"The Native Structure of H[a]emoglobin (Hb) Comprises of Two α

question 13

Multiple Choice

"The native structure of h[a]emoglobin (Hb) comprises of two α and two β subunits, each of which carries a h[a]eme 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)
-Haemoglobin, when subjected to 40% acetonitrile at pH 10.0, loses its quaternary structure, which means the ________.

• A) four α and β polypeptides dissociate
• B) peptide bonds between amino acids break
• C) α and β polypeptides lose their 3-D structure
• D) four α and β polypeptides dissociate, peptide bonds between amino acids, and α and β polypeptides lose their 3-D structure

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Definitions:

Perceptual Narrowing

A process in which infants lose their apparently innate abilities to detect certain sensory features because those features do not occur very often in their environments.

Experience-Dependent

A term describing traits or abilities that develop or change in response to the environment and specific experiences.

Rosenzweig

Refers to Saul Rosenzweig, a psychologist known for his work on frustration and aggression, and for developing the Rosenzweig Picture-Frustration Study.

Synaptic Connections

The points of contact where signals are transmitted between neurons, enabling communication within the nervous system.