molecular genetics

Question 1

describe genes, dna, chromosomes

Answer 1

-the genetic material of eukaryotic cells are in the nucleus not only for compartmentalisation, but also as an additional layer of protection for this precious cargo.
-deoxyribonucleic acid (DNA) exists as a double helix and is usually found uncondensed as chromatin threads in the nucleus, and only get packed into x-shaped structures known as chromosomes when preparing for cell division.
-genes are segments of deoxyribonucleic acid with specific sequences of nucleotides that code for the synthesis of specific polypeptides.

Question 2

what is the structure of dna?

Answer 2

dna is a macromolecule comprising of two antiparallel polynucleotide strands. nucleotides are bound within each strand with phosphodiester bonds that make up the sugar-phosphate backbone, and between each strands via hydrogen bonds that form between complementary bases.
all nucleotides comprise of the same three components: a 5-carbon sugar, a phosphate group, and a nitrogenous base

Question 3

what are the 4 nucleotides and their differences?

Answer 3

adenine, cytosine, thymine, guanine
the only difference between the four nucleotides are the different nitrogenous bases that are attached

Question 4

explain complementary base pairing

Answer 4

the different nitrogenous base gives rise to the many different genes that code for so many different polypeptides. this crucial component of dna is arranged such that the bases point into the core of the double helix, protecting them from any potential chemical and physical damage
adenine is complementary to thymine, while guanine is complementary to cytosine. complementary bases will always and only stably form hydrogen bonds with each other, bringing he two antiparallel strands together to form the double helix. the a-t pairing consists of two hydrogen bonds with the c-t pairing is held together by three hydrogen bonds

Question 5

explain dna to protein

Answer 5

the central dogma of molecular biology is a concept that explains the flow of genetic information that begins with dna and end with proteins. two major processes are involved here: transcription of dna to rna(ribonucleic acid), then translation of rna to form polypeptides. the polypeptides then fold into their unique three-dimensional shapes into functional proteins
dna is a stable and permanent molecule that carries the genetic code for all life processes in an organism
rna is a transient molecule that is only made when the relevant gene is transcribed so that a specific polypeptide can be synthesised via translation#
enzymes in the nucleus transcribe dna to rna while ribsomes in the cytoplasm translate rna to synthesise polypeptides.