Question

i seriously cannot figure this one out, im on attempt 13.. please help!

Resources Ex Give Up? Hint Check Answ on 7 of 14 > Attempt 1 One of the major classes of antibody molecules is immunoglobulin G (IgG). Treating IgG with papain protease cleaves the IgG molecule into two fragments, Fe and Fab. Classify each description that applies to Fc fragments, Fab fragments, or both types of fragments. Fe fragments Fab fragments Both Fe and Fab fragments crystallize readily bind antigens contain variable domains made of only heavy chain polypeptides contain constant domains recognized by macrophage surface receptors stabilized by disulfide bonds often undergo conformational changes made of light chain and heavy chain polypeptides Answer Bank made of only light chain polypeptides

Answer 1

ANSWER:

	Fc fragment	Fab fragment	Both Fc and Fab fragments
Bind antigens		x
Contain constant domains			x
Contain variable domains		x
Crystallize readily	x
Made of light chain and heavy chain polypeptides		x
Made only of heavy chain polypeptides	x
Made only of light chain polypeptides
Often undergo conformational changes		x
Recognized by macrophage surface receptors	x
Stabilized by disulfide bonds			x

• The Fc fragment means crystallizable fragment. The Fc contains only constant domain from the heavy chain. The polypeptide chains are stabilized by disulfide bonds
• The Fab fragment means fragment antigen-binding. The Fab contains both constant and variable domains of heavy and light chains of polypeptides. The polypeptide chains are linked by disulfide bonds
• Fc receptors are found on surface of several type-cells, including the macrophages.
• Onlly Fab has conformational changes that are induced by antigen binding