endocrine system + hormone types

Question 1

describe the endocrine system

Answer 1

• consists of a group of ductless glands that secrete hormones

Question 2

what are the endocrine glands?

Answer 2

• pituitary gland
• thyroid gland
• parathyroid gland
• thymus
• adrenal glands
• gonads
• pancreas

Question 3

describe hormones

Answer 3

• chemical messages
• proteins, amines + steroids
• secreted by endocrine glands
• carried in the bloodstream to target organs
• change the way cells function
• target specific orgnas

Question 4

describe protein hormones

Answer 4

• soluble in water (polar)
• cannot move through membrane = bind to receptors on the outside
• receptors are located outside of the cell membrane, they use receptor proteins embedded in the membrane
• responsible for enzyme amplification = fast action with short effect
• can be stored
  e. g. all the rest = thyroxine + ADH

Question 5

describe steroids

Answer 5

• insoluble (non-polar)
• diffuse through the phospholipid bilayer
• receptors are in the cytoplasm, nuclear membrane, or DNA
• cause a change in gene expression = epigenetics, cause proteins to be synthesized by expressing genes in DNA = slow-acting with long term affects
• cannot be stored
  e. g. all hormones made by gonads + adrenal cortex

Question 6

what is the first step of a steroid hormone transporting through a cell membrane?

Answer 6

• lipid soulable hormone diffuses through plasma membrane

Question 7

what is the second step of a steroid hormone transporting through a cell membrane?

Answer 7

• hormone binds with receptor in cytoplasm, forming a receptor-hormone complex

Question 8

what is the third step of a steroid hormone transporting through a cell membrane?

Answer 8

receptor-hormone complex enters the nucelus and triggers gene transcription

Question 9

what is the fourth step of a steroid hormone transporting through a cell membrane?

Answer 9

• transcribed mRNA is translated into proteins that alter cell activity

Question 10

what is the first step of a protein hormone transporting through a cell membrane?

Answer 10

• water soluble hormones are membrane insouluble = they bind to membrane receptors

Question 11

what is the second step of a protein hormone transporting through a cell membrane?

Answer 11

the binding activiates a G proteins which activates adenylyl cyclase

Question 12

what is the third step of a protein hormone transporting through a cell membrane?

Answer 12

adenylyl cyclase catalyzes the conversion of ATP to cAMP, the secondary messenger in this pathway

Question 13

what is the fourth step of a protein hormone transporting through a cell membrane?

Answer 13

cAMP activates protein kinases

Question 14

what is the last step of a protein hormone transporting through a cell membrane?

Answer 14

protein kinases phosphorylate proteins in the cytoplasm. this activates these proteins allowing them to alter cell activity