PRINCIPLES OF SIGNAL TRANSDUCTIONA

Question 1

These molecules and proteins are key components for successful cell communication.

Answer 1

1. signaling molecules or the ligands
2. receptors
3. second messenger

Question 2

Most cells in multicellular organisms, both emit and receive signals.

Answer 2

Receptors

Question 3

Cell communication or signal transduction is mediated mainly by extracellular signal molecules (ligands)

Answer 3

Signaling molecules or ligands

Question 4

TRUE OR FALSE
The reception of the signal depends on receptor proteins, always at the cell surface, which binds the signal molecule.

Answer 4

False (usually, but not always)

Question 5

These targets are generally effector proteins, which are altered when the signaling pathway is activated and implements the signaling pathway is activated and implements the appropriate change of cell behavior.

Answer 5

Receptors

Question 6

What are the 5 modes of cell signaling?

Answer 6

1. Intacrine signaling
2. Autocrine signaling
3. Juxtacrine signaling
4. Paracrine signaling
5. Endocrine signaling

Question 7

Needs a cell to cell interactions
- signals are produced for adjacent cells

Answer 7

Paracrine signaling

Question 8

Takes place when the signal is directed to the same cell.
-This signal binds with a cell surface receptor, not a nuclear receptor.

Answer 8

Autocrine Signaling

Question 9

Happens when a signaling molecule or a ligand is acting inside a cell.

Answer 9

Intacrine signaling

Question 10

Is also known as contact-dependent signaling.
- The proximity between cells is mandatory for signaling to take place.

Answer 10

Juxtacrine signaling

Question 11

Uses hormones as signaling molecules.
- This is for signals that need to travel over long distance.

Answer 11

Endocrine signaling

Question 12

What are the types of cell-to-cell interactions?

Answer 12

1. tight junctions
2. anchoring junctions
3. communicating junctions

Question 13

In this type of interaction, direct physical contact is established that allows small molecules to pass.

Answer 13

Communication junctions

Question 14

Are also called occluding junctions.
- They connect the plasma membranes of adjacent cells and prevent leakage of small molecules from between them.

Answer 14

Tight junctions

Question 15

Are mechanically attached to the cytoskeleton of cell.
-They are usually found in the cells that make up the muscles and skins epithelium and can withstand some mechanical stress.

Answer 15

Anchoring junctions

Question 16

Is one type of anchoring junction that connects the action filaments of one cell of those of neighboring cells or with the extracellular matrix.
- It is mediated by a protein called integrin.

Answer 16

Adheren

Question 17

Are those that anchor epithelial cells to the basement membrane.

Answer 17

hemidesmosomes

Question 18

Are anchoring junctions that connect cytoskeleton of adjacent cells.

Answer 18

Desmosomes

Question 19

link in the junction hemidesmosomes are proteins called

Answer 19

cadherins

Question 20

Communicating junctions are also called?

Answer 20

Gap junctions

Question 21

These are complexes of six identical transmembrane proteins that allow passage of larger molecules like sugar and amino acids.

Answer 21

connexons

Question 22

What are the signaling molecules?

Answer 22

1. Gas
2. Steroids
3. peptide
4. neurotransmitters
5. neuropeptides
6. Polypeptide growth factors
7. second messengers

Question 23

A major paracrine signaling molecules. It involves in the functions of the nervous, immune, and circulatory systems

Answer 23

Nitric oxide (gas)

Question 24

-They act as hormones
-Small hydrophobic molecules making them easily cross the membranes.

Answer 24

Steroids

Question 25

TRUE OR FALSE
In Nitric oxide it diffuses across the plasma membrane and has a very short half-life, therefore it functions over long distances.

Answer 25

FALSE (short)

Question 26

Small proteins produced by neurons that act on G-protein-coupled receptors and are responsible for slow-onset, long lasting modulation of synaptic transmission.
- Function as neurotransmitter, as well as neurohormones.

Answer 26

neuropeptides

Question 27

Substances apart from the signaling molecules.
- They are used to relay the messages and usually used to amplify the signal

Answer 27

Second messengers

Question 28

Class of proteins which are bond by receptor protein and enable or disable biological pathway.

Answer 28

Peptide hormones

Question 29

Those that control the growth and differentiation cells.

Answer 29

Polypeptide growth factor

Question 30

Some of the receptors are always bond to the DNA even when the hormone is not present.

Answer 30

Thyroid hormone receptor

Question 31

Are those that interact with the signaling molecules and are found in the target molecules.
- They are unique structures on the plasma membrane

Answer 31

Cell surface receptors

Question 32

Carry signals between neurons (between synapses)
-They are hydrophobic molecules; hence, they are unable to cross the plasma membrane and bind to receptors.

Answer 32

Neurotransmitters

Question 33

-found in the cytosol, plasma membrane, and nucleus.
- Lead to the change in gene expression, causing an alteration in the transcriptional activity of the cell.

Answer 33

Steroid Receptors

Question 34

The largest group of enzyme-linked receptors.
-They have receptors for most polypeptide growth factors.

Answer 34

Tyrosine Kinase Receptor

Question 35

Are also known as TTM or seven transmembrane domain receptors.
- Pass through the plasma membrane seven times, forming many extracellular loops.

Answer 35

G-protein-coupled receptors

Question 36

Some can bind only when the hormone is there.

Answer 36

Estrogen and glucucorticoid receptors

Question 37

Include the receptor for most cytokines like interleukin 2 and erythropoietin and some polypeptide hormones.

Answer 37

Cytokine receptors