ch 1+3 Flashcards
in an ELISA, the reporter enzyme is linked to the
a detection antibody
the endocrine system regulates:
metabolism, growth, development, reproduction, behavior, development, bodily fluids
building blocks of cells
nucleic acids, carbs, lipids, proteins
endocrine pathway
stimulus > endocrine cell > blood vessel > target tissue > response
autocrine
regulates itself
paracrine
local effect, cells next to each other can regulate each other
endocrine
two cells involved and the bloodstream, not local; receiving cell is further
endocrine and nervous systems
interact and regulate each other; neuroendocrine communication with neurohormones
Arnold Berthold
zoologist that tested roosters to remove testes (to become more docile) and made capons (smaller than average rooster). concluded that the testes are required for proper development into a rooster (better meat)
Arnold Berthold Experiment
group 1 (castration) - caponization
group 2 (reimplantation) - rooster
group 3 (transplantation) - rooster
Thomas Addison
Addison’s Disease
- adrenal insufficiency (1849)
Charles Hilton-Fagge
crenitism (neonatal hypothyroidism)
endocrine replacement theory proposed (Charles Brown-Sequard)
Bayliss and Starling
- process of digestion of a dog
- found first hormone (secretin)
- activates pancreas by small intestines
Chemical messenger
type of intercellular communication, chemical composition, mechanism for transport in blood (hormones and neurohormones only), mechanism for activation of their target cell
hydrophobic
- thyroid hormone (amine messengers)
- steroids
- eicosanoids
a- utilize intracellular receptors for activation of their target cell - cytoplasmic receptor
- nuclear receptor
- TRH > TSH
- can move across membrane
hydrophilic
can’t be moved across plasma membrane
- soluble in blood
- no carrier proteins
protein and peptide messengers
catecholamines and serotonin (amine messengers)
- cell surface receptors
- utilize cell-surface receptors for activation of a target cell
- can trigger an intracellular signal transduction pathway
hormone assays
immunological assays, biological assays, chemical assays
immunoassays
radioimmunoassay and ELISA
antibody
protein made by an animal in response to defend against the antigen
antigen
foreign molecule that is recognized as foreign by an animal’s immune system (hormone of interest)
RIA materials
capture antibody (hormone specific antibody)
detection antibody (an antibody to the capture antibody)
labeled hormone: radioactive
unlabeled hormone: not radioactive
standard curve samples: known hormone concentration
experimental samples: unknown hormone concentration
- microtiter plate
RIA advantages
- highly sensitive
- highly specific
- quantification is possible
RIA disadvantages
- radioactivity
- can’t determine if biologically active
ELISA
capture antibody: hormone-specific antibody
detecton antibody: antibody to the capture antibody
- linked to a “reporter enzyme”
hormone samples:
- standard curve samples: known concentration
- experimental samples: unknown concentration
biochemical reaction
microtiter plate
E+S > ES > EP > E+P
- the more enzymes, the faster the reaction and product
- spectrophotometer
ELISA advantages
specific and sensitive
quantification is possible
ELISA disadvantages
can’t tell if biologically active
chemical assays
based on chemical and physical properties
- size, change, polarity, solubility
- chromatography
bioassays
measures specific biological response following exposure to a substance- hormone
- obtain measurements to determine a biological response
- body weight, liver weight, bone growth
in-vivo
inside body
in-vitro
outside body
bioassay advantages
can tell biological activity
bioassay disadvantages
not very sensitive
difficult to perform
time consuming and sacrifices animals
intracellular signaling pathway
aka cell signaling pathway
- involves signal transduction pathway
cellular response
change in gene expression
change in intracellular ion concentration
hormone secretion
cell growth and division
- increased blood glucose
- less urine
- muscle contraction
receptors + intracellular signaling pathways
ligand aka extracellular signaling molecule
- ex. hormone
- def. molecule that binds to a receptor
steps of cell signaling for cell surface receptors
signal reception, signal transduction, (relay molecules in a signal transduction pathway), cellular response
signal transduction
types:
- intracellular signaling proteins
- G proteins
- second messengers (non-protein)
G protein coupled receptors (GPCR)
- snakes through the cytoplasm
- 7 transmembrane receptors
- two functional domains
- ligand binding domain: extracellular domain
- signal transduction domain: intracellular domain
G proteins structure
heterotrimeric protein anchored to the plasma membrane
- alpha, beta, gamma
G proteins: activation and inactivation
like “on/off” switches, alternating between active and inactive
GTP: guanosine triphosphate (guanosine -P-P-P) MORE ENERGY
- GDP: guanosine -P-P
- inactive G-protein: bound by GDP
- active G-protein: bound by GTP
process for activating G protein
ase means enzyme
two major types of G alpha subunits:
- G alpha s: activates adenylyl cyclase (stimulates cAMP production)
- G alpha q: activates phospholipase C (PLC) (stimulates Ca 2+ release)
protein kinases
enzymes that phosphorylate (adds phosphates to) other proteins
- can activate the protein
calmodulin
Ca2+ effector protein
intracellular receptors
intracellular signaling- nuclear receptors
- signal reception, transduction, (NO relay molecules or signal transduction pathway), response
nuclear receptors: structure
three functional domains
- ligand binding domain
- DNA binding domain
- transcription activation (activating) domain
hormone responsiveness
magnitude of a target cell’s response
- magnitude can depend on
1. concentration of the signaling molecule present
2. number of receptors present on a target cell
3. affinity of the receptor for its signaling molecule
4.
purpose of ELISA
look for color change
purpose of RIA
antigen concentrations, ex hormone levels in blood
amine
1 amino acid (modified)
- serotonin, melatonin, T3+T4 (thyroid hormone)
thyroid hormone hydrophobic
serotonin, melatonin hydrophilic
peptide/protein
3-50 amino acids: insulin, FSH, LH
lipid
steroids (estrogen, progesterone, testosterone, androstenedione) and eicosaniods (prostaglandins)
steroids (cholesterol)
eicosanoids (fatty acids)
neurosecretory cells
neurons that release into the blood (ant. pituitary and hypothalamus)
GH pathway
tropic: stimulates another gland to secrete (target the liver to make IGF-1)
- GRH (hypothalamus) > GH (anterior pituitary) > liver > IGF 1
GH nontropic
lengthening of bones
- muscle, bone, fat from IGF 1
- stimulates growth through IGF-1
gluconeogenesis
non-carbohydrate sources: burning through fat to make carbs
