Which molecule translates between genetic information of nucleic acids and proteins?

Question

Which molecule translates between genetic information of nucleic acids and proteins?

Im doing a lab under "Nucleotides, Nucleic Acids and Proteins: Structure and Function" Exercise A: Central Dogma of Molecular Biology

Answer 1

Hello Rosalyn,

 

The Central Dogma of Biology was first formulated by Francis Crick, and it is often summarized as:

"DNA makes RNA and RNA makes protein." When genes, which are encoded as DNA sequences, are expressed, genes are first transcribed into messenger RNA or mRNA. The mRNA is then translated into proteins on ribosomes. Proteins are made out of linear sequences of amino acids, and the mRNA provides a kind of code (the Genetic Code) that determines the amino acid sequence. Three bases of the mRNA form a codon, or the key to what amino acid belongs at that position. Transfer RNA or tRNA carry specific amino acids to the ribosomes where they are added to the end of the protein being synthesized.

 

Francis Crick figured out that 3 bases form a codon because he reasoned that there are 4 "letters" or different bases in RNA (A, U, C, G) and that there are 20 amino acids that make up proteins (most proteins, anyway). 2 bases would give only 4^2=16 possibilities but 3 bases would give 4^3=64 possibilities, the minimum to cover the 20 amino acids. It turns out that there is some redundancy, and there is a start codon and 3 stop codons. You can google "genetic code" to find the key that links the 3-letter RNA code to amino acids. Amazingly, almost every organism on Earth, from bacteria to human beings use the same genetic code. Incidentally, Francis Crick admitted that he coined the phrase "Central Dogma" with a mistaken idea of what dogma meant. He meant "conjecture" or "hypothesis."

Answer 2

Hi Rosalyn,

 

In translation, the main organelle involved is the ribosome. Each one is a site of translation. But to answer your question, the molecule that is involved in translation is most likely tRNA, or transfer RNA. If you have not learned about this molecule, then the follow-up answer would be simply RNA, or ribonucleic acid. tRNA is a specific type of RNA involved in translation, while mRNA, or messenger RNA, is the specific type of RNA involved in transcription.

 

Hope this helps!