Steroid hormones result in:Group of answer choicesdirect gene activationhormone binding to a membrane-bound receptoractivation of a G proteinactivation of adenylate cyclaseproduction of 2nd messengersall of theseNext

When a steroid hormone binds to its target cell receptor, it:Group of answer choicesalters the membrane’s permeability to G proteins.is converted into cholesterol, which acts as a second messenger.causes the formation of releasing hormones.turns specific genes of the nuclear DNA on or off.causes the formation of cyclic AMP

Which of the following statements best describes an important characteristic of the general steroid hormone receptor mechanism of action?Group of answer choicesSteroid receptors are bound to response elements even before binding to their ligand.Coactivator complexes that are recruited to ligand bound receptor remove acetyl groups from histones.Steroid hormone receptors are bound to heat shock proteins (hsps) in the inactive state before binding to a hormone.Helix 12 of the ligand binding domain is always positioned the same way regardless of binding to an agonist or an antagonist.Steroid receptors are always found in the nuclear cell membrane, which is why they are called nuclear receptors.

Which statement is not correct for hormone action? Group of answer choices Steroid hormone action is generally shorter lasting than that of peptide hormones as peptide hormones function at a genetic level, stimulating gene transcription. G proteins form a link between hormone binding to the receptor and internal cellular responses. Adenylate cyclase converts ATP to cAMP which acts as a second messenger for the adrenalin signal transduction system. All hormones require relatively low concentrations to exert their effects. None of the above (all statements are true)

Peptide hormonesMultiple Choiceare able to pass through the membrane and bind to a receptor in the cytoplasm.bind to a receptor in the plasma membrane.act much more slowly than steroid hormones.initiate gene expression.are composed of a complex of four carbon rings.

13. Steroid hormones such as estrogen act on target cells bya. initiating ion channel activity.b. binding to membrane proteins.c. initiating DNA transcription.d. activating enzymes.e. binding to membrane lipids.