Question

Growth hormone and insulin are protein hormones that regulate carbohydrate metabolism by hepatocytes (liver cells) through the activation of intracellular signaling pathways. Researchers investigated whether the two hormones trigger the same or different intracellular signaling pathways in hepatocytes. The researchers added either growth hormone or insulin to parallel cultures of hepatocytes. At several time points after the hormone addition, they purified total intracellular protein from the cells and quantified the level of the phosphorylated forms of two proteins involved in two different signaling pathways (Figure 1, A and B)

(c) describe the hormone and signaling proteins combination that produce the greatest and most prolonged response. For the phosphorylated STAT5 response that reached 100% at 10 minutes in Figure 1A, calculate the rate of decrease (percent decrease per minute) in the detected level of phosphorylated STAT5 from 10 to 30 minutes.

Answer 1

Rate of decrease = 3.25 levels/min

Step-by-step explanation:

the hormone and signaling proteins combination that produce the greatest and most prolonged response as seen in the graph is INSULIN and PROTEIN KINASE. The protein kinase B level gets up to 100 after 30minutes and as well as insulin gets added while the level remained to near 80 even after 240minutes.

The STAT 5 level at the 10th minutes = 100

The level of STAT 5 at 30th minute = 35

From 10 to 30 minutes, the level of STAT 5 = 100 – 35

From 10 to 30 minutes, the level of STAT 5 = 65

Duration = 30 – 10 minutes

Duration = 20 minutes

Rate of decrease = 65/20

Rate of decrease = 3.25 levels/min