AP Bio Unit 4

Plant cells can exchange small soluble compounds with neighboring cells directly through junctions in the cell wall called -

• gap junctions

• thylakoids

• stomata

• plasmodesmata

Why do hormones not affect every cell in the body when they are released?

• All cells are affected by a hormone when it is released

• A cell needs a specific receptor for the hormone to be affected

• A cell must have the proper ATP levels to activate a cellular response

• Cells need compatible DNA for the hormone to activate transcription of a gene

Which of these is a common type of final response in a signal transduction pathway?

• Activation of a G-protein receptor

• Transcription of a desired mRNA sequence

• Formation of cAMP

• Phosphorylation cascade

What is a second messenger in signal transduction?

• DNA

• cAMP

• Ligand

• Kinase

What are the three parts of signal transduction pathway?

• reception, transduction, response

• confirmation, transduction, transcription

• reception, amplification, transcription

• confirmation, amplification, response

If a medicine works by blocking a secondary messenger, what effect would it have on that cell signaling pathway?

• It would increase the response if the pathway

• It would trigger the release of more ligands

• It would activate the transcription of a desired gene

• It would inhibit transduction, thus deactivating the response

This diagram shows transduction of a signal. How is the signal being transduced to its target location in the cell?

• A hormone is binding to an intracellular protein receptor

• Transport vesicles are passing neurotransmitters to neighboring cells

• Enzymes are passing phosphate groups down a series of proteins

• cAMP is formed activating a desired response

Which part of the signaling pathway could consist of protein modification, second messenger production, amplification or a phosphorylation cascade?

• Reception

• Transduction

• Response

• All of these

Figure 1 shows a model of a signal transduction cascade, initiated by the binding of a ligand to the transmembrane receptor protein A. A DNA mutation changes the shape of the extracellular domain of transmembrane receptor protein A produced by the cell. Which of the following predictions is the most likely consequence of the mutation?

• Production of activated molecule 1 will stop, but production of activated molecules 2 and 3 will continue.

• The molecule that normally binds to protein A will no longer attach, deactivating the cellular response.

• The molecule that normally binds to protein A will not enter the cell, thus no cellular response will occur.

• Since protein A is embedded in the membrane, the mutation will be silent and not affect the cellular response.

Tags

NGSS.HS-LS3-2

Which of the following would NOT result in the inhibition of this pathway?

• A change in the shape of the receptor

• The presence of a competitive ligand

• Increase in hormone concentration

• Loss of second messenger production