Bio 141 Notes (2/18/14) Flashcards Preview

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Flashcards in Bio 141 Notes (2/18/14) Deck (23):
1

Membranes have

phospholipid bilayers

2

Fluid Mosaic Model

moves around up of many different things

3

Selective Permeability

most molecules cannot cross the membrane without help

4

Permeable

soak able, to get in, allow something across membrane

5

Membranes are often called

semi-permeable

6

Diffusion

molecules from areas of higher concentration to areas of lower concentration

7

Concentration

Number of molecules per volume

8

Concentration Gradient

Difference in concentration between two sides of membrane

9

Solute

Molecule that is dissolved
Salt

10

Solvent

Liquid that dissolves
Water

11

Dissolve in a

Solvent

12

Osmosis

diffusion of water across a membrane

13

Tonicity

hypertonic, hypotonic, isotonic

14

Hypertonic

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

15

Hypotonic

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

16

Isotonic

Equal
Normal

17

Concentration Gradient can affect cells...

survival

18

Passive Transport

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

19

Facilitated Diffusion

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

20

Gate Channels

opens in response to stimulus
Allosteric

21

Ligans

chemical signals that bind to proteins

22

Aquapoerins

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

23

Active Transport

requires energy (usually ATP) to more molecules against concentration gradient
- against gradient
-requires energy
- often named 'pump' instead of 'channel'