Signal Transmission and Gene Expression

Which of the following physiological responses is primarily associated with the release of epinephrine?

• Decreased heart rate and increased relaxation

• Heightened alertness and increased heart rate

• Reduced sweating and lower blood pressure

• Slower metabolism and decreased energy

What are the two main categories of signal transmission based on the location of chemical movement?

• Endocrine and exocrine

• Autocrine and paracrine

• Intercellular and intracellular

• Synaptic and hormonal

How does epinephrine primarily increase the availability of glucose in the body, particularly from liver cells?

• By directly converting fats into glucose

• By activating phosphorylase, which breaks down glycogen into glucose

• By increasing the absorption of glucose from the digestive system

• By inhibiting the production of insulin

What is the immediate effect when epinephrine binds to its specific receptor on the cell membrane?

• The receptor is immediately degraded

• The cell membrane becomes impermeable to all substances

• The receptor changes shape, initiating an intracellular signaling cascade

• Epinephrine directly enters the cell nucleus

What is the immediate role of cyclic AMP (cAMP) in the signal transduction pathway that leads to glycogen breakdown?

• Directly breaking down glycogen into glucose.

• Activating the cell surface receptor.

• Activating protein kinase.

• Converting ATP into ADP.

What is the primary biological advantage of having multiple steps in a signal transduction pathway?

• It allows the cell to respond to a wider variety of external signals.

• It provides opportunities to amplify the initial signal, leading to a robust cellular response.

• It ensures that the signaling molecule can directly enter the cell's nucleus.

• It simplifies the cellular machinery required for signal processing.

In the context of gene expression initiated by an extracellular signal, what is the function of a transcription factor like CREB?

• It catalyzes the conversion of ATP to cAMP.

• It binds to DNA to regulate the transcription of specific genes.

• It acts as a structural component of the cell membrane.

• It directly breaks down complex carbohydrates into simple sugars.

Signal transduction pathways enable cells to achieve which of the following outcomes?

• Exclusive reliance on pre-existing enzymes for all cellular responses.

• The ability to directly transport large signaling molecules across the plasma membrane.

• A rapid and localized response without affecting gene expression.

• Diverse cellular responses, including changes in metabolic activity and gene expression.