Exam 3: Ch 13 Notes Flashcards
gas exchange challenges
SA:Vol ratio
need O2 for cellular respiration
need to dump O2 from cellular respiration
does an amoeba need gills?
no, it has a high surface area to volume ratio
atmosphere makeup
78% N2
21% O2
9% other
0.3% CO2
gas exchange must meet ______ specific demands
tissue specific demands
problem… where do you live?
sea level
altitude
in water
in the water, O2 is only available…
1/30th of atmosphere
dissolves from atmosphere
produced from photosynthesis
water in diff salinities/temps
fresh
salt @ 30 degrees 4.34 ml O2/L
salt @ 15 degrees 5.75 ml O2/L
water has layers
salinity and temp restrict O2 movement
less diffusion
how to max diffusion
large surface area
minimize distance to diffuse
maximize concentration gradient –> remove boundary layers w/ blood flow
hemoglobin increases
carrying capacity of blood
how do we increase carrying capacity more
RBC increase production of EPO
plasma
doping: 1 pt of blood –> spin –> give RBC back “treacle” viscous blood
ice fish don’t have a _______ pigment
respiratory
low temp –> more O2 dissolved
temp conformer so low temp = low metabolic rate (less O2 demand)
increased blood volume and cardiac output
hemoglobin structure
2 dimers a,b a2,b2 4 subunits each binds O2
Hb + O2 vs. Hb by itself
oxyhemoglobin; deoxyhemoglobin
Hb is better at binding..
carbon monoxide 200x
displaces O2
no detection system
sickle cell anemia
Hb clumps, distorts RBC
lower O2 carrying capacity
RBC get stuck in capillaries
resistance to malaria
myoglobin
muscles 1 subunit
no subunit cooperativity
not as well tunes
Hb + O2 cooperative binding
sigmoidal curve
good at binding O2 in regions w/ high pO2
bad at binding O2 in regions w/ low pO2
this allows Hb to release O2 in tissues w/ low O2
how is Hb tuned
more release at partial pressures that are experienced in metabolic tissues
Bohr effect
more acidic conditions = less O2 bound to Hb
ex. 30mmHg pH 7.4 = 30% saturation
pH 7.2 = 15% saturation
what conditions wound you find in exercising muscle
more acidic
less O2, more CO2
higher temp
all cause Hb to release more O2
Hb has a changing affinity for O2 depending on
conditions of surrounding tissue
developmental changes of Hb
different Hbs
fetal Hb binds O2 better, better transport of maternal O2 –> fetus
CO2 transport
oxygenated blood has less CO2 carrying capacity
deoxygenated blood has more CO2 carrying capacity
CO2 transport in peruvian, tibetan, and kenyan people
lower CO2 binding Hb
increased RBC, Hb, NO
more heart capacity
andean populations
increased RBC + Hb
many unsaturated RBC
viscous blood
himalayan population consists of which two groups
tibet and nepal
himalayan populations CO2 transport
O2 sat lower than sea level
high levels of NO (240x)
vasodilator, blood vessel relaxation in lungs (wider for blood flow)
himalayan populations breathe…
deeper and faster
EPAS1 - monitors O2 levels
prevent overproduction of RBC
kenyan populations
increased rate of O2 transfer from alveoli to blood
Hb levels and O2 saturation same as sea level
major things that Hb binds
O2
H+
CO2
both __ and __ compete w/ O2 for Hb binding
H+, CO2
CO2 to HCO3- and H2CO3 ratios
CO2:H2CO2 1000:1
CO2:HCO3- 1:20
most CO2 in blood is transported by…
HCO3-
carbamino Hb
protein-NH2 + CO2
can deoxygenated blood carry more CO2 than oxygenated blood?
yes
CO2 pathway in blood
CO2 into blood –> RBC have high carbonic anhydrase –> HCO3- out, Cl- in via band III passive transporter protein
does muscle produce CO2?
yes
Hb deoxygenation binds H+ –> increases HCO3- production to buffer pH change
CO2 in lungs
Hb oxygenation –> H+ release –> HCO3- –> H2CO3 –> released CO2 + H2O
carbonic anhydrase design tweak
in epithelial cells carbonic anhydrase speeds up HCO3- –> CO2
if deoxygenated Hb binds H+, reaction shifts to the _____ and _____ CO2 converted
right, more
reasons for O2 delivery
reduced pO2
H+ competed for Hb binding
CO2 competes to form carbamino Hb
is there gas transfer in cartilage?
no
cystic fibrosis
mutated Cl- transporter, thick mucus not removed
terminal bronchioles are made of
smooth muscle