BIOD27: Endocrinology (TT1) Flashcards
what is the function of the parathyroid glands?
play an important role in regulating blood calcium
what is the function of the atrial natriuretic peptide (ANP)?
promotes the urinary excretion of sodium from the body
paracrines vs. autocrines
paracrines: exerts effects on local/nearby cells
autocrines: chemicals that exert effect on cells that produced them in the first place (ie. affects itself)
attaches a sugar, usually to an “N” or “O” atom in an a.a. side chain
glycosylation
adds an acetyl group to the N-terminus of a protein to increase stability
acetylation
covalently links the “S” atoms of 2 different cysteine molecules
disulfide bond
attaches a lipid to a protein chain
lipidation
adds a phosphate to serine, threonine, or tyrosine
phosphorylation
leptin vs. ghrelin
leptin: suppresses appetite
ghrelin: increses appetite
what is the role of C-peptide in the prohormone?
helps to make sure that the 2 parts that need to be linked together has the right orientation for folding and so that we can put disulphide bonds in the right place (Connecting peptide)
the rough ER is an _____ environment whilte the cytosol is an _____ environment
the rough ER is an oxidizing environment whilte the cytosol is a reducing environment
an aqueous pore in the ER membrane through which secreted proteins pass during translation
translocon
what helps create diversificaton in peptide hormones?
- transcription of multiple homologous genes
- transcription machinery at different sites on all genes
- alternative splicing of transcripts (exons)
- protein cleaved in different ways to create different fragments
the only 2 locations within the vertebrate body where steroid hormones are produced
adrenal and gonadal
most basic steroid hormone, as just involves removal of part of the cholesterol side chain
pregnenolone
what are the 2 major places to find enzymes necessary for steroid hormone synthesis
mitochondria and smooth ER
(most found in smooth ER)
3 general types of reactions in steroid hormones
- hydroxylations
- dehydrogenations
- C-C bond breakage
what is the active form of vitamin D called?
calcitriol
what are eicosanoids?
they are derivates of arachidonic (aka fatty) acids
a protein that is always involved in forming vesicles within cells
clathrin
what are the 3 major hormones that the pancreas produces?
- insulin
- glucagon
- somatostatin
what are the advantages to a pulsatile hormone release?
- info can be coded in amplitude or frequency of pulses
- more energetically-efficient and less cellular stress
- prevents receptor desensitization
what are 2 factors that determine half-life of hormones?
- how quickly it equilibrates w/ extravascular fluid and/or adipose tissue
- how quickly it is degraded
transformation of steroids to get degraded?
reduction then conjugation before excretion (70% in urine, 20% in bile)
the bigger KD (dissociation constant) is, the (faster/slower) the rate of hormone degradation
the bigger KD (dissociation constant) is, the FASTER the rate of hormone degradation
rate constants: K1 vs. K2
K1: rate at which hormone-receptor complex forms
K2: rate at which hormone receptor degrades
states that cells express much higher concentrations of hormone receptors than is needed to bring about a maximum biological effect
spare receptor hypothesis
intracellular receptors: zinc finger
D box (C II): generalized DNA binding region
P box (C I): allows for protein to bind to a very specific DNA sequence
posterior pituitary gland: components
infundibular stalk
pars nervosa
anterior pituitary gland: components
pars tuberalis
pars intermedia
pars distalis
refers to bundle of axon running from hypothalamus to posterior pituitary gland
supraopticohypophyseal tract
role of prolactin in different vertebrate groups
mammals: milk production
birds: fat metabolism
fish: salt and water balance
amphibians: metamorphosis and maturation
