Biological Trends Improvement Flashcards
Stretch of lung
Inhibits inspiration
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
Recombination Frequency
Number of recombinants/total number of offspring
What do myofibrils make up?
Myofibers
What do Myofibers make up?
Muscle fassicles
Sarcomere length
Z line to z line
Actin forms
Thin filaments
Myosin forms
Thick filaments
What is a sarcomere
Thick and thin filament
I bands only contain
Thin filaments
H zone only contains
Thick filaments
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
During contraction
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
Tropomyosin
Long protein winding around actin polymer blocking the myosin binding sites
Troponin
Globular protein bound to Tropomyosin that can bind Ca2+. When undergoing conformational change it is bound to Ca that moves Tropomyosin so that myosin binding site exposed
