A"mystery molecule" was isolated in a laboratory and scientists found that the molecule readily crossed artificial membranes. which of the following molecules can be ruled out as the "mystery molecule"? a. nitrogen b. oxygen c. carbon dioxide d. calcium chloride e. water

Answer:       D. calcium chloride

Calcium chloride molecules can be ruled out as the mystery molecule

Explanation:

Artificial membranes are also called as the synthetic membranes. It is created synthetically for the special separation purpose in the laboratory.

It is used to separate large molecules like solid particles and big biological molecules like protein, DNA.

They are produced from organic materials. Calcium chloride contains the chloride ion and calcium ion, as the chloride ion easily passes the artificial membrane so we can term calcium chloride as the mystery membrane that passes the artificial membrane easily.

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.