Bio 141 Notes (2/18/14)

Question 1

Membranes have

Answer 1

phospholipid bilayers

Question 2

Fluid Mosaic Model

Answer 2

moves around up of many different things

Question 3

Selective Permeability

Answer 3

most molecules cannot cross the membrane without help

Question 4

Permeable

Answer 4

soak able, to get in, allow something across membrane

Question 5

Membranes are often called

Answer 5

semi-permeable

Question 6

Diffusion

Answer 6

molecules from areas of higher concentration to areas of lower concentration

Question 7

Concentration

Answer 7

Number of molecules per volume

Question 8

Concentration Gradient

Answer 8

Difference in concentration between two sides of membrane

Question 9

Solute

Answer 9

Molecule that is dissolved

Salt

Question 10

Solvent

Answer 10

Liquid that dissolves

Water

Question 11

Dissolve in a

Answer 11

Solvent

Question 12

Osmosis

Answer 12

diffusion of water across a membrane

Question 13

Tonicity

Answer 13

hypertonic, hypotonic, isotonic

Question 14

Hypertonic

Answer 14

concentration is higher on the outside of the cell
High concentration of solute
Shrivels

Question 15

Hypotonic

Answer 15

Concentration is higher on the inside of the cell
Low concentration of solute
Lyses

Question 16

Isotonic

Answer 16

Equal

Normal

Question 17

Concentration Gradient can affect cells…

Answer 17

survival

Question 18

Passive Transport

Answer 18

solute movement with the concentration gradient
no energy needed
simple diffusion
facilitated diffusion

Question 19

Facilitated Diffusion

Answer 19

molecules allowed to cross the membrane via specific patterns
(protein is the bouncer)

Question 20

Gate Channels

Answer 20

opens in response to stimulus

Allosteric

Question 21

Ligans

Answer 21

chemical signals that bind to proteins

Question 22

Aquapoerins

Answer 22

allow water to diffuse across membranes
found in mammal kidney and plant root cells
(important for water absorption)

Question 23

Active Transport

Answer 23

requires energy (usually ATP) to more molecules against concentration gradient

• against gradient
• requires energy
• often named ‘pump’ instead of ‘channel’