AP Biology - Cell Signalling and Transduction

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

• ligand
• second messenger
• protein kinase
• receptor protein

What is a G protein?

• specific type of membrane-receptor protein
• protein on the cytoplasmic side of a membrane
• membrane-bound enzyme
• relay protein

What do second messengers do?

• transport a signal through the lipid bilayer
• relay a signal from the outside to the inside of the cell
• relay message from the inside of the mebrane throughout the cytoplasm
• dampen the message

Signal amplification is most often achieved by

• an enzyme cascade
• binding of multiple signals
• branching pathways
• action of adenylyl cyclase

What does a protein kinase do?

• removes phosphates
• transfers phosphates from ATP to proteins
• activates an enzyme

Which of the following is a chemical message that usually travels through the bloodstream to target cells?

• hormone
• local regulator
• endocrine cell

Which molecule typically serves as a communicator for cells?

• Carbohydrates

• Lipids

• Proteins

• Nucleic Acds

Most hormones are proteins. Which other molecule type can serve as hormone?

• Carbohydrates

• Lipids

• Nucleic Acids

This hormone acts to raise blood glucose levels.

• insulin

• melatonin

• glucagon

• somatostatin

What type of receptor would testosterone have?

• Intracellular
• Membrane