4.2.2 The Structure of RNA Flashcards
Like DNA, the nucleic acid RNA (ribonucleic acid) is a
polynucleotide
Like DNA, the nucleic acid RNA (ribonucleic acid) is a polynucleotide, it is made up of
many nucleotides linked together in a long chain
Like DNA, RNA nucleotides contain the nitrogenous bases
adenine (A), guanine (G) and cytosine (C)
Unlike DNA, RNA nucleotides never contain the nitrogenous base
thymine (T)
Unlike DNA, RNA nucleotides never contain the nitrogenous base thymine (T), in place of this they contain the nitrogenous base
uracil (U)
Unlike DNA, RNA nucleotides contain the pentose sugar
ribose (instead of deoxyribose)
RNA nucleotide
DNA nucleotide
Unlike DNA, RNA molecules are only made up of one
polynucleotide strand (they are single-stranded)
Each RNA polynucleotide strand is made up of
alternating ribose sugars and phosphate groups linked together
Each RNA polynucleotide strand is made up of alternating ribose sugars and phosphate groups linked together, with the nitrogenous bases of each nucleotide
projecting out sideways from the single-stranded RNA molecule
The sugar-phosphate bonds (between different nucleotides in the same strand) are covalent bonds known as
phosphodiester bonds
These bonds form what is known as
the sugar-phosphate backbone of the RNA polynucleotide strand
The phosphodiester bonds link the
5-carbon of one ribose sugar molecule
The phosphodiester bonds link the 5-carbon of one ribose sugar molecule to
the phosphate group from the same nucleotide
The phosphodiester bonds link the 5-carbon of one ribose sugar molecule to the phosphate group from the same nucleotide, which is itself linked by
another phosphodiester bond
The phosphodiester bonds link the 5-carbon of one ribose sugar molecule to the phosphate group from the same nucleotide, which is itself linked by another phosphodiester bond to
the 3-carbon of the ribose sugar molecule
The phosphodiester bonds link the 5-carbon of one ribose sugar molecule to the phosphate group from the same nucleotide, which is itself linked by another phosphodiester bond to the 3-carbon of the ribose sugar molecule of
the next nucleotide in the strand
An example of an RNA molecule is
An example of an RNA molecule is
An example of an RNA molecule is messenger RNA (mRNA), which is
the transcript copy of a gene
An example of an RNA molecule is messenger RNA (mRNA), which is the transcript copy of a gene that
encodes a specific polypeptide.
An example of an RNA molecule is messenger RNA (mRNA), which is the transcript copy of a gene that encodes a specific polypeptide, two other examples are
transfer RNA (tRNA) and ribosomal RNA (rRNA)
mRNA is a single-stranded
molecule
mRNA is made up of
a sugar-phosphate backbone and exposed unpaired bases
