Flashcards in Biological Trends Improvement Deck (23):
Stretch of lung
Increase in CO2
Decrease in pH. Increase respiratory rate
Decrease in O2
Increase in respiratory rate
Where are peripheral chemoreceptors
Aorta and carotid arteries
What do peripheral chemoreceptors sense
CO2, pH, and O2 in blood
Where are central chemoreceptors?
Medullary respiratory control center. Monitor CO2 and pH of the CSF
Number of recombinants/total number of offspring
What do myofibrils make up?
What do Myofibers make up?
Z line to z line
What is a sarcomere
Thick and thin filament
I bands only contain
H zone only contains
A bands are
Full lengths of thick filaments in H zone
What generates contraction
Actin and myosin
Length of I band
H zone to H zone
Z lines shorten, Myosin uses ATP, myosin head attaches to myosin binding site on actin. Contraction occurs when myosin head is cocked
4 steps to filament sliding theory
Myosin head binds to actin with ADP and Pi bound, power stroke occurs with myosin head moving to low energy conformation pulls actin toward center of sarcomere. ADP released. Binding of ATP needed necessary for release of actin by myosin. ATP hydrolysis occurs immediately and myosin head is cocked into a high energy confirmation.
What prevents contraction when Ca 2+ is not present
Troponin-Tropomyosin complex in the thin filament
Long protein winding around actin polymer blocking the myosin binding sites