1.cAMP MOLECULES BIND TO THE ________ subunit of_______
a. catalytic, PKC
B. regulatory, PKA
C. Regulatory, PKC
d. Catalytic, PKA
I THINK THE RIGHT ANSWER IS "B", PLEASE HELP
To determine the correct answer, we need to understand the function of cAMP molecules and how they interact with different subunits of enzymes.
First, cAMP (cyclic adenosine monophosphate) is a signaling molecule commonly involved in cellular communication. It acts as a secondary messenger, transmitting signals from cell surface receptors to other targets within the cell.
Now, let's consider the two subunits mentioned in the question:
1. PKC (Protein Kinase C): PKC is an enzyme that phosphorylates target proteins, regulating various cellular processes. It consists of three subunits: catalytic, regulatory, and membrane-targeting.
2. PKA (Protein Kinase A): PKA is another kinase enzyme involved in phosphorylating target proteins. It also has three subunits: catalytic, regulatory, and regulatory.
Now, the correct answer is determined by understanding which subunit of which enzyme binds to cAMP molecules.
According to the question, cAMP molecules bind to the ________ subunit of _______.
- Option A: "catalytic, PKC" is incorrect because cAMP does not bind to the catalytic subunit of Protein Kinase C.
- Option B: "regulatory, PKA" is correct because cAMP molecules do indeed bind to the regulatory subunit of Protein Kinase A. This binding leads to the dissociation of the regulatory subunit from the catalytic subunit, subsequently activating PKA.
- Option C: "Regulatory, PKC" is incorrect because cAMP does not directly bind to the regulatory subunit of Protein Kinase C.
- Option D: "Catalytic, PKA" is incorrect because cAMP binds to the regulatory subunit of PKA, not the catalytic subunit.
Therefore, the correct answer is Option B: cAMP molecules bind to the regulatory subunit of PKA.