Lectures 13 & 14 Flashcards

1
Q

osmosis

A

diffusion of water molecules across a selective (semi-permeable) barrier
* high to low concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

selective (semi-permeable) barrier

A

a barrier that allows water molecules to pass through, but not most of the molecules dissolved in the water
ex. plasma membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How concentrated is water with no solutes?

A

100%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The concentration of water is determined by _____.

A

concentration of solutes in the water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

solutes

A

molecules that are dissolved in water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What happens to water concentration when you add solutes?

A

water concentration goes down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Solute potential

A

measure of the concentration of solutes dissolved in water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does adding solutes do to solute potential and H2O concentration?

A

lowers Ψs < 0
Lowers H2O concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the solute potential when a water has no solutes

A

0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

correlations between solute potential, solute concentration, and water concentration

A
  • solute potential and water concentration = direct
  • both inverse w/ solute concentration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

water moves from ___ solute potential to areas of ___ solute potential

A

higher, lower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

isotonic

A

Ψs inside and outside of a cell are equal
Water enters and leaves cell in equal amounts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

hypotonic

A

Water concentration is higher outside of the cell than inside
Water will diffuse into the cell → cell will swell → cell bursts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

hypertonic

A

Water concentration is higher inside the cell than inside
Water will diffuse out of the cell → cell will shrink → cell could dehydrate and die

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

brain capillaries

A

fine blood vessels that feed brain tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Blood-Brain-Barrier definition, problem, and solution

A

strict control of what can go out of the bloodstream into blood tissue (so toxins and bad things don’t go into brain tissue)
* Problem - when doctors need to introduce medicines into the brain b/c blood brain barrier keeps most medicines from entering the brain (no receptors and transporters to get them in)
* Solution - doctors inject a solute into the blood: now H2O concentration is higher inside the CWS than in the blood → water diffuses out of CWC into blood
- CWC shrink and create space between the cells so medicine can go through

15
Q

kinetic energy

A

energy of motion
Ex. heat, light, mechanical (wind, water)

16
Q

potential energy

A

stored energy
Ex. concentration gradient, chemical bonds

17
Q

first law of thermodynamics

A

Conservation Law:
Energy cannot be created or destroyed, can only change from one form to another
Total amount of energy in universe reaminds constant

18
Q

Second Law of thermodynamics
(definition of entropy and free energy)

A
  • No energy transfer is 100% efficient
  • Some energy is always lost (usually heat) and becomes unusable
  • Entropy (unusable energy) in universe is continuously increasing
  • Free energy (usable energy) in the universe is continuously decreasing
19
Q

free energy formula

A

G = H - TS
* H=enthalpy
*T=temp
*S=entropy

20
Q

enthalpy

A

total amount of energy (usable and unsable) contained in a molecule

21
Q

What determines the 2 types of reactions

A

change free energy

22
Q

-△G = exergonic

A

(products have less free energy than og reactants)
Free energy is released and can be used to do work
Could occur spontaneously: rxn has the potential to go forward without extra energy
Brick analogy: over time, a nice stack of bricks will fall over and decay

23
2 types of rxns
-△G = exergonic (products have less free energy than og reactants) +△G = endergonic (products have more free energy than og reactants)
24
+△G = endergonic
(products have more free energy than og reactants) Energy is absorbed (input of energy required) Never occur spontaneously: rxn won’t go forward without input of energy Brick analogy: over time, a nice stack of bricks won’t have more bricks added upon itself
25
Reaction coupling
Exergonic and endergonic rxns are coupled together Energy to drive endergonic (energy requiring) reactions comes from exergonic ( energy releasing reactions)
26
ATP
energy currency of cell
27
ATP Hydrolysis * exergonic or endogonic * reactants * products
exergonic rxn Reactants: high free energy ATP and H2O Products: lower free energy ADP + other products -△G (energy is released): energy is used to power endergonic rxns in a cell