Homework 2 Communication, Integration & Homeostasis

Question 1

Briefly explain the similarities and differences between paracrine and autocrine chemical signals, Nero transmitters and neurohoromones

Answer 1

Paracrine signal: Signal sells next to a nearby
autocrine signal: Signals it’s self to release a receptor for binding
Both: Process of diffusion with local communication
Neurotransmitter: signaling molecule in cell.
Neurohormone: when neurotransmitter diffuses out of cell into the blood becomes the hormone. Example: ADH
Both: from nervous system

Question 2

Let’s the four classes of membrane receptors and briefly describe the actions of each

Answer 2

• Receptor channels: controls passage of ions through/across membrane Ligand gated channel. When ligand binds the gate opens and closes.
• intrgin receptor: Ligand activates some sort of intracellular response example blood clot
• Receptor enzyme complex: ligand activates the enzyme after binding to the receptor
• G protein coupled receptor: opens and closes ion channel that starts a cascade of reactions inside the cell

Question 3

Are all the receptors located in the cell membrane? Explain your answer and if no explain which type of molecules may interact with non-membrane receptors

Answer 3

No not all receptors are located on the cell membrane. The receptors that are located inside the cell need a ligand that can cross the cell membrane lipophilic and non-polar

Question 4

Briefly explain the concept of signal transduction and include a diagram or list outlining components of a typical transduction pathway

Answer 4

Signal transduction is the transfer of information from one side of the cell so the other side. Intracellular fluid, extracellular fluid to enact a response. Signal, receptor, transducer, amplifier, response

Question 5

For second messenger cAMP list substrate, amplifier enzyme, and general action

Answer 5

(Nucleotide)
Substrate: ATP
Amplification enzyme: adenylyl cyclase
General action: activates protein kinase, especially PKA binds to ion channel.

Question 6

For second messenger cGMP list the substrate, amplification enzyme and general action.

Answer 6

(Nucleotide)
Substrate: GTP
Amplification enzyme: guanylyl cyclase
Action: activates protein kinase

Question 7

For second messenger IP3 and DAG name substrate, amplification enzyme, and general action.

Answer 7

(Lipid derived )
Substrate: membrane phospholipids
Amp enzyme: phospholipids c membranes
General action: ip3 ; releases ca2+ from intracellular stores. DAG ; activates protein kinase c.

Question 8

Describe where calcium ions are stored in the cell and list the effects that they have as a second messenger

Answer 8

Calcium ions are stored in the endoplasmic reticulum inside the cell. they cause activation of downstream targets. Alter enzyme activity, exocytosis, muscle contractions, opens and closes ion channels

Question 9

Your mom and dad have been looking over your shoulder while studying and ask what the heck is protein kinase?’s explain it to them and simple yet complete terms

Answer 9

Pro Tien kinases a phosphorylated pro Tien enzyme this is an important intracellular enzyme that plays a crucial role in most signal transduction cascade by transferring a phosphate group onto a target pro Tien changing the proteins function from inactive to active

Question 10

Explain why we as physiologist care about protein kinase? What the heck does a phosphorylated protein do? And where do these magical phosphate groups come from?

Answer 10

A phosphorylated proTien Catalysis the transfer of the phosphate between their substrate this can have three possible effects. Protein activation, protein deactivation, or signal other proteins to interact with the target. We care because they play a crucial role and most signal transduction Cascades which are responsible for the majority of human cellular functions. They get their magical phosphate groups from ATP.

Question 11

Amplification

Answer 11

One signal molecule creates a larger signal

Question 12

Agonist

Answer 12

Activator receptor like it’s normal Ligand

Question 13

Cascade

Answer 13

A series of steps or events in a reaction

Question 14

Antagonist

Answer 14

Binds to receptors but blocks it’s activity

Question 15

Transducer

Answer 15

Convert a signal from one modality to another

Question 16

Briefly explain up regulation and down regulation what do the terms mean, how are they utilized by the body, and how are they enacted by cells?

Answer 16

Up regulation is when there are more receptors inserted into the cell to increase the level of saturation and sensitivity to a ligand.
Down regulation they take away the receptors on the cell making them become less sensitive to the ligand.
They are in active through endo ans exocytosis. And example is the uterus during pregnancy to uptake more hormones