alleryStart learning →Where on the haemoglobin molecule does carbon dioxide bind?
ATo the iron atom at the centre of each heme
BTo the same site that binds oxygen molecules
CTo the phospholipid of the red cell membrane
DTo amino acid groups on the globin portions
Answer & Solution
Correct answer: D. To amino acid groups on the globin portions
1. Oxygen binds the iron held within heme.
2. Carbon dioxide does not bind iron at all.
3. It binds amino acid groups on the globin portions of the molecule, forming carbaminohaemoglobin.
4. Because the two gases use different sites, haemoglobin can carry both at once, which is why the first two options are wrong.
_Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 22 "The Respiratory System", section 22.5 Transport of Gases_
Keep practising The Respiratory System
Browse all The Respiratory System questions for NEET PG, or explore more Physiology topics.
Related questions
Why is survival low for a baby born before 26 weeks?By how much has surfactant therapy reduced death from respiratory distress syndrome?What proportions of preterm infants are quoted as developing respiratory distress syndromeWhat happens to the fluid left in the lungs after delivery?How soon after birth does the first inhalation occur?What does the fetus move in and out during fetal breathing movements?Around which week do fetal breathing movements begin?When does a full complement of functional alveoli appear?