designed by pyeongsug kim ©2010 [email protected]@science-i.com supplemental...

Designed by Pyeongsug Kim ©2010 [email protected]

Supplemental instruction

Cells and Their EnvironmentsCells and Their Environments

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____________ random movement of molecules from region of high to low concentration.

Diffusion

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-block most solutes from diffusing-Hydrophilic solutes (can/cannot) pass through-Hydrophophic solutes (can/cannot) pass through

Why?Hydrophilic solutes do not mix with the hydrophobic phospholipids of the cell membrane.Hydrophobic will mix with the hydrophobic phospholipids of the cell membrane.

Plasma membranePlasma membrane

-Selectively permeable (semipermeable)-(non-polar / polar) molecules diffuse through cell membrane



1)

2)

3)

Simple diffusion (only hydrphobic)

By endocytosis and exocytosis

Through membrane transport proteins

How molecules can cross cell membranes?

e.g Steroid hormones, O2, CO2

Highly specific to transport only the solute



Bulk transport Bulk transport : Cells move large compounds across membrane with endo- and exocytosis.



______________- brings solute molecules into a cell by the membrane bending inward, followed by the bend pinching off from membrane -form a ______ inside the cell

Endocytosis

vesicle

_______________-brings solute molecules out of a cell by the molecules moving into a ________ in the cell inward followed by the vesicle fusing with the cell membrane

Exocytosis

vesicle



DownDown concentration gradient (HL)

ATP (required/no required) (Passive/Active)

Against Against concentration gradient (LH)

ATP (required/no required) (Passive/Active)



________________________: molecules too large and polar to diffuse across membrane are transported by proteins.

Carrier-mediated transport

________________-(passive/active) transport down concentration gradient w/carrier proteins.-ATP (required/no required)

Facilitated diffusion

______________: transport of molecules from (high/low) concentration to (high/low) concentration.Active transport

Na+/K+ pump Na+/K+ pump -ATP (required/no required)- ______ out and _____ in cell against gradients.3 Na+ 2 K+



Na+/K+ pumpNa+/K+ pump

Na+/K+ pump Na+/K+ pump -ATP (required/no required)- ______ out and _____ in cell against gradients.3 Na+ 2 K+



_________________ voltage across membrane due to only 1 ion whereelectrical and diffusion forces are equal and opposite.ie/ K+ =_______ , Na+ = _____

Equilibrium potential

-90mV 60mV

________________________-Not producing impulses,-Around _______ -K+ drives most of RMP because it is quite permeable.

Resting membrane potential (RMP)

-70mV

Cell membrane is more pearmeable ( K+ than Na+ / Na+ than K+) .


Secondary active transportSecondary active transport -ATP moves Na+ to create gradient, Na+ moves downhill to bring in another molecule.____________ = same direction as Na+._____________= opposite direction of Na+.Cotransport

Countertransport

Cotransport


QUESTION 2 (Cont’d)QUESTION 2 (Cont’d)

2-4. Determine what type of transport is. (e.g passive, active, 1o 2 o co- or counter transport…) in A, B, & C.

S: 0.5MS1: 0.3MS2: 0.8M

S: 0.3MS1: 0.6MS2: 0.5M

A B C


____________ random movement of molecules from region of high to low concentration.

Diffusion

___________ net diffusion of H2O across selectively permeable membrane.

Osmosis

Water diffuses until concentration is equal on both sides of membrane.

__________ : water channels to facilitate osmosis.Aquaporins

Less solute High soluteWater

_______________: force needed to stop osmosis. It is proportional tosolute concentration.Osmotic pressure


_________ effect of solution of osmotic water movement.Tonicity

___________ solutions with same osmotic pressure.___________solutions with higher osmotic pressure than cell that are osmotically active.___________ lower osmotic pressure.

IsotonicHypertonic

Hypotonic

Cells in hypotonic solution______= The bursting of a cellLysis

Cells in hypertonic solution________ = The crinkled shape of a cell that has lost waterCrenated


Common isotonic intravenous solutions used in hospitals:

- 0.9% Saline (NaCl) (“Normal saline”)- 5% Glucose (“5% dextrose”)- Ringer’s lactate


___________________ = 1 mole of solute dissolved in 1L of solution

___________________= 1 mole of solute dissolved in 1 kg H2O.

___________________= total molarity of a solutionEx/ 1.0m of NaCl = 2 Osm solution (NaCL dissociates into Na+ and Cl-)

1 molar solution (1.0M)

1 molal solution (1.0m)

Osmolarity (Osm)


QUESTION 3QUESTION 3Please, solve the problems without your note and textbook.

3-1. There are three type of solution regarding tonicity. What are they? What happen when cells are in each solution?

3-2. Where is most fluid in our body? The interstitial fluid comprises what percentage of the extracellular fluid?

3-3. What will the cell happen in the picture below?

A: 0.3 osm(penetrating)B: 0.8 osm

A: 0.3 osmB: 0.3 osmC: 0.7 osm


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