6 public questions tagged with this topic.
Epinephrine (Adrenaline), secreted by the adrenal medulla, is the "fight-or-flight" hormone that prepares the body for emergency situations.
Ref: NCERT Class 11 Biology Chapter 19: Chemical Coordination and Integration Adrenal Gland - Cortex and Medulla
Epinephrine (Adrenaline), secreted by the adrenal medulla, prepares the body for emergency situations.
Ref: NCERT Class 11 Biology Chapter 19: Chemical Coordination and Integration Adrenal Gland - Cortex and Medulla
Adrenaline increases heart rate and blood pressure, not decreases it.
Ref: NCERT Class 11 Biology Chapter 19: Chemical Coordination and Integration Adrenal Gland - Cortex and Medulla
dephosphorylation, is consistent with established principles of cell signaling, receptor pharmacology and cellular regulation. Experimental measurements of binding parameters, genetic loss-of-function studies and pharmacological interventions all converge on the same interpretation. Related options address neighboring concepts but do not satisfy the precise criterion stated in the question.
Ref: NCERT Biology Class 11–12 Alberts et al Molecular Biology of the Cell Lodish et al, Molecular Cell Biology Cooper & Hausman, The Cell Abbas et al., Cellular and Molecular Immunology (for immunology sections)
Both β-adrenergic receptors and glucagon receptors couple to the stimulatory G protein Gs. Activated Gs stimulates adenylyl cyclase, elevating cAMP and activating protein kinase A. PKA phosphorylates enzymes of glycogen metabolism, ultimately raising blood glucose. Insulin opposes these effects by promoting dephosphorylation of the same target proteins, illustrating reciprocal control of carbohydrate homeostasis.
Ref: NCERT Biology Class 11–12 Alberts et al Molecular Biology of the Cell Lodish et al, Molecular Cell Biology Cooper & Hausman, The Cell Abbas et al., Cellular and Molecular Immunology (for immunology sections)
Tyrosine is the correct answer because it serves as the specific precursor, synthetic product, or metabolic intermediate described in this question. Biosynthetic pathways in Amino_Acids_Structure follow precise enzymatic steps where specific substrates are converted to products through regulated metabolic reactions. Tyrosine occupies a key position in this metabolic pathway due to its chemical structure and reactivity. The other options (Tryptophan, Phenylalanine, and Arginine) are involved in different biosynthetic routes, serve as precursors for different end products, or participate in unrelated metabolic conversions.
Ref: Campbell Biology, Urry et al., 12th Ed.
