IB Biology: C2.1-Intracellular receptors and gene expression

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What characteristic allows many cell signal molecules to cross the cell membrane easily?

• They are large protein molecules.

• They are small lipid-soluble molecules.

• They require active transport.

• They are water-soluble ions.

Where do small lipid-soluble signal molecules interact with receptor proteins?

• Only on the cell surface membrane.

• In the cytoplasm or in the nucleus.

• Exclusively within the endoplasmic reticulum.

• Only outside the cell.

What prevents an intracellular receptor from binding to DNA in its inactive state?

• The receptor is located outside the nucleus.

• An inhibitor protein occupies the DNA binding site.

• The DNA binding site is not yet formed.

• The signal molecule is already bound.

What happens immediately after a signal molecule binds to an intracellular receptor, leading to gene transcription?

• The receptor is degraded.

• The inhibitor protein is released, exposing the DNA binding site.

• The receptor directly synthesizes mRNA.

• The cell membrane becomes impermeable.