1. Phosphate Group
DNA & RNA
Nitrogen Base
Pentose Sugar
DNA & RNA are the 2 types of nucleic acid.
They are made up of structures: the pentose
sugar, phosphate group and the nitrogen
base.

2. Keywords:
• DNA
• Deoxyribonucleic acid.
• RNA (mRNA, tRNA)
• Ribonucleic acid (mRNA stands for messenger RNA, tRNA
stands for transfer RNA).
• Nucleotide
• A compound containing a pentose sugar, phosphate group
and a nitrogen base.
• Polynucleotide
• A polymer made up of many nucleotides.
• Pentose Sugar
• A sugar that contains 5 carbon atoms.
• Phosphate Group
• A group important in energy transfer.

3. Keywords:
• Nitrogenous or Nitrogen-containing Base
• A base that contains nitrogen and is necessary for protein
synthesis.
• Semi-conservative
• When a or chromatid is kept from the mother and its
joining chromatid is made from the free nucleotides in the
nucleus.
• Codon
• A series of 3 adjacent bases that code for a certain amino
acid.
• Anticodon
• A series of 3 adjacent bases that correspond through
complementary base pairing to the codon on a RNA strand.
• Triplet
• A series of 3 adjacent bases on a DNA strand.

4. Nucleotides and Polynucleotides
Nucleotides are a small cluster of molecules that build up a strand of
DNA and RNA. Nucleotides can have 5 different bases and 2 different
sugars, however this changes whether if they are DNA or RNA.
There are 2 groups of bases and 2 groups of sugars.
• Pyrimidine
• Thymine
• Cytosine
• Uracil (only in RNA, replaces Thymine)
• Purine
• Adenine
• Guanine
There are two sugars, deoxyribose and ribose, the previous is in
DNA (deoxyribonucleic acid) and the latter in RNA (ribonucleic acid).

5. Complementary-base Pairing
DNA and RNA structure uses complementary-base pairing
to pair the bases perfectly, such as adenine on one end
and thymine on the other, similar to guanine being on one
side and cytosine being on the other as such:
Don’t forget that
A to T only have
2 hydrogen Cytosine Guanine
bonds while C to
G have 3!
Adenine Thymine

6. Transcription
Transcription is the process in which DNA uses mRNA to
make a code in which they will collect amino acids via the
ribosome and create a protein, this is succeeded by
translation.
The process starts with the DNA breaking up
to unveil a strand in which it houses a code
for a certain amino acid. Then through RNA
polymerase, a mRNA strand is
created, nucleotide by nucleotide with
complimentary base pairing, Uracil replaces
Thymine as you can see in the image. And
then the mRNA leaves the nucleus to
proceed to translation.

7. Translation
Translation takes place in the cytoplasm, it is when the mRNA
strand that was transcribed then goes to a ribosome to enter the
translation phase. The ribosome collects tRNA which are made
up of 3 adjacent bases that compliment the bases on the mRNA
strand. These 3 bases create an amino acid which is then held
onto the other amino acids being created by a peptide bond.
Remember that mRNA
always ends with a ‘stop’
codon!
The codon is always one of
three:
• UAG
• UAA
• UGA

8. This diagram shows how nucleotides
DNA Replication free in the nucleus bind with the DNA
to create a second strand.
The two
phosphates are
left free to bind
with another
nucleotide to bind
with another DNA
strand.

9. DNA Replication ~ pt.2
DNA replication is a simple process, it takes place during
the interphase after a cell has divided, due to the small
number of chromosomes and only chromatids, nucleotides
bind with the DNA chromatid and start its evolution into a
chromosome.
A certain enzyme, DNA polymerase, will act upon the
nucleotides to cause this process. And as told, DNA is a
polynucleotide, with the smaller subunits being the
nucleotides.
And from this we know that DNA is semi-conservative, in
that it keeps one strand from the original cell and the other
being fully created from nucleotides in the nucleus.

10. DNA Replication ~ diagram
The strands were
once the
same, identical in
every way. While
now they are 2
different strands.
We say they are
semi-
conservative.

11. Questions?

12. Thank you!