DNA
MOLECULE – SCI & TECH
News:
A genetic circuit on a
single DNA molecule as an autonomous dissipative nanodevice
What's
in the news?
●
Realizing genetic circuits on single DNA
molecules as self-encoded dissipative nanodevices is a major step toward
miniaturization of autonomous biological systems.
Key
takeaways:
●
A circuit operating on a single DNA
implies that genetically encoded proteins localize during coupled
transcription-translation to DNA, but a single-molecule measurement
demonstrating this has remained a challenge.
DNA:
●
Genetic
carrier - Deoxyribonucleic acid (DNA) is the molecule that
carries genetic information for the development and functioning of an organism.
●
Two
strands - DNA is made of two linked strands that wind around
each other to resemble a twisted ladder, a shape known as a double helix.
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Each strand has a backbone made of
alternating sugar (deoxyribose) and phosphate groups
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The two strands are connected by chemical
bonds called bases.
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Four
bases - Adenine (A), Cytosine (C), Guanine (G) and Thymine
(T).
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Proofreading
- The enzymes responsible for copying DNA, collectively known as DNA
polymerases, possess error-correction
property, known as ‘proofreading’.
RNA:
●
Ribonucleic acid (RNA) is a nucleic acid
present in all living cells that has structural similarities to DNA.
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RNA is most often single-stranded.
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An RNA molecule has a backbone made of
alternating phosphate groups and the sugar ribose.
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Attached to each sugar is one of four bases: Adenine (A), Uracil (U),
Cytosine (C) and Guanine (G).
Types
of RNA:
●
Different types of RNA in cells are
messenger RNA (mRNA), ribosomal RNA (rRNA) and transfer RNA (tRNA).
Other
Key takeaways of RNA:
●
Some RNAs are involved in regulating gene
expression.
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RNA polymerases do not possess the ability to proofread.