2.8.20101. Chloride has a negative charge

a. But Endothermic (should be exothermic because engative) b. Concentration and chargec. Formula delta gmd. Takes into account charge on ion and membranee. –Moving more negative ions into the cell from the outside (or pumping

positive ions out) increases Vm , and so requires energy, membrane difference across the membrane

2. Sodium across membranea. More on outside and positive chargeb. deltaGc and delta Gm

i. exothermic reaction to move sodium across membrane3. Facilitated diffusion

a. Some sort of protein that aids in movement of molecules along concentration gradient.

b. Usually larger molecules or charged ionsc. Carrier proteins bring in molecules along concentration gradient

i. Act like switched1. Undergo conformational change

a. Cytosolic state etcii. Uniports

1. Specific carriers that may carry only oneiii. Symport

1. Exothermic movement of another to drive the movement of another

iv. Antiport1. Exothermic movement of another to drive the movement of

anotherv. Exhibit saturation kenetics

1. For facilitated diffusion, the rate of movement across the membrane, V, verusus the concentration of whatever is being moved across the membrane is going to saturate as binding sites are used up

2. Competitive inhibitiond. Example: Glucose transporter, GLUT-1

i. Trafficking is dependent on concetration of glucose on either side of membrane

ii. Glucose is converted by hexokinase to glucose-6-phosphate1. Keep glucose concentrations low

iii. Glucose interacts with binding site on transporter1. T1 state, cytosolic

2. Binds, changes conformation and faces inside, T2 state, lower affinity for glucose and releases

3. conformation change, T1e. Coupled Carriers RBCs

i. Antiport1. RBC takes in CO2 and releases O22. When RBC is in capillaries of blood tissue, CO2 is high O2 is

low on outside and they can move through membrane by diffusion

3. RBC can convert CO2 to bicarbonate by carbonic anhydrasea. Carried to lungs and released when converted back

to CO2b. Caronate binds to antiporter and is used to bring Cl-

into the cell.c. When moved to lungs, reversed situation, O2 is high

and CO2 is low, so RBC will pick up oxygen, bound by hemoglobin and CO2 is released. Cl- is taken out and bicarbonate is brought back in.

f. Kinetics of diffusioni. Hyperbolic is characteristic of saturation points

g. Coupled Diffusion – channel proteinsi. Selective

ii. Selectivity filters1. Charged amino acids that specifically bind to ions that will

be moved through that pore after waters of hydration havea. Na+ movement though ion channel and K+

i. w/in both channels, there are regions that have reactivity filters for Na and K

ii. Sodium in, K out1. Water is stripped around sodium,

making it a very small ion, and as it moves through filter, it binds temporarily, pushed out, and K enters cytoplasm and binds up by water

iii. Opened and closed states by different mechanisms1. Voltage2. Ligand that binds to channel3. Mechanically gated channels

a. Stretching of membrane opens the channel4. Important for maintaining membrane potential5. Allow for electrical signaling6. Important for maintain concentration gradients

iv. Aquaporin1. Allows rapid diffusion of water in a tissue with a lot of salts

v. Porins1. Move larger hydrophilic molecules through membrane

4. Active Transporta. Endothermic and requires energyb. Light may be requiredc. Movement against concentration or electrical gradient or a combinationd. Examplese. Direct or Indirect

i. Direct1. ATP hydrolyzation to move molecules across membrane2. stomac

ii. Indirect1. Energy released from one molecule moving down

concetration gradient to move another molecule up.2. Stomach3. Na coupled to movement of glucose

a. Sodium must bind for glucose to bind in that order.b. Polarized cells are created

f. Family of ATPasesi. P type

1. Hydrolyze ATP2. Na+/K+

a. 3:2b. Moved In:Moved Outc. Na comes in for action potentials in neuronsd. Indirect active transport

3. When cytoslic state, triggers phosphorylation4.

ii. V-type1. Used to pump H+ across membrane for pH maintenance

iii. F-type1. ATP synthases

iv. ABC-type1. Bind ATP2. ATP Binding Casettes

a. bind polypeptidesb. carry drugsc. tumor cells can extrude drugs that are used to help

regulate oncogenic behaviord. multidrug resistance transport protein

3. 2 bindigs sites in cell for ATP and when bound, undergoes conformational change, but in process, pore opens

a. lipid flipping when pore opensv. Maintain concentration gradients

vi. Maintain membrane potentialvii. Regulating osmolarity

5. Transcellular Transporta. Tight junctions

6. Light-Driven Pumpsa. Bacteriaorrhodopsin

i. Drive electron proton gradientb. Seen in eyes

7. Glycolysis Sections Startsa. Cellular Respiration

i. Must have a way to make energy in cellii. Catbolic and anabolic reactions

1. Catabolica. Breakdown of macromolecules to smaller, individual

components that yield energy2. Anabolic

iii. 36 ATP madeiv. Chemical source of energy

1. ATP or GTPv. Electrical Force

1. ETCvi. Final reaction

1. 1 glucose 36ATP + 6CO2 + 2GTP + 6H20