Unit 4 Review Cell Comunication

Which hormone is most directly related to osmoregulation?

• Insulin

• HGH

• ADH

• Adrenaline

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

• gap junctions

• thylakoids

• stomata

• plasmodesmata

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

A mutation in a cell membrane receptor would most likely have what effect on a signal transduction pathway?

• Reduce the response of the pathway

• An alternative response will be expressed

• Increase ligand binding

• Increase ligand release from the effector cell

Glucagon causes the breakdown of stored glycogen into glucose for cells. What conditions would trigger the release of glucagon?

• High blood sugar

• Low blood pH

• High heart rate

• Low cellular ATP concentration

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

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

Secondary messengers that can activate or deactivate enzymes in a cell are typically part of which step of cell signaling?

• Reception

• Transduction

• 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

When we are dehydrated, ADH is released which causes more water to be absorbed into our bloodstream. What type of feedback does this represent?

• Positive feedback

• Negative feedback