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

Insulin Receptor

Biochemistry

12. Biosignaling

Insulin Receptor

Previous problemNext problem

Struggling with Biochemistry?

Join thousands of students who trust us to help them ace their exams!Watch the first video

Multiple Choice

Which of the following is TRUE concerning the interaction between the insulin receptor and IRS-1:

The IRS protein phosphorylates the insulin receptor.

The β-subunits of the receptor bind to insulin, where each subunit has a separate insulin binding site.

Each β-subunit acts as a serine kinase and auto-phosphorylates the other subunit.

IRS is phosphorylated by the tyrosine kinase domains in the β-subunits of the insulin receptor.

IRS contains phosphorylated threonine residues that directly bind to insulin.

Previous problemNext problem

Verified step by step guidance

Understand the role of the insulin receptor: The insulin receptor is a transmembrane receptor that is activated by insulin. It is composed of two α-subunits and two β-subunits.

Identify the function of the β-subunits: The β-subunits of the insulin receptor have intrinsic tyrosine kinase activity, which means they can phosphorylate tyrosine residues on target proteins.

Clarify the role of IRS-1: IRS-1 (Insulin Receptor Substrate 1) is a key signaling molecule that becomes phosphorylated on tyrosine residues by the activated insulin receptor.

Examine the interaction between the insulin receptor and IRS-1: Upon insulin binding, the β-subunits of the receptor undergo autophosphorylation, which activates their kinase activity. This leads to the phosphorylation of IRS-1 on specific tyrosine residues.

Conclude the correct statement: The correct interaction is that IRS-1 is phosphorylated by the tyrosine kinase domains in the β-subunits of the insulin receptor, facilitating downstream signaling pathways.