Lecture 6 Chemical messengers

Question 1

Intercellular Communication

Answer 1

-Cells communicating with Each other

Question 2

Types of intercellular communication

Answer 2

1.Direct
-Gap Junctions:pores(connexons)
connecting adjacent cells together
1.Indirect
-Chemical messengers

Question 3

Classification of chemical messengers

Answer 3

1. Funtional
2. Chemical properties
3. Chemical Class

Question 4

Functional Classification

Answer 4

1. paracrines
2. Neurotransmitter
3. hormones

Question 5

Paracrines

Answer 5

• Chemicals that communicate w/ neighboring cells (tissue level)
• Distance:Short
• Mode of transportation:Diffusion

Question 6

paracrines Include

Answer 6

Autocrines;Chemicals that act on the same cells that secreted them

Question 7

Examples of Paracrines

Answer 7

Growth Factors, Clotting factors, cytokines

Question 8

Neurotransmitters

Answer 8

• Chemicals released by neurons to Synapse to the target cells
• Distance:Short
• Mode of transportation: Diffusion

Ex.Acetylcholine

Question 9

Hormones

Answer 9

• Chemicals Released from Endocrine glands,or neurosecretory neurons to ISF then to the Blood
• Distance:Long
• Mode of transportation:Blood

Question 10

Chemical Properties Classification

Answer 10

1. Lipophilic

2. Lipophobic

Question 11

Lipophilic

Answer 11

• lipid soluble (Non-Polar)

- Acts on Receptors inside the cells

Question 12

Lipophobic

Answer 12

• Water Soluble (polar)

- Acts on Receptor on cell membrane

Question 13

Chemical Classes

Answer 13

1. Amino acids
2. Amines
3. peptides and protiens
4. Steroids
5. Eicosanoids

Question 14

Amino Acids

Answer 14

• Basic monomars for properties
• Chemical property:Lipophilic (on surface)(polar)
• Functional Classification: Neurotransmitter (NT)

Ex.Glutamine,aspartate,glycine,GABA

Question 15

Amines

Answer 15

• Derived From Amino Acids
• Contains -NH2 group
• Chemical property:Lipophobic(except for thyroid hormones)
• Functional Classification: Paracines, NT, Hormone

Question 16

Examples of Amines

Answer 16

Dopamine ,Seotonin, norepinephrine, Epinephren, Histamine, thyroid hormes (lipo philic)

Question 17

Peptides and protiens

Answer 17

• Chain of amino acids
• most common
• chemical property:Lipophobic
• Functional Classification:paracrines,NT,Hormones

Question 18

Examples of Peptides and protiens

Answer 18

Cytokines,variety of NT and Hormones

Question 19

Steroids

Answer 19

• Derived for Cholesterol
• Chemical property;Lipophilic
• Functional Classification:Hormones

Question 20

Examples of Steroids

Answer 20

testosterone, cortisol, aldosterone, progesterone

Question 21

Eicosanoids

Answer 21

• Derived from Arachidonic Acid(Fatty acids)
• chemical property:Lipophilic
• Functional Class:paracrine

Question 22

Examples of Eicosanoids

Answer 22

prostaglandins, prostacyclines, thromboxanes ,leukotriens

Question 23

Signal Transduction Mechanism

Answer 23

1. Source releases a ligand(chemical messenger)
2. Travels to target cell
3. Ligand Binds to recptors on/in target cells for Functional Change

Question 24

properties of cell Receptors

Answer 24

1. messenger specific
2. Multiple Receptor types present on/in a cells
3. The more interactions, The Greater the affect

Question 25

Factors affecting interactions

Answer 25

1. messenger Concentration 2. # of receptors 3. Affinity

Question 26

Intracellular mediated Responce

Answer 26

``` Receptor:inside cell Messenger:lipophilic Responce:Gene activation or inhibition Effects: 1.slow ->protien synthesis takes time 2.Long lasting ->protiens llast a while ```

Question 27

Membrane Receptor Mediated Responce

Answer 27

``` Receptors:On membrane messenger:lipophobic Catagories; 1.Channel-linked 2.Enzyme-linked 3.protien linked ```

Question 28

Channel - Linked

Answer 28

- Receptor also acts as a channel | - Responc: Opens channels in membrane

Question 29

Enzyme-Linked

Answer 29

- Receptor also acts as an intracellular enzyme | - Responce: activates Enzyme