The enzymes that attach phosphate to proteins and play a major role in regulation in cell cycle are called
A. DNA polymerase.
B. growth factors.
C. proteases.
D. protein kinases.
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Cells in a multicellular organism also usually communicate by chemical messengers. They can communicate by direct contact through cell junctions that connect the cytoplasm of adjacent cells. What is the cell junction found in animal cells referred to as?
A. plasmodestmata
B. cytosol junctions
C. gap junctions
D. short distance junctions
There are differed signaling mechanisms found in cells. Which of the following are correctly paired?
A. gap junction - intravenous communication
B. endocrine - substrate communication
C. synaptic - neural communication
D. receptor - communication using hormones
In animal cells that lack the ability to produce GTP, what is the correct result for this signaling system?
A. It would not be able to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane.
B. It could activate only the epinephrine system.
C. It would be able to carry out reception and transduction but would not be able to respond to a signal.
D. It would use ATP instead of GTP to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane.
What is protein kinase, and what is its role in routes of transduction of chemical signals?
A. It is an enzyme that is embedded in plasma membrane that converts ATP in response to a signal.
B. It transfers a phosphate from ATP to a protein activating that protein.
C. It removes phosphates from proteins during dephosphorylation which stops the cell signaling.
D. It attaches sugar molecules into multiple compounds that the cell is able to use.
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