Table of contents

1. Introduction to Biochemistry4h 34m
2. Water3h 23m
3. Amino Acids8h 10m
4. Protein Structure10h 4m
5. Protein Techniques14h 5m
6. Enzymes and Enzyme Kinetics13h 38m
7. Enzyme Inhibition and Regulation 8h 42m
8. Protein Function 9h 41m
9. Carbohydrates7h 49m
10. Lipids5h 49m
11. Biological Membranes and Transport 6h 37m
12. Biosignaling9h 45m
Review 1: Nucleic Acids, Lipids, & Membranes2h 47m
Review 2: Biosignaling, Glycolysis, Gluconeogenesis, & PP-Pathway3h 12m
Review 3: Pyruvate & Fatty Acid Oxidation, Citric Acid Cycle, & Glycogen Metabolism2h 26m
Review 4: Amino Acid Oxidation, Oxidative Phosphorylation, & Photophosphorylation1h 48m

12. Biosignaling

Phosphoinositide GPCR Signaling

Biochemistry

12. Biosignaling

Phosphoinositide GPCR Signaling

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Multiple Choice

All G proteins are activated by GDP/GTP exchange (binding to GTP), but lose their activity when they hydrolyze GTP to GDP. However, different G proteins can have different roles. Which of the following is INCORRECT?

When active, G_αs activates adenylate cyclase.

When active, G_αs results in increased production of cAMP.

When active, G_αi results in the inhibition of adenylate cyclase.

When active, G_αq results in the activation of phospholipase C.

When active, G_αs results in increased production of inositol triphosphate.

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Verified step by step guidance

Understand the role of G proteins: G proteins are molecular switches that activate or inhibit various signaling pathways in the cell. They are activated by exchanging GDP for GTP and become inactive when they hydrolyze GTP to GDP.

Identify the specific G proteins mentioned: Gαs, Gαi, and Gαq. Each of these has a distinct role in cellular signaling pathways.

Review the function of Gαs: When Gαs is active, it stimulates adenylate cyclase, which increases the production of cyclic AMP (cAMP), a secondary messenger involved in many signaling pathways.

Review the function of Gαi: When Gαi is active, it inhibits adenylate cyclase, leading to a decrease in cAMP production.

Review the function of Gαq: When Gαq is active, it activates phospholipase C, which leads to the production of inositol triphosphate (IP3) and diacylglycerol (DAG), both of which are important secondary messengers. The incorrect statement is that Gαs results in increased production of inositol triphosphate, which is actually a function of Gαq.