Ap biology chapter 11

Concept review 11-1
1.nerve cells provide examples of both local and long-distance signaling.
Synaptic signaling, a specialized type of local signaling, occurs in the nervous system. An electricalsignal along a nerve cell triggers the secretion of a chemical signal in the form of neutrotransmitter molecules. That signal then can be considered as long-distance signal because it travels fromone cell to another.

2. When epinephrine is mixed with glycogen phosphorylase and glycogen in a test tube, is glucose-1-phosphate generated? Why or why not?
No, because it needs an intact cell totake place.

Concept review 11-2
1. In the plasma membrane, because a) that is where most water-soluble molecules are located, and b) it cannot pass through the lipid membrane.

Concept review11-3
1- A protein kinase is an enzyme (which is a protein) that takes phosphate groups from ATP and gives them to a protein. They activate other proteins, which means they are passing on theinformation.
2- A cell's response can be turned off by protein phosphatases, which remove phosphate groups from proteins (this is called dephosphorylation).
3- IP3 opens the gate between the ER and thecytosol. This allows Ca to exit into the cytosol, therefore IP3 increases the concentration of Ca in the cytosol.

Concept review 11-4
1- A target cell's response can be amplified because in every stepof the phosphorylation cascade, the signal is sent to more molecules.
2- Two cells with different scaffolding proteins could behave differently because the proteins do not react in the same way sincethey're not the same.

11.4. Response: Cell signaling leads to regulation of cytoplasmic activities or transcription
11.4.1. Cytoplasmic and nuclear responses
11.4.1.1. Transduction leads toregulation of cellular activities.
11.4.2. Fine-Tuning of the response
11.4.2.1. Signals with multiplicity of steps amplify the signal and contribute to the response.
11.4.3. Signal amplification...