ while large Hydrophillic molecules and ions use ____

Answer 49

Simple diffusion Facilitated diffusion

Question 50

MACRO molecules move across the membrane in 2 ways

Answer 50

Membrane bound vessels Exocytosis- molecules moving out of the cell Endocytosis- molecules moving into the cell

Question 51

3 kinds of endocytosis

Answer 51

Phagocytosis Pinocytosis Receptor-Mediated Endocytosis

Question 52

Phagocytosis Some or all cells

Answer 52

LARGE molecules brought into the cell “Cell eating” Some cells

Question 53

Pinocytosis Some or all cells

Answer 53

Small molecules brought into the cell “Cell drinking” ALL cells

Question 54

Receptor mediated endocytosis

Answer 54

Selectively bringing LARGE molecules into the cell. The cell membrane become the exterior of the vessel after a canyon is formed The interior is called the lumen

Question 55

Hat is the job of the bio membrane

Answer 55

The separate compartments