Select all that apply.

Enzymes .

A: are not required to sustain the life of an organism

B: act as catalysts in chemical reactions of cells

C: interact with specific substrates like a lock and key

D: can lower the required activation energy for reactions in living organisms

hey buddy I think option A Is incorrect else all three are perfect!

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.