Cell Com Quiz CHS

A signal molecule that binds to a plasma-membrane protein is a

• ligand
• second messenger
• protein kinase
• receptor protein

Protein kinases activate other relay proteins by adding a(n) ____ to them.

• phosphate
• ATP molecule
• cAMP
• GTP

Each of the following numbered processes are involved in signal transduction pathways:  
 I.  Response  
II.  Amplification  
 III.  Reception  
IV.  Transduction
Which of the following represents the sequence of events in a typical signal transduction pathway?

• I, II, III, IV
• III, I, IV, II
• II, IV, I, III
• III, IV, II, I

Which letter represents the cell surface receptor protein?

• A

• B

• C

• D

• E

Which letter represents the ligand?

• A

• B

• C

• D

• E

Which of the following is a secondary messenger?

• cAMP

• ATP

• Protein Kinase

• Ligand

How are ligands cell-specific?

• Each cell has a different response to the ligand.

• Each cell has different receptors to bind to the ligand

• Each cell has different relay molecules based on the ligand.

• Each cell has different processes for endocytosis.

Describe the phosphorylation cascade.

• Protein phosphatase adds a phosphate to a relay molecule which causes a change in shape to activate.

• Protein kinase adds a phosphate to a relay molecule which causes a change in shape to activate.

• ATP adds a phosphate to a relay molecule which causes a change in shape to activate.

• Mitochondria adds a phosphate to a relay molecule which causes a change in shape to activate.

What does a protein phosphatase do?

• removes phosphates
• transfers phosphates from ATP to proteins
• activates an enzyme with a signal molecule

Receptors for signal molecules __________.

• can be found in the plasma membrane & in cytoplasm/nucleus

• all work via protein kinases

• all work by opening ion channels

• are only found associated with the plasma membrane