TopHat 11 Flashcards
A mutant form of a G protein lacks the ability to function as a GTPase. What effect do you think this would have?
A. No effect, other proteins can perform same function
B. G protein will remain inactive
C. G protein will be constitutively active
D. GDP will accumulate in cell
C
What characteristics allows some signaling molecules to pass through membrane to deliver their message
Hydrophobic
What is most likely to happen to an animals target cell that lacks receptors for local
A. Hormones would not be able to interact with target cells
B. They might not be able to multiply in response to growth factors from nearby cells
C. They could develop normally in response to neurotransmitters instead
B
Which of the following would be inhibited by a drug that specifically blocks the addition of phosphate groups to proteins?
A. Phosphate activity B. Ligand-gates ion channel signaling C. Receptor tyrosine kinase activity D. Adenylyl cyclase activity E. G protein-coupled receptor binding
C
Which of the following best describes a signal transduction pathway?
A. Binding of a signal molecule to a cell protein
B. Catalysis mediated by an enzyme
C. Sequence of changes in a series of molecules resulting in a response
D. Binding of a ligand on one side of a membrane that results in a change on the other side
C
What effect would you expect an inactive phosphatase to have on a signaling pathway?
A. The pathway would remain inactive
B. The pathway would be constitutively active
C. No effect, phosphatases only function to add phosphate groups to nucleus acids
B
Which of the following is true of transcription factors?
A. Initiate the epinephrine response in animal cells
B. Control gene expression
C. They regulate the synthesis of DNA in response to a signal
D. Regulate synthesis of lipids in cytoplasm
B
