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Name: Spendilove Agyemang.ID: 59823.
GENETICS AND GENETIC ENGINEERING.
DNA: A DNA molecule is made up of two linked strands that wind around each other to resemble a
twisted ladder in a helix-like shape. Each strand has a backbone made of alternating sugar
(deoxyribose) and phosphate groups. DNA is also made up of smaller units called nucleotides. Each
nucleotide has three parts: a sugar (ribose), a phosphate molecule, and a nitrogenous base. The
nitrogenous base is the part of the nucleotide that carries genetic information. The bases found in
DNA are four: adenine, cytosine, guanine, and thymine.
Nitrogenous Base: The first component of a DNA nucleotide is a nitrogenous base. There are four
types of nitrogenous bases found in DNA: adenine (A), thymine (T), cytosine (C), and guanine (G). The
nitrogenous base is a planar, ring-like structure that contains nitrogen atoms.
Deoxyribose Sugar: The second component of a DNA nucleotide is a deoxyribose sugar molecule.
Deoxyribose is a five-carbon sugar that serves as the backbone of the DNA nucleotide. It is a
modified form of ribose sugar with one oxygen atom removed.
Phosphate Group: The third component of a DNA nucleotide is a phosphate group. The phosphate
group consists of a phosphorus atom bound to four oxygen atoms. It provides a negative charge to
the DNA molecule.
These three components (nitrogenous base, deoxyribose sugar, and phosphate group) come
together to form a single DNA nucleotide. The nitrogenous base attaches to the deoxyribose sugar,
forming a nucleoside. The phosphate group then binds to the nucleoside, creating a complete DNA
nucleotide.
In the DNA molecule, DNA nucleotides link together through phosphodiester bonds between the
phosphate group of one nucleotide and the sugar of the next nucleotide. This forms a long chain of
nucleotides that make up the DNA double helix structure.
The Double Helix of DNA.
A DNA molecule is made up of two linked strands that wind around each other to resemble a twisted
ladder in a helix-like shape. Each strand has a backbone made of alternating sugar (deoxyribose) and
phosphate groups. The double helix with the hydrogen bonding between the bases of each strand
allows the DNA to coil to be able to create a compact and longer molecule and store much
information. Hydrogen bonds between complementary bases keeps the two strands of DNA together.
Hydrogen bonds are weak bonds making it easier for the two strands to split from transcription. The
hydrogen bonds are created from the base pairs of with amino acids side chains that are determined
in the genetic code known as “triplet code”.
Proteins are the building blocks of cells and carry out a variety of bodily tasks. DNA acts as the
genetic blueprint for their production.
, Name: Spendilove Agyemang.
ID: 59823.
DNA contains distinct nucleotide sequences called genes that code for different proteins. The
instructions for the arrangement of amino acids that make up a particular protein are encoded in
each gene.
Through the genetic code, the sequence of amino acids in proteins is determined by the nucleotide
bases (adenine, thymine, guanine, and cytosine) in DNA. Codons, for instance, are three-base
sequences that either code for a particular amino acid or signal the beginning or end of protein
synthesis.
Ribonucleic Acid (RNA):
Ribonucleic acid, or RNA, is a molecule that is necessary for many biological functions, mainly the
transfer of genetic information from DNA to proteins. RNA is structurally identical to DNA, but there
are some significant differences. Instead of thymine (T), which is found in DNA, RNA uses the
nucleotide bases adenine (A), cytosine (C), guanine (G), and uracil (U). RNA is usually single-stranded.
There are different types of RNA, but the types I am going to talk about are mRNA, tRNA, rRNA and
SiRNA, and each type of RNA has a specific structure and function.
Genetic Codes:
Codons: Three nucleotide sequences, or triplets, found in messenger RNA (mRNA) that
represent a particular amino acid or signal during protein synthesis are known as codons in
genetics. Every codon function as a start or stop signal for protein translation or codes for a
particular amino acid. For instance, the codon AUG functions as the start codon for protein
production and codes for the amino acid methionine. Transfer RNA (tRNA) molecules contain
sequences of three nucleotides known as anticodons. They function in tandem with mRNA
codons during translation. Through complementary base pairing, anticodons and codons pair
to enable the proper placement of amino acids during protein synthesis.
Degenerate code: Because most amino acids are encoded by numerous codons, the genetic
code is referred to as being degenerate. For instance, six distinct codons (UUA, UUG, CUU,
CUC, CUA, and CUG) encode the amino acid leucine. Given that alterations in the DNA
sequence might not necessarily affect the encoded protein, a certain amount of error
tolerance is provided by this redundancy in the genetic code.
Reading frames: During translation, a sequence of nucleotides can be divided into sets of
three consecutive bases, or codons, in a variety of ways. Nucleotide insertions or deletions
can create a frame shift, which might upset the reading frame and result in a new codon
sequence and possibly the production of an entirely different protein.
Triplet code: Because each codon is made up of three nucleotides, the genetic code is
frequently referred to as a triplet code. During translation, these triplets ascertain the amino
acid sequence of a protein. To put the matching amino acids together into a polypeptide
chain, ribosomes read the codon sequences in mRNA sequentially.
Universal code: The idea that nearly all species share the same codons that code for the
same amino acids is known as the "universal genetic code." The genetic code is shared by the
great majority of living things, including humans and microbes, with very few exceptions.
Because of this universality, genetic information can be shared between other species and
genes and proteins from different creatures can be studied and compared by scientists.
Types, Structures and Functions of RNA.
Messenger RNA (mRNA): mRNA transports genetic data from the DNA in the cell nucleus to the
ribosomes in the cytoplasm. In the process known as protein synthesis or translation, it acts as a
bridge between DNA and proteins.
Structure:
mRNA molecule has only one strand: DNA is usually made up of two strands, but mRNA only
has one. Its single-stranded shape lets it work with other molecules in the cell, like
ribosomes and transfer RNA (tRNA), to make proteins.
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