Cell Physiology Flashcards
what tissues are the best at depolarizing?
- neuronal
- purkinje fibers
what are the most common intracellular cations/anions?
potassium and proteins
what type of hormones have second messenger systems?
- water-soluble (protein)
where are protein hormone receptors located?
cell membrane
what is the reflection coefficient for protein hormones?
close to 1
what are 6 classes of second messengers?
- cAMP
- cGMP
- IP3/DAG
- calcium
- tyrosine kinase
- nitric oxide
what is the action of cAMP?
2nd messenger for sympathetics EPI
what is the action of cGMP?
2nd messenger for parasympathetics
what is the action of IP3/DAG?
- 2nd messenger for:
- all hypothalamic hormones except CRH
- all smooth muscle contraction by hormones or neurotransmitters
what is the action of calcium-calmodulin?
2nd messenger of all smooth muscle contraction by distention
what is calcium a second messenger for?
gastrin
what is the action of tyrosine kinase?
2nd messenger for insulin and all growth factors
what is the action of nitric oxide?
2nd messenger for nitrates
what is the MC 2nd messenger system?
cAMP
what hormones are activated by phosphorylation?
all catabolic
what hormones are deactivated by phosphorylation?
all anabolic
what enzyme breaks down cAMP?
phosphodiesterase breaks down cAMP
what substrances inhibit phosphodiesterase?
caffeine and theophylline
what bacteria ADP-ribosylate Gs subunit of G-protein?
ETEC and vibrio
what bacteria ADP-ribosylate Gi subunit of the G-protein?
pertusses
what bacteria ADP-ribosylate EF-2?
diphtheria and pseudomonas
how does nitric oxide work?
increases cGMP
what second messenger systems are enhanced by increase in calcium?
- IP3/DAG
- calcium/calmodulin
- calcium
what hypertensive medications both vaso and veno dilate?
nitrates and ACE-inhibitors
what substance use nitric oxide as a second messenger?
- ANP
- endotoxin
- viagra (sildenafil)
- all nitrates
what nitrates is used to treat cyanide poisoning?
amyl nitrate
what nitrate is given IV or sub lingual for chest pain?
nitroglycerine
what nitrate is used to treat a hypertensive crisis?
sodium nitroprusside
what is the function of smooth ER?
detoxification and steroid synthesis
what is the function of rough ER?
makes proteins for packaging
what is the function of free ribosomes?
makes proteins for cytoplasm
what is the function of the lysosome?
degradation of waste
what is the function of golgi?
post-translational modifications of proteins
what is the function of mitochondria?
makes energy
what is the function of the nucleus?
contains genetic information
what is the function of the nucleolus?
produces ribosomal RNA
Damage to what orgenelles is irreversible?
- nucleus
- mitochondria
- lysosomes
what are 3 exceptions to the water-out, fat-in rule?
- channels
- pores
- transmembrane proteins
what is the RDA for fat/carb/protein?
30% fats
30% proteins
40% carbohydrates
what are the 7 functions of the cell membrane?
- provide structure
- transport
- active transport
- heat/temp regulation
- maintain gradient
- depolarization
- signal transduction
what is membrane transportation in a cell called?
phagocytosis
what is it called to bring something into a cell?
endocytosis
what is it called to put something outside the cell?
exocytosis
what is it called to bring something into a cell?
pinocytosis
what are the two things required for cellular transport?
ATP and actin
what is the most important substance endocytosed?
nutrition
what is the most important substance exocytosed?
waste
what is the most important waste product produced by cells?
lipofuscin (brown pigment)
what is the most important factor in the movement of particles?
cooncentration gradient
how do you concentrate any substance in the body?
with an ATPase
how does secondary active transport work?
going with a concentration gradiant using another substance’s gradent
what is the most common gradient used for secondary active transport?
Na
what is true for all fat soluble and steroid hormone receptors?
they never have cellular membrane receptors because they readily cross the membrane.
where are fat soluble and steroid hormone receptors located?
in the nucleus (except for cortisol with a cytoplasmic receptor)
how do nuclear receptors work?
stimulate the nucleus to perform DNA replication, transcription, and translation into proteins by which they manifest their action
how do you differentiate between one fat soluble hormone and another?
by the proteins they make
what factors affect transportation of water-soluble compounds or hormones?
- size
- charge
- pH
- surface area
- membrane thickness
- flux
- relfection coefficient
- Fick’s law
how does ions cross membranes?
through channels
how do medium-size particles cross membranes?
pores
how do larger molecules cross membranes?
transport proteins
how does the body get rid of heat?
vasodilate
how does the body keep heat?
vasoconstrict
what is the most important substance that is transported through pores?
sweat (NaCl and water)
which hormone have cell membrane receptors?
non-steroid hormones
what are the most common extracellular cations/anions?
sodium and chloride
what organ uses the SER for detoxification?
kidneys
what organ uses SER for steroid synthesis?
liver
what is the form of proteins when they start off?
pre-pro-protein
which is the only protein modified in the rough ER?
collagen
where are all proteins except collagen modified?
golgi
what are the tissues with the most SER?
liver and kidney
what substance do lysosomes have a lot of?
acid hydrolases
what do acid hydrolases do to the pH of lysosomes?
cause the pH to be very acidic
what is the structure formed when a lysosome phagocytoses something?
phagosome of phagolysosome
what component of tuberculosis prevents phagocytosis?
cord factor
what ion damages lysosomes by coating their surface?
calcium
what does damage to the lysosomes cause?
acid hydrolases leak out and damage the nuclease, particularly DNAse and RNAse
what is the most important primary active transport system?
gh