Why is it possible for bacteria to make a human protein, such as insulin?

Why is it possible for bacteria to make a human protein, such as insulin?

• A. The DNA structure and code, and the transcription/translation machinery, are the same across all living organisms.
• B. Bacteria membranes identical to human.
• C. Plasmids can alter the human DNA to match bacteria.
• D. All genes universal.

Answer: (A)

The key idea is that the genetic code and the basic machinery that read and build proteins are conserved across organisms. The same codons in mRNA specify the same amino acids in both humans and bacteria, so a gene from one organism can be translated into a protein by the other, provided it’s set up in a way the bacterial system can understand. In practice, scientists take the human gene that encodes insulin and insert it into a bacterial plasmid that has a bacterial promoter and other regulatory elements. They also use a version of the gene without introns (a coding sequence) because bacterial cells can’t splice introns like human cells do. The bacteria then transcribe the gene into messenger RNA and translate that RNA into insulin using their own transcription and translation machinery, producing the human protein. Other statements aren’t the reason this works. Bacterial membranes aren’t identical to human membranes, and that difference isn’t what allows insulin production. Plasmids don’t alter human DNA to match bacteria; they’re tools to introduce human genes into bacteria. And while the genetic code is universal, not all genes are universal in sequence or regulation, so the ability to make a human protein in bacteria relies on the shared code and machinery, plus proper gene engineering.

The key idea is that the genetic code and the basic machinery that read and build proteins are conserved across organisms. The same codons in mRNA specify the same amino acids in both humans and bacteria, so a gene from one organism can be translated into a protein by the other, provided it’s set up in a way the bacterial system can understand.

In practice, scientists take the human gene that encodes insulin and insert it into a bacterial plasmid that has a bacterial promoter and other regulatory elements. They also use a version of the gene without introns (a coding sequence) because bacterial cells can’t splice introns like human cells do. The bacteria then transcribe the gene into messenger RNA and translate that RNA into insulin using their own transcription and translation machinery, producing the human protein.

Other statements aren’t the reason this works. Bacterial membranes aren’t identical to human membranes, and that difference isn’t what allows insulin production. Plasmids don’t alter human DNA to match bacteria; they’re tools to introduce human genes into bacteria. And while the genetic code is universal, not all genes are universal in sequence or regulation, so the ability to make a human protein in bacteria relies on the shared code and machinery, plus proper gene engineering.