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

Stimulatory Adenylate Cyclase GPCR Signaling

Biochemistry

12. Biosignaling

Stimulatory Adenylate Cyclase GPCR Signaling

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Multiple Choice

When epinephrine binds to its GPCR activating the cAMP cascade, all of the following happen EXCEPT:

GDP dissociates from the G protein as GTP associates.

The alpha-subunit of the G protein activates adenylate cyclase and cAMP is produced.

G protein is activated and diffuses away from the cell membrane into the nucleus.

The alpha-subunit of the G protein hydrolyzes GTP and becomes inactive.

The alpha-subunit of the G protein bound to GDP reassociates with the beta & gamma-subunits.

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Verified step by step guidance

Understand the role of epinephrine in activating the GPCR (G-protein coupled receptor) and initiating the cAMP cascade. Epinephrine binds to the receptor, causing a conformational change that activates the G protein.

Recognize the process of G protein activation. When the GPCR is activated, the GDP bound to the alpha-subunit of the G protein is replaced by GTP, activating the G protein.

Identify the role of the alpha-subunit of the G protein. Once activated, the alpha-subunit dissociates from the beta and gamma subunits and interacts with adenylate cyclase, leading to the production of cAMP.

Understand the inactivation process of the G protein. The alpha-subunit eventually hydrolyzes GTP to GDP, which leads to its reassociation with the beta and gamma subunits, rendering the G protein inactive.

Clarify the incorrect statement: The G protein does not diffuse away from the cell membrane into the nucleus. It remains associated with the membrane, where it performs its signaling functions.