Use the Following Information to Answer the Question

question 9

Multiple Choice

Use the following information to answer the question.
"The native structure of hemoglobin (Hb) comprises of two α and two β subunits, each of which carries a heme group. There appear to be no previous studies that report the in-vitro folding and assembly of Hb from highly unfolded α and β globin in a 'one-pot' reaction. One difficulty that has to be overcome for studies of this kind is the tendency of Hb to aggregate during refolding. This work demonstrates that denaturation of Hb in 40% acetonitrile at pH 10.0 is reversible." (J Am Soc Mass Spectrum 2007, 18, 8-16)
How many heme groups are present in three hemoglobin protein molecules?

• A) 3
• B) 4
• C) 9
• D) 12

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Definitions:

Oceanic Divergent Boundaries

Boundaries between tectonic plates that are moving away from each other, often resulting in the formation of new oceanic crust through volcanic activity.

Conveyor-belt Manner

A way of describing the movement and recycling of materials, often used in the context of plate tectonics and ocean currents.

Asthenosphere

A region of the Earth's upper mantle that lies just below the lithosphere and is involved in plate tectonic movements due to its plasticity.

Mid-ocean Ridges

Underwater mountain ranges formed by the upwelling of magma where tectonic plates are diverging, key sites of seafloor spreading.