Question

2. Match the following structural characteristics with either MHC class I (I), class II (II), or both (I & II).

a. Contains ��2-microglobulin ________
b. Contains two transmembrane domains ________
c. Binds 8-10 amino acid peptides ________
d. Contains two heavy chains ________
e. Has closed ends on the peptide binding groove ________

Answer 1

MHC class I molecules contain β2-microglobulin, bind 8-10 amino acid peptides, and have closed ends on their peptide-binding groove, while MHC class II molecules contain two transmembrane domains and two heavy chains.

Step-by-step explanation:

Matching the structural characteristics to either MHC class I, class II, or both involves understanding the differences in their molecular structures. Here are the matches:

a. Contains β2-microglobulin I

b. Contains two transmembrane domains II

c. Binds 8-10 amino acid peptides I

d. Contains two heavy chains II

e. Has closed ends on the peptide binding groove I

MHC I molecules are present on the surface of all nucleated cells and consist of a larger α subunit and a smaller β2 microglobulin. The peptide binding groove of MHC I has closed ends and can bind peptides that are 8-10 amino acids long. In contrast, MHC II molecules are found on specific antigen-presenting cells such as macrophages, dendritic cells, and B cells and are composed of two chains (a and β) that have two transmembrane domains, suggesting that each chain crosses the cell membrane. The antibody structure bears a resemblance to the extracellular component of MHC molecules.