Question: The α-keratin consists of: 
 Options:  <1> Two dextrorotative α-propellers coiled to form a left-handed helix. <2> Two dextrorotary propellers coiled to form a left-handed helix. <3> Two levorotylar helices coiled to form a levorotatory helix. <4> Two levógiras α helices coiled to form a dextrorotatory helix. <5> One helix α levorotatory and one dextrorotatory coiled to form a levorotatory helix.
1