Cell Communication
What is the primary purpose of cell communication?
To allow cells to coordinate their activities and respond to changes in their environment.
What is signal transduction?
The process by which a cell responds to external signals through a series of molecular events.
What are the 2 main phases of the cell cycle?
- Interphase
- M phase
What are cyclins, and what role do they play in the cell cycle?
Cyclins are proteins that regulate the cell cycle by activating cyclin-dependent kinases (CDKs).
Identify two types of cell communication (signaling) AND give a brief description of the type of communication
- autocrine - signals self
- juxtacrine - signals between cells in direct contact
- paracrine - signaling between cells a short distance away
- endocrine - signaling between cells that are a long distance away, through the blood stream
Name the three main stages of signal transduction.
- reception
- transduction
- response
What occurs during the S phase of the cell cycle?
DNA replication
MPF is made of a combination of 3 molecules. Identify these 3 molecules.
- cyclin
- CDK
- phosphate
Describe the role of receptors in cell communication.
Receptors bind to signaling molecules and initiate a cellular response.
What do we call the act of a phosphate being added to a molecule?
What type of molecules are responsible for adding these phosphate groups in a signal transduction pathway?
- phosphorylation
- protein kinases
How does cytokinesis differ from mitosis?
- cytokinesis - division of cytoplasm
- mitosis - division of nucleus
Explain the function of tumor suppressor genes in cell cycle regulation.
Tumor suppressor genes prevent uncontrolled cell division by repairing DNA or initiating apoptosis.
Identify 2 types of molecules (general) or specific molecules used for cell signaling.
- hormones
- neurotransmitters
- epinephrine
- testosterone, estrogen, progesterone
What do we call the act of a phosphate being taken way from a molecule?
What type of molecules are responsible for taking away these phosphate groups in a signal transduction pathway?
- dephosphorylating
- protein phosphatases
- When a cell is not signaled for cell division, usually due to density-dependent inhibition, what happens to the cell?
- It goes into G0
What happens when cell cycle regulation fails?
Failure in regulation can lead to uncontrolled cell growth and cancer.
Explain how gap junctions facilitate cell communication.
Channels that allow direct communication between adjacent cells by permitting the passage of ions and small molecules.
- Identify the receptor that is the most widely used receptor in cell signaling.
- Identify the receptor that is associated with the formation of tumors when the receptor isn't functioning properly.
- GPCR's
- RTK's
What is the role of checkpoints in the cell cycle?
Checkpoints monitor the cell cycle progression and ensure that conditions are favorable for division.
At which checkpoint will the cell check the amount of DNA replicated?
- G2