The second carbon is connected to the amino group. Amino means there is an NH 2 group bonded to the carbon atom. In the image, you see a + and a -. Those positive and negative signs are there because, in amino acids, one hydrogen atom moves to the other end of the molecule. An extra H gives you a positive charge.
Ranges of normal estrogen levels are measured in parts pg/ml of estradiol. In normal reproductive age women, during the menstrual cycle, estradiol levels range from 50-400 pg/ml. The actual normal level of estrogen varies during different parts of the menstrual cycle. In menopause, the general range may be 10-20 pg/ml.
Estradiol. Estrogen is the predominant female hormone; estradiol is the predominant form of estrogen produced in the ovaries. Normal estrogen levels, according to Fertility Plus hormone charts, on days two to three of the menstrual cycle are 25 to 75 picograms per milliliter (pg/ml).