Monday 21st October 2024
Pearson BTEC Level 3 National Extended Diploma in
Applied Science
Shaafee uddin
Student id: 20527763
Unit 11: Genetics & Genetic Engineering
Learning Aim (A): Understand the structure and function of nucleic acids in
order to describe gene expression and the process of protein synthesis.
Structure & function of nucleic
acids
Scenario:
I am applying to do work experience in a molecular biology laboratory. As part of the
application process, I have been asked to produce an illustrative report to demonstrate
my understanding of DNA, RNA, and protein synthesis and the consequences of error
occurring in protein synthesis.
Nucleic acids:
Nucleic acids are universal, found in all living organisms on Earth—from prokaryotic and
eukaryotic cells to viruses (akaryotes). Both DNA (Deoxyribonucleic acid) and RNA
(Ribonucleic acid) are polymers, composed of monomers called nucleotides; (See Figure
1.01). Nucleic acids are polynucleotides (See Figure 1.02).
Nucleotides are joined together by condensation reactions. DNA and RNA are the most
common nucleic acids in nature and form the foundation of life on Earth, storing the
information necessary to create proteins, which enable cellular functions essential for
survival and reproduction. However, beyond natural nucleic acids, scientists have also
developed artificial nucleic acids that mimic these natural molecules, holding potential to
serve similar functions. These artificial molecules are being explored as the basis for an
“artificial life form” that could maintain and interpret synthetic nucleic acid information,
creating proteins to sustain itself.
Figure 1.01- Ribose & Deoxyribose sugars
, Figure 1.02- Three nucleotides joined together. The
sugars (orange) and phosphate groups (red), form
the backbone. The nitrogenous bases are shown in
(green)
There are 5 different nucleotide bases:
Adenine (A)
Guanine (G)
Both of these bases have a double ring structure. These are purines
Cytosine (C)
Thymine (T)
Uracil (U)
These bases have a single ring structure. These are pyrimidines
DNA contains the bases A, T, G, and C; RNA contains the bases A, U, G, and C. (See
figure 1.03)
Figure 1.03- Purine & Pyrimidine
nucleotide bases
, Name Description (function, structure,
location & main features)
DNA (Deoxyribonucleic acid) DNA (Deoxyribonucleic acid) is the nucleic
acid fundamental to life on Earth, present
in nearly all living organisms. In
prokaryotic cells (bacteria), DNA exists as
a single circular chromosome lying freely
in the cytoplasm, alongside smaller DNA
loops known as plasmids. In eukaryotic
cells, most DNA is enclosed within the
nucleus and organised into multiple linear
chromosomes, each containing a long
DNA molecule closely associated with
histone proteins. Additionally, eukaryotic
cells have DNA in their mitochondria, and
Figure 1.04- Hydrogen bonding between in some plant and algal cells, DNA is also
bases present in chloroplasts. The primary
function of DNA is to carry genetic
information—the genetic code containing
instructions necessary for an organism to
grow, reproduce, and function, which is
passed from parents to offspring during
fertilisation.
The DNA molecule is structured as a double
helix, composed of two long strands arranged
in a spiral. Each DNA molecule has two
backbone chains of deoxyribose sugars
and phosphate groups running in opposite
directions, or anti-parallel. Between these
backbones are nitrogenous base pairs
joined by hydrogen (H) bonds, forming the
“rungs” of the ladder. Each pair joins a
purine base with a pyrimidine base,
keeping the "rungs" uniform in
Figure 1.05- Double helix structure of size. Adenine (A) pairs with Thymine (T) via
DNA, showing the directions of 3’ to 5’ two hydrogen bonds, and Guanine
(G) pairs with Cytosine (C) via three
hydrogen bonds. This specific pairing is
known as complementary base pairing (see
Figure 1.04).
Nucleotides, named for the nitrogenous
bases they contain, derive much of their
structure and bonding properties from the
deoxyribose molecule. This molecule
features a five-carbon ring, where each
carbon is numbered with a prime symbol
('). The 5' carbon, particularly significant
as the site of phosphate group
attachment, marks the 5' end of the
nucleotide. Opposite it, the 3' carbon
lacks a phosphate group, representing the
nucleotide’s 3' end. When nucleotides link
Pearson BTEC Level 3 National Extended Diploma in
Applied Science
Shaafee uddin
Student id: 20527763
Unit 11: Genetics & Genetic Engineering
Learning Aim (A): Understand the structure and function of nucleic acids in
order to describe gene expression and the process of protein synthesis.
