Moreen Mero BTEC L3 Applied Science Unit 11 Assignment 1 2020/2021
Table 1. Provide a description of the structure, main features and role of each nucleic acid
P1
Structure Features Roles
DNA
DNA has chemical
components, which are DNA is liked the storage of
Deoxyribonucleic acid, is a • four nitrogenous information in the cell, this is
bases(A-adenine/T-
double helix structure, that the main role, also using the
thymine/G-guanine/C-
made up of molecules that cytosine)
genetic code, DNA encode
are called nucleotides. • A deoxyribose(Sugar) amino acid sequence in
• Phosphate proteins
mRNA
It involves with protein
synthesis, as the genetic codes
It contains the genetic codes,
Messenger RNA, it is a (amino acids) are read by the
except for Thymine, it
single stranded copy of ribosomes, and each three
replaced with Uracil, so it will
DNA that could survive letters are converted into
not be the exact same copy of
outside the nucleus. proteins (antibodies) that are
DNA.
used to build and support our
body.
tRNA
Is a small molecule made in The anticodon of tRNA pair
It carries different amino acids,
the nucleus, that with mRNA codon. For
each three bases at the end of
participates in protein example; CCU codon on
tRNA are anticodon, that each
synthesis by pairing its mRNA needs tRNA that has
amino acid has different
anticodon bases with GGA anticodon, this makes
codon.
mRNA codons. protein called PRO.
rRNA (ribosomal ribonucleic
acid) it is a Non-coding The Ribosomal ribonucleic
They move along mRNA
RNA, it carries out protein acid is the RNA component of
molecule, they catalyse the
synthesis in ribosomes. The the ribosomes. They are
gathering of amino acids into a
specific structure of rRNA synthesised in the nucleolus
protein chain.
is called nucleoli, which are that is inside the nucleus.
dense and spherical shaped.
siRNA
siRNA occurs in the RNA
interference pathway (RNAi)
Small interfering RNA, a
Small or short interfering RNA where it interferes with the
non-coding double-stranded
contains about 30-100 “expression” of specific
segment of RNA
nucleotides, and it can only “genes” with complete
molecule.it is about 20-24
target one type of mRNA nucleotide sequences, this
base pairs in length.
happens by degrading the
mRNA after “transcription”
Updated, WHC: June 2017
, Moreen Mero BTEC L3 Applied Science Unit 11 Assignment 1 2020/2021
DNA Deoxyribonucleic Acid
DNA, is the long-term storage of our genetic information, found in
nucleus in our cells, it is a self-replicating material, that is nearly
present in all living organisms. The double helix structure has a
sequence of 4 bases, which encode our genetic information:
Adenine & Guanine are Purines, which are a double pyrimidine ring structure.
Thymine & Cytosine are Pyrimidines, which are a single organic ring structure.
However, on the DNA structure; which is a double helix that looks like a twisted ladder, and the sides of the ladder are
made of those purines and pyrimidines. Each rung(stair) of the ladder is a HYDROGEN BOND between a purine and
a pyrimidine, Always a purine goes with a pyrimidine, this is because of their chemical structure and the distance
between the spirals. Each base has a specific structure as well as a different size, purines are bigger than pyrimidines,
two purines cannot bond together because of their size would be too big and their specific chemical structure will not
allow they to bond, same for pyrimidines. And that’s why purines fit perfectly with pyrimidines, but also at a specific
bonding rules;
Adenine(Purine) bond with Thymine(Pyrimidine) they are joined by hydrogen bonds, Their chemical structure fits
perfectly between them. While
Guanine(Purine) bond with Cytosine(Pyrimidine) for the same reasons, they fit perfectly together in their hydrogen
bonds.
Guanine cannot bond with thymine, even though they are purine and pyrimidine, this is because their chemical structure
does not fit perfectly between them. It is like their structure had been made to fit specifically with each other;
A & T / G & C. However, the bonding between the bases is weak, it can be broken easily.
Updated, WHC: June 2017
