NUCLEIC ACIDS
2.1 - 2.4.
2.1. Structure of RNA and DNA
Nucleic acids are a group of very important molecules. They include ribonucleic
acid (RNA) and deoxyribose nucleic acid (DNA). DNA carries genetic
information and passes on the features of organisms from one generation to
the next.
● 4th biological molecule.
● Polymer.
● Individual units are called a mononucleotide.
● DNA - deoxyribonucleic acid (oxygen, carbon, hydrogen, phosphorus,
nitrogen, sugar), RNA - ribonucleic acid. PHONCS
Nucleotide structure
Individual nucleotides are made up of 3 components:
1. A pentose sugar (so called because it has 5 carbon atoms).
2. A phosphate group.
3. A nitrogen-containing (nitrogenous) base. These are adenine A, thymine
T, guanine G and cytosine C.
● The pentose sugar, phosphate group and organic base are joined as a
result of condensation reactions, to form a MONOnucleotide.
,● Two mononucleotides may be joined as a result of a condensation
reaction between the deoxyribose sugar of one mononucleotide and the
phosphate group of another. The bond formed between them is called a
phosphodiester bond.
● This continued linking of mononucleotides in this way forms a long chain
called a polynucleotide.
● In addition to DNA and RNA, other biologically important molecules also
contain nucleotides.
, Bonding:
● The nitrogenous base and deoxyribose sugar join with a glycosidic bond.
● The phosphate and deoxyribose sugar join with an ester bond.
● Both require a condensation reaction to occur.
Ribonucleic acid (RNA) structure
● Ribonucleic acid is a polymer made up of nucleotides.
● It is a single, relatively short, polynucleotide chain in which the pentose
sugar is always ribose.
● The organic bases are: adenine, uracil, guanine, cytosine.
2.1 - 2.4.
2.1. Structure of RNA and DNA
Nucleic acids are a group of very important molecules. They include ribonucleic
acid (RNA) and deoxyribose nucleic acid (DNA). DNA carries genetic
information and passes on the features of organisms from one generation to
the next.
● 4th biological molecule.
● Polymer.
● Individual units are called a mononucleotide.
● DNA - deoxyribonucleic acid (oxygen, carbon, hydrogen, phosphorus,
nitrogen, sugar), RNA - ribonucleic acid. PHONCS
Nucleotide structure
Individual nucleotides are made up of 3 components:
1. A pentose sugar (so called because it has 5 carbon atoms).
2. A phosphate group.
3. A nitrogen-containing (nitrogenous) base. These are adenine A, thymine
T, guanine G and cytosine C.
● The pentose sugar, phosphate group and organic base are joined as a
result of condensation reactions, to form a MONOnucleotide.
,● Two mononucleotides may be joined as a result of a condensation
reaction between the deoxyribose sugar of one mononucleotide and the
phosphate group of another. The bond formed between them is called a
phosphodiester bond.
● This continued linking of mononucleotides in this way forms a long chain
called a polynucleotide.
● In addition to DNA and RNA, other biologically important molecules also
contain nucleotides.
, Bonding:
● The nitrogenous base and deoxyribose sugar join with a glycosidic bond.
● The phosphate and deoxyribose sugar join with an ester bond.
● Both require a condensation reaction to occur.
Ribonucleic acid (RNA) structure
● Ribonucleic acid is a polymer made up of nucleotides.
● It is a single, relatively short, polynucleotide chain in which the pentose
sugar is always ribose.
● The organic bases are: adenine, uracil, guanine, cytosine.
