Question

Describe stages of cell signaling: a. List and describe the three stages of cell signaling. b. List the three types of receptors and describe functions (pathways they are important in) of each of the three types of receptors.

Answer 1

Answer:

a. Reception: This stage is when the signal molecule binds to the receptor

b. Signal Transduction: This stage occurs where the chemical signal results in a series of enzyme activations

c. Signal Response: This is the stage that occurs as a result of cellular response

The three types of receptors are as follows:

Cell surface receptors/Ion channel-linked receptors: These channels open in response to the binding of a ligand to form a channel, it has a hydrophilic (water-loving) channel through the middle of it which allow a channel for the ions to cross the membrane without having to touch the hydrophobic core of the phospholipid bilayer.

G-protein-linked receptors: A family of cell surface receptors that share a common structure and method of signaling and are very diverse and bind to many different types of ligands, with seven different protein segments that cross the membrane, and they transmit signals inside the cell through a type of protein called a G protein

When its ligand is not present, the receptor waits at the plasma membrane in an inactive state and the inactive receptor is already docked to its signaling target which is a G-protein  

Enzyme-linked receptors: These are cell-surface receptors with intracellular domains that are associated with an enzyme and the domain is usually an enzyme that can catalyze a reaction. Other enzyme-linked receptors have an intracellular domain that interacts with the actual enzyme

Answer 2

Answer:

a.There are three signaling pathway

1- Reception in which molecule binds to receptor

2- Signal transduction in which activation of intracellular pathway and enzyme occur.

3- Cellular response in which specific response of cell occur according to receptor and ligand.

b. Three types of receptors are

1- autocrine

2- paracrine

3- endocrine.

Explanation:

autocrine receptors are signaling pathway in which cell releases its molecule and bind to its own cell receptor example cancer cells while paracrine in which ligand binds to other nearby cell receptor and it is used during development  and in endocrine cell target distinct cell and travel through blood stream like hormones functioning.