Structure Of Ribonucleic Acid Flashcards
How comes mRNA can leave the nucleus but the DNA cannot?
The mRNA is small enough to move through the nuclear pores
What sort of RNA transfers the DNA code from the nucleus to the cytoplasm?
Messenger RNA (mRNA)
What is the genetic code?
A sequence of nucleotide bases
What is a codon?
A sequence of three bases on mRNA that code for a single amino acid
What are stop codons?
Codons that mark the end of a polypeptide chain and do not code for an amino acid
What are the three key features of the genetic code?
It is degenerate, Non-overlapping and is a universal code
What is the degenerate code?
This means that most amino acids have more than one codon
What is meant by non-overlapping?
Each base is only read one
Explain the idea of a universal code?
The same codons code for the same amino acids in all organisms
What is RNA?
A polymer made up of repeating mononucleotide sub-units
What type of sugar is found in RNA?
A pentose sugar (Ribose)
What are the four bases found in RNA?
Adenine, Guanine, Cytosine and Uracil
What else is present in RNA?
A phosphate group
Other than mRNA what is another type of RNA?
Transfer RNA (tRNA)
Describe the shape of tRNA
A single stranded chain folded into a clover-leaf shape, with one end of the chain extending beyond the other
