Answer the following using the image below. a. In th 9) e top panel the membrane

Question

Answer the following using the image below. a. In th 9) e top panel the membrane potential is being manipulated experimentally. What is the name of this technique? (2 points) ere is an early inward current and a late outward current. Which ion is responsible for each of these currents? (2 points) How could you prove that this is true? (2 points) b. Th hy does the early current change in the panels on the right of the figure? Be sure to explain specifically why this is happening on a molecular basis.(4 points) c. W 75 50 25 +52 26 -50 -2 Time (ms)

Explanation / Answer

a. the technique is called patch clamp technique, particularly called as voltage clamp

b. Early inward current is due to entry of sodium (Na) ions across the cell membrane (polarisation). Late outward current is due to exit of potassium (K) ions across the cell membrane (depolarisation). This is proved by initially negative membrane potential by sodium (inward current) and positive membrane potential by potassium (outward current) lately in the image from left side to right side.

c. Early current changed by first increasing (due to entry of Na ion and polarisation of membrane) then decreases in magnitude as the depolarization increases by the exit of potassium ions and polarity is reversed (+ve).

Early current is inward (graph on 1-2 panel left side) because of the presence of normal external concentrations of Na. External removal or decrease or under equilibrium condition of Na results in initial inward current to become outward (graph on 3-5 extreme right side panel). Molecular basis for this is at the Na+ equilibrium potential there is no net flux of Na+ across the membrane, even if the membrane is highly permeable to Na+ hence early current has become outward and polarity changed to +ve, In the presence of excess sodium current again becames inward and polarity changed to -ve

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.