P450scc or cholesterol side chain cleavage enzyme is an enzyme that converts cholesterol into pregnenolone (the precursor for steroids). The kinds of steroid hormones are mineralocorticoids (i.e. aldosterone) glucocorticoids (i.e. cortisol), and sex steroids (i.e. testosterone, estrogen). In the event where P450scc is blocked, then there will be no production of mineralocorticoids, glucocorticoids, and sex steroids. There will be no production of aldosterone, cortisol, estradiol, testosterone, and progesterone. This disease is called Lipoid Congenital Adrenal Hyperplasia.
Answer:
Bacteria do not possess the tendency to withdraw sequences of introns from a gene, thus, if the gene for the human growth hormone were transcribed, it would translate into a non-functional protein.
When the expression of a gene takes place in eukaryotes, the budding mRNA comprising introns are removed consequently at the time of post-translational processing to produce mature mRNA. Also, the human growth hormone is produced by the pituitary gland in the form of a pre-hormone comprising a leader peptide of about 20 amino acids in length, which need to get removed post-translationally to produce a mature functional protein.
Bacteria do not possess the biochemical machinery either to effectively withdraw the leader peptide after translation or to splice out the introns. Thus, when an unchanged human growth hormone is cloned, the bacteria cannot produce the functional human growth hormone.
The big idea to remember is that mitosis is the simple duplication of a cell and all of its parts. It duplicates its DNA and the two new cells (daughter cells) have the same pieces and genetic code. Two identical copies come from one original. Start with one; get two that are the same. You get the idea.
So it is the very last stage!
