Transfer of things

Question 1

Why is the fluid mosaic model called that?

Answer 1

Because of the proteins scattered throughout the plasma membrane

Question 2

Do phospholipids arrange themselves in a bilayer spontaneously?

Answer 2

yes

Question 3

What are the types of lipids in a plasma membrane?

Answer 3

phospholipids
glycolipids
cholesterol

Question 4

What is the difference between glycolipids and phospholipids?

Answer 4

Glycolipids have a variety of sugars formed together to form a carbohydrate chain instead of a hydrophilic head

Question 5

What reduces the permeability of the membrane to most biological molecules?

Answer 5

cholesterol

Question 6

What kind are the proteins in a membrane ?

Answer 6

peripheral proteins or integral proteins

Question 7

Where is a peripheral protein located?

Answer 7

Inner or outer layer of phospholipid bilayer

Question 8

Where is an integral protein located

Answer 8

embedded in whole phospholipid bilayer

Question 9

What one has a hydrophilic head and hydrophobic body: peripheral protein or integral protein?

Answer 9

integral

Question 10

What kind of protein are many integral proteins

Answer 10

glycoproteins

Question 11

What do glycoproteins have?

Answer 11

Attached carbohydrate chain that projects externally

Question 12

Is the plasma membrane symmetrical?

Answer 12

no

Question 13

Where to the chains of glycolipids and proteins occur and attach

Answer 13

occur on outside surface of cytofilaments

attach on outside surfaces

Question 14

At room temperature what consistency does the phospholipid bilayer have?

Answer 14

like olive oil

Question 15

How does the phospholipid molecule move?

Answer 15

Hydrocarbon tails wiggle

Question 16

Are proteins free to drift in fluid bilayer?

Answer 16

some are

others are held in place by cytoskeletal filaments

Question 17

What determine a membranes specific function?

Answer 17

integral proteins

Question 18

How do channel proteins transport something?

Answer 18

Through it

Question 19

How does a carrier protein transport something?

Answer 19

Combines with a substance to help it move across

Question 20

How do receptor proteins transport things?

Answer 20

Has specific shape that allows it to bond with a specific molecule

Question 21

What do enzymatic proteins do?

Answer 21

Carry out metabolic reactions directly

Question 22

What do peripheral proteins often have a role in?

Answer 22

Structural role

They help stabilize the shape of the plasma membrane

Question 23

What does cholesterol control

Answer 23

fluidity

act to stiffen the membrane

Question 24

What do receptor proteins do?

Answer 24

bind substances in the environment and trigger cell responses

Question 25

What direction on the concentration gradient odes passive transport move?

Answer 25

High to low

Question 26

What drives passive mechanisms

Answer 26

random kinetic energy

Question 27

What kind of transport if diffusion an example of

Answer 27

passive transport

Question 28

What does active transfer require?

Answer 28

carrier protein

Question 29

How does active transport move cell products?

Answer 29

Through vesicle formation

Question 30

What Is exocytosis?

Answer 30

Vesicle mediated transport out of the cell

Question 31

What is endocytosis?

Answer 31

Vesicle mediated transport into the cell

Question 32

What is pinocytosis?

Answer 32

Cell drinking

Question 33

What is phagocytosis?

Answer 33

cell eating

Question 34

What is diffusion?

Answer 34

Movement of molecules from and area of high concentration to an area of low concentration

Question 35

What can diffuse freely across cell membrane?

Answer 35

lipid soluble molecules, gases, and some water soluble molecules

Question 36

What is osmosis?

Answer 36

Diffusion of water across a semi permeable membrane

Question 37

What is and what causes osmotic pressure?

Answer 37

Force that causes water to move in a direction | due to number of non-diffusible particles in solutions

Question 38

What happens in hypotonic solutions?

Answer 38

cell swells and bursts

Question 39

What happens in hypertonic solutions?

Answer 39

cell shrinks

Question 40

What happens in isotonic solutions?

Answer 40

no change

Question 41

What is receptor-mediated?

Answer 41

Specific kind of pinocytosis which occurs in response to receptor stimulation

Question 42

Can macromolecules diffuse across the plasma membrane?

Answer 42

no, too big

Question 43

Can ions and charged molecules diffuse across membrane?

Answer 43

no, can't enter the hydrophobic phase of the lipid bilayer

Question 44

Can non-charged molecules (oxygen and alcohols) pass through the membrane?

Answer 44

yes are lipid soluble can slip in between the hydrophobic heads of the phospholipids

Question 45

Can small polar molecules (CO2 H2O) cross the membrane?

Answer 45

yes, follow the concentration gradients

Question 46

Are carrier proteins specific to the substance they carry across?

Answer 46

yes

Question 47

How does facilitated transport move things ?

Answer 47

from high on the concentration gradient to low

Question 48

What are the passive methods of transport?

Answer 48

diffusion | facilitated transport

Question 49

What are the active ways to cross a membrane?

Answer 49

include active transport, endocytosis, exocytosis

Question 50

What is tonicity?

Answer 50

Strength of a solution in relationship to osmosis

Question 51

What is lysis?

Answer 51

term refers to disrupted cells

Question 52

What is hemolysis?

Answer 52

rupture of RBCs

Question 53

What is turgor pressure?

Answer 53

created by swelling of plant cell in a hypotonic solution

Question 54

What is turgor pressor important to?

Answer 54

plant's erect position

Question 55

What happens when a plant is placed in a hypotonic solution?

Answer 55

cytoplasm expands

Question 56

What is crenation?

Answer 56

Shrinkage of cells when surrounding solution is hypertonic to cytoplasm

Question 57

What is plasmolysis?

Answer 57

shrinking of cytoplasm due to osmosis

Question 58

What explains the passage of amino acids and glucose (they are not lipid soluble) across membrane?

Answer 58

facilitated transport

Question 59

What are proteins that are involved in active transport often called?

Answer 59

pumps

Question 60

What do pumps do?

Answer 60

use energy to move a substance against concentration gradient

Question 61

What does the sodium potassium pump do?

Answer 61

Moves sodium ions outside of cell and potassium ions inside the cell

Question 62

What cells is the sodium potassium pump exceptionally active?

Answer 62

nerve and muscle cells

Question 63

What allows the carrier to combine alternately with sodium and potassium in a sodium potassium pump?

Answer 63

change in carrier shape

Question 64

What is diffused when NA+ is pumped across the membrane?

Answer 64

Cl-

Question 65

Factors that effect rate of diffusion?

Answer 65

``` size shape concentration charge lipid solubility temperature ```