PP Clues - Cell Physiology Flashcards
3 exceptions to the water out, fat in rule
Channels
Pores
Transmembrane proteins
RDA for fats, carbs, proteins
Fat = 30% (9cal/g) Proteins = 30% (4 cal/g) Carbohydrates = 40% (4cal/g)
7 functions of a cell membrane
Provide structure Transport (Motility) Active transport Heat/temp regulation Maintain gradient Depolarization Signal transduction
Membrane transportation in a cell
Phagocytosis
Bringing something into a cell
Endocytosis
Removing something from a cell
Exocytosis
Bring water into a cell
Pinocytosis
Two things required for cellular transport
ATP and Actin
Most important substance that is endocytosed
Nutrition
Most important substance that is exocytosed
Waste
Most important waste product produced by cells
Lipofuscin (brown pigment)
Most important factor in the movement of particles
Concentration gradient
How do you concentrate any substance in the body?
ATPase
Secondary active transport
Going with concentration gradient using another substance’s gradient
Most common gradient used for secondary active transport
Na+
Fat soluble and steroid hormone receptors
Have nuclear membrane receptors (except cortisol)
Readily cross the membrane
How do nuclear receptors work?
Stimulate the nucleus to perform DNA replication, transcription, translation into proteins by which they manifest their actions
How to differentiate between one fat soluble hormone and another?
By the proteins they make
Factors affecting transportation of water-soluble compounds
Size Charge pH Surface area Membrane thickness Flux Reflection coefficient Fick's law
How do ions cross membranes?
Channels
How do medium-sized particles cross membranes?
Pores
How do larger molecules cross membranes?
Transport proteins
How the body gets rid of heat
Vasodilate
How the body keeps heat
Vasoconstricts
Most important substance transported through pores
Sweat (NaCl and water)
Hormones that have cell membrane receptors
Non-steroid hormones
Most common extracellular cations/anions
Sodium/Chloride
Most common intracellular cations/anions
Potassium/Proteins
Tissues best at depolarizing
Neuronal and Purkinje fibers
Type of hormones that have second messengers
Water-soluble (protein)
Location of protein hormone receptors
Cell membrane
Reflection coefficient for protein hormones
Close to 1
6 classes of second messengers
cAMP cGMP IP3/DAG Ca2+ Tyrosine Kinase Nitric Oxide
Action of cAMP
2nd messenger for sympathetics
Action of cGMP
2nd messenger for parasympathetics
Action of IP3/DAG
2nd messenger for all hypothalamic hormone (except CRH)
All SM contraction by hormone or NT
Action of Ca2+ as a second messenger
Stimulates Gastrin
Action of tyrosine kinase
2nd messenger for insulin and all GF
Action of nitric oxide
2nd messenger for nitrates
MC second messenger system
cAMP
Hormones activated by phosphorylation
Catabolic
Hormones activated by dephosphorylation
Anabolic
Enzyme that breaks down cAMP
Phosphodiesterase
Inhibits phosphodiesterase
Caffeine
Theophylline
Bacteria that ADP-ribosylates Gs subunit of the G-protein
ETEC
Vibrio
Bacteria that ADP-ribosylates Gi subunit of the G-protein
Pertussis
Bacteria that ADP-ribosylates EF2
Diphtheria
Pseudomonas
Action of nitric oxide
Increases cGMP
2nd messenger systems enhanced by increase Ca2+
IP3/DAG
Ca2+/Calmodulin
Ca2+
Hypertensive medications that vaso & veno dilate
Nitrates
ACE inhibitors
Substances that use nitric oxide as second messenger
ANP
Endotoxin
Viagra (Sildenafil)
All nitrates
Nitrate used to TX cyanide poisoning
Amyl nitrate