An SDS lysate of red blood cells was submitted to SDS polyacrylamide gel electrophoresis. The sample revealed a major band with a molecular weight of approximately 17,000. What protein do you think is responsible for this band?

Based on the molecular weight given - 17,000, the protein in the red blood cells is Haemoglobin A (Hb A).

Explanation:

The technique used for protein molecule separation based on their molecular size of protein in molecular biology study along with a reference protein marker for the identification of exact unknown protein size is known as SDS polyacrylamide gel electrophoresis. During the separation method of protein, DNA and RNA,  etc, Sodium dodecyl sulfate is a synthetic organic compound used as a surfactant in the lysis solution.

Based on the molecular weight given - 17,000, the protein in the red blood cells is Haemoglobin A (Hb A). Its function is to carry oxygen from the respiratory organs to the rest of the body and tissues. Hb A is found in the form of a tetramer, that is, it contains four subunits proteins consisting of two alpha and two beta subunits each consist of 141 & 146 amino acid residues. Each subunit has a molecular size of about 16000 daltons approx and they are structurally similar and have the same size.