Unit 11
Assignment A - Cell division
Scenario:
I have applied 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.
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, Structure of nucleotides
A nucleotide could be defined to be the basic building
block of nucleic acids which are RNA and DNA.
Nucleotides consist of one singular sugar molecule; the
type of sugar molecule differs in RNA and DNA. In RNA
the singular sugar molecule is ribose and in DNA the
singular sugar molecule is deoxyribose. Nucleotides
are attached to a nitrogen containing base and a
phosphate group, they are also essential for executing
metabolic and physiological activities.
DNA (Deoxyribonucleic acid)
DNA is a double stranded molecule (helix), where each strand consists of a polymer of nucleotides
that are joined by a sugar-phosphate backbone. The two strands are held
together by hydrogen bonds which act between the bases of each of the
strands. The two polynucleotide units that make up the double helix are
joined by hydrogen bonds. The complementary base pairs are connected
by these hydrogen bonds. Long sequences of the bases, which are
represented by the letters A, C, G, and T, make up each strand of DNA.
One strand of DNA's bases aligns with "complimentary" bases on the
other strand. Unique nucleotides are required to produce complementary
base pairs with DNA bases. These are guanine with cytosine and adenine
with thymine. Our genome receives instructions from the sequence of
these nucleotides, which produces our individual code.
Deoxyribonucleic acid stores information which are used to produce
other larger molecules, these larger molecules are called proteins. The instructions of what protein is
meant to do is stored inside of cells, they are distributed amongst 46 long structures that are called
chromosomes. Chromosomes are composed of thousands of shorter parts of DNA, which are called
genes.
DNA does command/direct instructions that would be needed for a living organism to survive,
reproduce, and further develop. DNA sequences are converted into messages that are used produce
proteins (as mentioned above). Proteins are the compounds that are used to do most of the work in
living organisms.
Transcription and translation of DNA (deoxyribonucleic acid) occur during the production of all
proteins in the body. Transcribing DNA into RNA is known as DNA transcription. The transcribed RNA
is employed as a genetic blueprint during translation to turn the information into proteins, which are
essential for all the body's cells to operate.
There are three distinct RNAs that are important to the process of protein synthesis when DNA is
transformed into RNA during this process of DNA transcription and translation. The messenger RNA
(mRNA), transfer RNA (tRNA), and ribosomal RNA are the three different forms of RNA (rRNA).
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