Genes(DNA, RNA)

 Lecture 2 Genes(DNA, RNA) 

DNA/RNA 

Nucleic Acid- Nucleic acid carry information in cells and make up genetic material. Nucleotide is the basic building block of Nucleic acid. 

Nucleotide = Nitrogenous Base + Sugar + Phasphoric Acid 

If present sugar is

Deoxyribose Sugar, then it will be DNA

Ribose Sugar, then it will be RNA

Extracellular DNA(eDNA)- also known as cell free DNA has major application in the field of healthcare. 

Recombinant DNA(rDNA)- created by combining two or more DNA fragments from different sources. Sometimes also called chimeric DNA. American Biochemist, Paul Berg created first recombinant DNA that led to the evolution of genetic engineering. 

Gene- A short stretch of DNA with specific code

Father of Genetics- Gregor Mendel(Pea experiment) 

Genome- All the genetic information of an organism. 

Nuclear genome + Mitochondrial genome + Chloroplast genome

Human genome project(HGP)- An international scientific research project successfully completed in the year 2003 by sequencing the entire human genome of 3.3 billion base pairs.

Genome India Project(GIP)- Project by Department of Biotechnology(DBT) + IISc, Bangaluru to map genome of 10000 Indians.

IndiGen Genome Project- An initiative of the Council of Scientific and Industrial Research(CSIR) to collect and sequence the genomes of the ethnic Indian population(1008) 

DNA barcoding- DNA analysis to identify a species. 

DNA profiling(DNA fingerprinting)- (Developed by Alec Jeffrey)DNA analysis to identify an individual by matching the extracted DNA base pairs with existing ones. 

Father of Indian DNA fingerprinting- Prof Lalji Singh

Blotting Techniques- Process of transferring macromolecules(Proteins, Nucleic acids, etc.) from a gel to the solid surface of membrane to detect the molecules. 

           Southern Blot → DNA detection

           Northern Blot → RNA detection

           Western Blot → Protein detection

Chromosome

Human cells have 23 pairs of chromosomes (22 pairs of autosomes and one pair of sex chromosomes)

Sex Chromosome- Male(XY), Female(XX)

1 Chromosome = 1 DNA coated with Proteins

DNA(coated with histone protein) → Chromatin(further coated with protein) → Chromosome

Chromatin allow DNA replication but Chromosome doesn't. 

Chromatid- identical half of double stranded DN

Epigenetics- Change in Chromosome without any change in DNA(genes). 

Gene editing- Genetic material to be added, removed, or altered without addition of foreign gene

Genetic engineering(Genetic Modification/GM)- Use of technology to modify and manipulate an organism's genes. This can be done with or without adding the foreign genes. 

Gene editing is a subtype of Genetic engineering. 

Restriction Enzymes(Restriction Endonucleases)- Naturally occurring enzymes that cut the DNA and molecules into smaller substances. They are present in prokaryotic organisms.

CRISPR/Cas9 technology- Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) is a gene editing technology using a special protein called Cas9. The Cas9 protein acts like a pair of scissors to cut the designated location of DNA. 

CRISPR technology is more accurate and easy to use than the use of restrictions enzyme. 

Gene Knockout- Deactivation or deletion of specific genes by cutting DNA at targeted region

Gene Silencing/Gene Knockdown- This method involves turning off specific genes using RNA interference

Terminator Technology/Suicide Seeds- GM traits will work in first generation seeds only. 2nd generation seeds will not have desired traits. 

Genetic Engineering Appraisal Committee(GEAC)- statutory body under Ministry of Environment, Forest and Climate change established under Environment protection Act 1986 to approve the research, laboratory testing, import-export and commercial cultivation of GM crops. 

Flavr Savr tomato- first commercialized GM crop. 

Bt cotton is only GMO crop with commercial production in India

Dhara Mustard Hybrid-11(DMH-11) got environment release approval from Genetic Engineering Appraisal Committee(GEAC)

Protein Synthesis-

DNA replication- Process of producing two identical replicas of DNA from one original DNA molecule during cell division, growth and repair of tissue. 

Transcription- Segments of DNA transcribed into RNA molecules to encode Protein. 

Reverse Transcription- Synthesis of DNA from an RNA template. 

Translation- Protein making process using the genetic information carried in messenger RNA (mRNA). 

Coding RNA- messenger RNA(mRNA) that encodes protein. 

Non-coding RNA- Cellular regulators that do not encodes protein. 

Protein Synthesis process-

Replication → Transcription → Translation

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