Hormone classes and cellular signaling pathways

Question 1

What are Hormones?

Answer 1

Signaling molecules that relay information throughout the body to regulate biological activities

Question 2

What are the biological activities regulated by hormones?

Answer 2

• metabolism, growth, reproduction, behavior
• act in distant tissues as well as locally
• produced by specialized cells in large amounts to be able to reach target at effective connections

Question 3

Paracrine

Answer 3

Cell effects neighboring cells in same tissue

Question 4

Autocrine

Answer 4

Cell effects itself

Question 5

Why are hormones produced in large amounts to reach target?

Answer 5

Larger amounts to have enough when reaching target

Question 6

Where are cell surface receptors located?

Answer 6

Cell Membrane

Question 7

Classes of Hormones

Answer 7

Peptide/ Protein
Amino Acid Derived
Lipid Derived

Question 8

Peptides

Answer 8

Oxytocin, Vasopressin (AVP) , GnRH

Question 9

Proteins

Answer 9

TSH, FSH, LH, Insulin, Glucagon, Prolactin

Question 10

What do Peptide and Proteins have in common?

Answer 10

Genes
Come form the nucleus
- DNA, RNA, Transcription and Translation

Question 11

Monoamines

Answer 11

Norepinephrine, Epinephrine, Dopamine
- made from the amino acid tyrosine (specific amino acid)

Question 12

Steroids

Answer 12

Estradiol , Testosterone, Progesterone, Cortisol, Aldosterone
(all lipid derived)

Question 13

What do steroids have in common?

Answer 13

Made from cholesterol

Question 14

Steroids will not have…

Answer 14

will not have genes in DNA because it is made/synthesized by a series of enzymatic reactions, these enzymes are encoded by genes making the hormones

Question 15

Hormone receptors

Answer 15

Cell membrane receptors (GPCR) and Intracellular receptors (Nuclear receptor)

Question 16

G Protein-Coupled Receptors (GPCR) overview

Answer 16

1. hormone/ligand attaches to 7 transmembrane receptors
2. g protein» 3 subunits and is initially attached to GDP
3. becomes activated when GTP replaces GDP
4. activate g protein activates enzymes
5. initiating second messengers

Question 17

second messenger cAMP

Answer 17

• ACTH activated GS alpha subunit, g protein and enzyme
• activated enzyme ( Adenylyl Cyclase) finds ATP and converts it into cAMP
• cAMP activates PKA and goes into the nucleus
• before going into nucleus it releases PKA finds target proteins and activates by phosphorylating it ( short term effect
• in the nucleus PKA binds with inactive CREB to become activated , phosphorylated CREB that attaches to promoter region and activates transcription and translation (long term effect)

Question 18

second messengers calcium

Answer 18

• GnRH activates GQ alpha subunit
• g proteins activates PLC
• PLC hydrolyzes PIP2 breaking it apart into DAG and IP3
• IP3 stimulates ER and opens Calcium channels into cytosol
• calcium activates PKC forming phosphorated PKC
• calcium will also bind to CaM&raquo_space; which response to muscle contraction
  Calcium will also go into the nucleus and activates transcription of target genes + regulation

Question 19

Nuclear receptors super family

Answer 19

Steroid receptor family and thyroid receptor family

Question 20

Steroid receptor family

Answer 20

Corticoid , Androgen, Progesterone, and Estrogen

Question 21

Thyroid receptor family

Answer 21

Vitamin D, Thyroid, Retinoic Acid

Question 22

Differences between nuclear receptor superfamily

Answer 22

1. Hormones they bind to
2. Ability to form homodimer (steroids and thyroid) or heterodimer (thyroid)
3. Location in cell
   - steroids&raquo_space; cytosol before nucleus
   - thyroid&raquo_space; nucleus, already bond to DNA