Signal Transduction
This is what binds to a receptor.
Ligand
This is what happens to a signal through a transduction pathway.
Amplification
This type of regulation responds by amplifying the stimulus.
Positive Feedback
This part of the cell cycle contains G1, S, and G2.
Interphase
This phase is where the nuclear membrane reforms.
Telophase
This class is one of the most common receptors found in eukaryotes.
GPCRs
These proteins phosphorylate other proteins, causing activation or deactivation.
Kinases
This type of regulation responds to maintain homeostasis.
Negative Feedback
During which phase does DNA replication occur in the cell cycle?
S (synthesis) phase
This phase is where the nuclear membrane breaks down.
Prophase
This is the name of the enzyme that produces cyclic AMP.
Adenylyl cyclase
This type of ligand would have an intracellular receptor.
Steroid (lipid or nonpolar)
The release of oxytocin during childbirth is an example of:
Positive Feedback
The p53 protein is important in cancer prevention. Why?
Stimulates DNA repair mechanisms
This phase is where spindle fibers attach to chromosomes
Metaphase or Prometaphase
Ca2+ (calcium ions) are an important example of this.
Second messenger
In a signal transduction cascade, what typically happens to protein kinases?
They phosphorylate target proteins
After eating a meal, blood glucose levels increase. The pancreas detects this rise and releases insulin, a hormone that facilitates the uptake of glucose by cells and stimulates the liver to store glucose as glycogen. As glucose levels in the blood decrease, insulin secretion slows. Is this an example of a positive or negative feedback loop? Explain your reasoning.
This is a negative feedback loop because the response (insulin release) counteracts the initial stimulus (high blood glucose levels) to restore homeostasis. Once blood glucose levels are back to normal, the stimulus for insulin release is reduced.
These are the checkpoints of the cell cycle, in order.
G1, G2, M
This is what happens during anaphase.
Sister chromatids separate
This describes when a cell signals itself.
Autocrine
This describes a protein that can regulate gene expression.
Transcription Factor
When a blood vessel is damaged, platelets adhere to the site of injury and release chemicals that attract more platelets to the area. These platelets continue to release chemicals and increase the recruitment of even more platelets, until a clot forms and seals the wound. Is this an example of a positive or negative feedback loop? Justify your answer.
This is a positive feedback loop because the response (platelet recruitment) amplifies the initial stimulus (damage to the blood vessel). The loop continues until the clot is fully formed and the wound is sealed, stopping the feedback cycle
The retinoblastoma (Rb) protein functions primarily by:
Controlling G1/S transition
This regulatory molecule dramatically decreases in concentration during mitosis.
Cyclin