Structure & function of nucleic
acids
Scenario:
I am applying to do work experience in a molecular biology laboratory. As part of the
application process, I have been asked to produce an illustrative report to demonstrate
my understanding of DNA, RNA, and protein synthesis and the consequences of error
occurring in protein synthesis.
Nucleic acids:
Nucleic acids are universal, found in all living organisms on Earth—from prokaryotic and
eukaryotic cells to viruses (akaryotes). Both DNA (Deoxyribonucleic acid) and RNA
(Ribonucleic acid) are polymers, composed of monomers called nucleotides; (See Figure
1.01). Nucleic acids are polynucleotides (See Figure 1.02).
Nucleotides are joined together by condensation reactions. DNA and RNA are the most
common nucleic acids in nature and form the foundation of life on Earth, storing the
information necessary to create proteins, which enable cellular functions essential for
survival and reproduction. However, beyond natural nucleic acids, scientists have also
developed artificial nucleic acids that mimic these natural molecules, holding potential to
serve similar functions. These artificial molecules are being explored as the basis for an
“artificial life form” that could maintain and interpret synthetic nucleic acid information,
creating proteins to sustain itself.
Figure 1.01- Ribose & Deoxyribose sugars
, Figure 1.02- Three nucleotides joined together. The
sugars (orange) and phosphate groups (red), form
the backbone. The nitrogenous bases are shown in
(green)
There are 5 different nucleotide bases:
Adenine (A)
Guanine (G)
Both of these bases have a double ring structure. These are purines
Cytosine (C)
Thymine (T)
Uracil (U)
These bases have a single ring structure. These are pyrimidines
DNA contains the bases A, T, G, and C; RNA contains the bases A, U, G, and C. (See
figure 1.03)
Figure 1.03- Purine & Pyrimidine
nucleotide bases
, Name Description (function, structure,
location & main features)
DNA (Deoxyribonucleic acid) DNA (Deoxyribonucleic acid) is the nucleic
acid fundamental to life on Earth, present
in nearly all living organisms. In
prokaryotic cells (bacteria), DNA exists as
a single circular chromosome lying freely
in the cytoplasm, alongside smaller DNA
loops known as plasmids. In eukaryotic
cells, most DNA is enclosed within the
nucleus and organised into multiple linear
chromosomes, each containing a long
DNA molecule closely associated with
histone proteins. Additionally, eukaryotic
cells have DNA in their mitochondria, and
Figure 1.04- Hydrogen bonding between in some plant and algal cells, DNA is also
bases present in chloroplasts. The primary
function of DNA is to carry genetic
information—the genetic code containing
instructions necessary for an organism to
grow, reproduce, and function, which is
passed from parents to offspring during
fertilisation.
The DNA molecule is structured as a double
helix, composed of two long strands arranged
in a spiral. Each DNA molecule has two
backbone chains of deoxyribose sugars
and phosphate groups running in opposite
directions, or anti-parallel. Between these
backbones are nitrogenous base pairs
joined by hydrogen (H) bonds, forming the
“rungs” of the ladder. Each pair joins a
purine base with a pyrimidine base,
keeping the "rungs" uniform in
Figure 1.05- Double helix structure of size. Adenine (A) pairs with Thymine (T) via
DNA, showing the directions of 3’ to 5’ two hydrogen bonds, and Guanine
(G) pairs with Cytosine (C) via three
hydrogen bonds. This specific pairing is
known as complementary base pairing (see
Figure 1.04).
Nucleotides, named for the nitrogenous
bases they contain, derive much of their
structure and bonding properties from the
deoxyribose molecule. This molecule
features a five-carbon ring, where each
carbon is numbered with a prime symbol
('). The 5' carbon, particularly significant
as the site of phosphate group
attachment, marks the 5' end of the
nucleotide. Opposite it, the 3' carbon
lacks a phosphate group, representing the
nucleotide’s 3' end. When nucleotides link
