Question

1. Please describe the processes by which insulin (a protein hormone) is generated by β cells from the INS (insulin) gene. Please label any pictures you use.

2. Please describe (a.) how potential energy is created across a cell membrane (Resting Potential) and (b.) how this potential energy is released during an Action Potential.

3. ATP synthase, the final step of the Electron Transport Chain, creates a high-energy compound called _____ by taking a lower-energy compound called ____ and modifying it by __________________________.

4. list the 3 types of muscle tissue and describe or draw 2 anatomical features that would allow you to identify each.

Answer 1

1. Please describe the processes by which insulin (a protein hormone) is generated by β cells from the INS (insulin) gene. Please label any pictures you use.

Insulin secretion involves a sequence of events in β-cells that lead to fusion of secretory granules with the plasma membrane. Insulin is secreted primarily in response to glucose, while other nutrients such as free fatty acids and amino acids can augment glucose-induced insulin secretion.

The INS gene provides instructions for producing the hormone insulin, which is necessary for the control of glucose levels in the blood. Glucose is a simple sugar and the primary energy source for most cells in the body.

Fig: The mechanism of insulin released by β cells

2. (a.) how potential energy is created across a cell membrane (Resting Potential)

The resting membrane potential is a result of different concentrations inside and outside the cell. The difference in the number of positively charged potassium ions (K⁺) inside and outside the cell dominates the resting membrane potential

When the membrane is at rest, K+ ions accumulate inside the cell due to a net movement with the concentration gradient. The negative resting membrane potential is created and maintained by increasing the concentration of cations outside the cell (in the extracellular fluid) relative to inside the cell (in the cytoplasm). The negative charge within the cell is created by the cell membrane being more permeable to potassium ion movement than sodium ion movemen

2 (b.) how this potential energy is released during an Action Potential.

A neuron that emits an action potential, or nerve impulse, is often said to "fire". Action potentials are generated by special types of voltage-gated ion channels embedded in a cell's plasma membrane. These channels are shut when the membrane potential is near the (negative) resting potential of the cell, but they rapidly begin to open if the membrane potential increases to a precisely defined threshold voltage, depolarising the transmembrane potential.

When the channels open, they allow an inward flow of sodium ions, which changes the electrochemical gradient, which in turn produces a further rise in the membrane potential. This then causes more channels to open, producing a greater electric current across the cell membrane and so on.

3.ATP synthase, the final step of the Electron Transport Chain, creates a high-energy compound called _ Oxidative phosphorylation by taking a lower-energy compound called (NADH+H+) and FADH2 and modifying it by electron transport chain.

4. List the 3 types of muscle tissue and describe or draw 2 anatomical features that would allow you to identify each.

The 3 types of muscle tissue are cardiac, smooth, and skeletal muscle tissues .

Cardiac muscle cells are located in the walls of the heart, appear striated, and are under involuntary control.

Smooth muscle fibers are located in walls of hollow visceral organs, except the heart, appear spindle-shaped, and are also under involuntary control.

Skeletal muscle fibers occur in muscles which are attached to the skeleton. They are striated in appearance and are under voluntary control.