Exam 3

the process of particles moving through a solution from an area with a higher # of particles to an area of a lower # of particles

a gradient of electrochemical potential, usually for an ion that can move across a membrane.

the differences in ion concentration of the intracellular and extracellular fluids (potassium-sodium pump)

patch clamp technique

• Technique used to record electrical currents through individual ion channels in cells.

• Involves placing a glass pipette on the cell membrane and applying suction to form a tight seal

• Allows for precise measurement of ion flow and can be used to study the effects of drugs on ion channels

almost never used

useful for recording ion channels in a cell

inside of cell is out in both

this is usually the valuable patch for recording a single ion channel after drug

starting mem. potential of ~ -60mV → then record current through all of the channcels

drug is really lipophilic and gets inside the cell well → inside out patch

the sodium-potassium pump

K+

Cl-, Na+, Ca++

• helps maintain equilibrium and membrane potential in cells

• keep K+ high inside, this is what cells need at rest

• why & what

  • maintain resting membrane potential

  • 3 Na+ in → out

  • ATP hydrolysis → phosphorylation of pump

  • 2 K+ out → in

whole cell patch clamping

takes an electrical change in the membrane potential to open

molecule acts as a key to open the door

physically pull door open

helps scientists figure out what the membrane potential of any membrane is

transport a single species of substrate across a cell membrane

proteins that simultaneously transport two molecules across a membrane in the same direction

transport of two or more different molecules or ions across a phospholipid membrane

2 NADH

2 H+

0 CO2

2 net ATP

0 GTP

0 FADH2

2 pyruvates

2 NADH

2 H+

2 CO2

0 net ATP

0 GTP

0 FADH2

2 acetyle CoA

6 NADH

6 H+

4 CO2

0 net ATP

2 GTP

2 FADH2

2 HS-CoA

• He had a single-base pair mutation that resulted in a lack of pyruvate dehydrogenase

• Without this enzyme, his cells couldn't convert pyruvate into acetyl CoA, instead making more lactase, leading to lactic acid buildup

• without pyruvate dehydrogenase, his cells couldn't continue with aerobic metabolism

• without the enzyme, acetyl CoA couldn't be made, meaning the step between glycolysis and CAC didn't happen, and neither did the CAC and oxidative phosphorylation, meaning no ATP production

• He was in pain due to the lactic acid buildup in his cells (lactate acidosis)

• The acidosis lead to hyperventilation, muscle pain & weakness, and abdominal pain & nausea

• a high-fat, low-carbohydrate diet might have helped Patrick because fats skip through the portion of glycolysis that Patrick's cells couldn't undergo (they jumped directly to acetyl CoA, instead of having to go through glycolysis and be turned from pyruvate to acetyl CoA).

• use dichloroacetate (DCA), which blocks the enzyme that converts PDH from active to inactive forms.

  • This says that Patrick had some of the enzyme and doctors would have kept what he had active - the "make the most of what you've got" strategy

action potential zips down motor neuron

at the terminal end of the axon, voltage gate Ca++ ion channels open

the influx of calcium makes vesicles dock & dump out neurotransmitter → acetylcholine (Ach)

Ach is received by receptors on muscle cell membrane AchR

Whoosh Na+ rushes into the muscle cell through the nAchR channels

zip action potential zooms down the muscle cell membrane down into t-tubules

this makes ryanodine receptors on the sarcoplasmicreticulum (SR) organelle open

Ca++ comes rushong out of the SR

Ca++ binds to troponin

making tropomyosin move out of the way of myosin/actin cross bridging sites

ATP hydrolysis on myosin heads allows cross bridging & power-stroke for sliding filament contractions

• Christmas Island rat extinct, bring back?

• CRISPR edit the Norway brown rat to make it “Christmasy”

• 95% identity b/w the two rats

• identity → identical DNA bases

• homology → about bases but more about functional products

• developed “cyborg” cells

• infused artificial polymers into bacteria → what does this mean?

• bacteria with a hydrogel inside still “alive” but not replicating

• human collin interacting?

• this enzyme can postpone aging → p53 was used as a marker of aging

• b/c it was affecting transcription → Δ histone meth

• anti-aging from weeds?

• cocklebure plant has materials that help with wound healing and wrinkle reduction

• kidney stones (calcium oxalate)

• can lemon juice actually work?

• lemon extract nanoparticles ; soften stones but didn’t stop

• endometriosis antibody therapy

• interleukin-8

• tested in primates (1x/month injections)