Zoology 484 M.P.Wenderoth

November 14, 1997

Readings: Randall Chapter 13 pp. 519-523

Transport of Oxygen in Circulatory System

dissolved in plasma

bound to respiratory pigment

Respiratory pigmentation

hemoglobin ----iron-------red

hemocyanin----copper----blue

chlorocruorin---iron------green

hemerythrin---- iron-------red

Hemoglobin

tetramer 4 globin subunits each with a heme

monomer--myoglobin

Rate of transfer of Gas

surface area

thickness of membrane

pressure gradient

Oxygen pressure gradient in the alveolus

in equilibrium with plasma of blood

Hemoglobin increases transfer of oxygen and maintains gradient

Oxygen dissociation curve of Hemoglobin and myoglobin

reversible binding to oxygen

subunit cooperativity

oxygen affinity function of hemoglobin protein

oxygen binding a function of P O2

Oxygen dissociation curves for hemoglobin from different animals

function of size of animal and

function of activity level of animal

function of living environment

Oxygen affinity-- how tightly oxygen binds to hemoglobin or how easily it is given off

low affinity--[hi P 50] == favors release at tissues

High affinity--[lo P50] == favors binding at the lungs