In the electron transport chain, electrons move through the cytochromes in the following order: b566, b562, c1, c, a, and a3 (see Figure 16-19). The various cytochromes have slightly different heme groups and axial ligands, which generate different environments for the Fe ion (Figure 16-21).
On average, a woman has her period from three to seven days and the average woman menstruates from age 13 until age 51. That means the average woman endures some 456 total periods over 38 years, or roughly 2,280 days with her period -- 6.25 years of her life. Midol. You can only take up to six caplets a day, and cramps usually persist for two days. There are 40 caplets per package of Midol, which costs $8.99 at Walgreens.
Many women have a cycle that lasts 28 days. Some women may have cycles as long as 45 days. The cycle includes not just your period, but the rise and fall of hormones and other body changes that take place over the month. To see what happens on each day of your menstrual cycle check out our cool guide to your period. Keep in mind that your periods may not be regular at first. You may have two in one month, or have a month without a period at all. Also, at first your period may last just a couple of days in some months and up to a week in other months. Periods will become more regular in time.