Easy Biochemistry Notes

- It is a  process of protein synthesis -Information carried by m-RNA in the form of genetic code is translated by ribosomes to amino acids and protein is formed. -Occurs in the  cytoplasm -Translation of m-RNA takes place from 5' end to 3' end Requirements for Translation m-RNA t-RNA Ribosomes   Energy in the form of ATP & GTP Specific protein factors initiation factor, elongation factor Steps: Step I. ACTIVATION OF AMINO ACID activation is the process of attachment of amino acid to t-RNA. it takes place in the cytoplasm the CCA 3' end of t-RNA carries a codon that is specific for each of 20 amino acids. the 'D' arm of t-RNA has a site for recognition enzymes as the t-RNA recognizes the amino acid, it gets attached to the amino acid with the help of enzyme aminoacyl t-RNA synthase. in this process, 2 energy bonds are utilized. The activation is a two step process -  1.      formation of AMP amino...

The information present on the template strand of DNA is transcribed for the formation of single-stranded RNA with the help of the enzyme DNA dependent RNA polymerase.

-The property of molecules to exist in more than one form is known as polymorphism , and it is a normal variation and doesn’t have any harmful effect. -The existence of two or more types of restriction fragment patterns is called RFLP. - It is a procedure for the separation and identification of desired fragments of DNA - Restriction endonuclease Enzyme is used for the separation of DNA fragments - Restriction probe s are used for identification of desired fragments -The southern blotting technique is an example of RFLP. Step 1 -Restriction endonuclease enzyme cuts DNA at specific restriction sites into fragments -Different size of fragments are generated along with specific desire fragments Step 2 - Separation of fragments based on length, size, or molecular weight is done by running the pieces on polyacrylamide gel electrophoresis for agarose gel electrophoresis . -Different bands are formed by different size of fragments Step 3 -Denaturation is done by subjecting the g...

DEFINITION: - The combined process of transcription of information present on DNA into m-RNA and then translation of mRNA into a protein is called GENE EXPRESSION. -Regulation of gene expression is essential for metabolic functions, growth & development, and differentiation of tissues. -In prokaryotes, regulation of gene expression occurs at the level of transcription and mRNA synthesis -In eukaryotes, there are two types of regulation : POSITIVE REGULATION : - Because of the presence of a specific regulatory element, if the expression is increased then it is called positive regulation - Any molecule mediating the positive regulation is called as activator or inducer . NEGATIVE REGULATION : -Because of the presence of a specific regulatory element, if the expression is decreased then it is called negative regulation. -Any molecule mediating the negative regulation is called a repressor.

After forming the polypeptide, to become biologically active, it has to undergo a folding process and have to attain its 3d structure. This folding process occurs with the help of a group of specialized proteins called Chaperons .

mRNA formed by the process of transcription is called primary transcript/ heteronuclear RNA/hn RNA It Undergoes extensive modifications to form mature RNA Post-transcriptional processing is not required in prokaryotes. The mRNA is functional immediately after synthesis. In eukaryotes, the process of post-transcriptional modification is much more complicated

PCR invented by Karry Mullis PRINCIPLE It is a technique in which a particular sequence of DNA is amplified and a million copies are produced within few hours REQUIREMENTS : -- Flanking sequence (region adjacent to the gene of interest either upstream to 5' or downstream to 3') should be known --Using the flanking sequence, t wo DNA primer s with 20-30 nucleotides which are complementary to the flanking sequence are synthesized. STEPS OF PCR: 1.Separation/Denaturation -- The strands of target DNA to be amplified are separated by heating at 95 degrees centigrade for 5 seconds for 2 minutes 2.Priming/Annealing: -- The separated strands are cooled at 50degrees centigrade for 30 seconds to 2 minutes. -- The two primers are (one for each strand) are annealed with the complementary single stranded DNA produced in the first step. 3.Polymerization: --to initiate the synthesis of DNA - dNTP's (nucleotide triphosphates) in excess  , DNA polymerase(Taq Polymerase) are added to the mi...

·  Definition: -it is a type of genetic engineering technique in which a gene of one species is transferred to another species by artificial means. Technique of RDNA technology involves: a)SPLICING OF DNA BY RESTRICTION ENDONUCLEASES . -- selection of parent DNA and selectively splitting using restriction endocucleases also called as molecular scissors. -- these restriction endonucleases are isolated from bacteria.e.g - EcoRI from Escherichia coli. -- Function of restriction endonucleases is to identify or recognize specific sequences called as palindrome sequence  (palindromic sequences are inverted repeat sequences i.e the nucleotide sequence is same in both the strands when read in 5' to 3' direction) --  the restriction endonuclease enzymes cut the DNA at the palindromic sequence. --some restriction enzymes cut the DNA fragments in such a manner that there are no unpaired bases on either end  and they are called as blunt ends. --some restriction enzymes cut the D...

 --Change in the base sequence of DNA due to faulty replication or faulty repair of DNA is called as Mutations. --mutations affects somatic cells and so are carried to successive generations. --due to horizontal transmission of mutations ,they  also results in many diseases. --Mutations can be     --Gross that involves large areas of a chromosome (or)     --Subtle that involves only few nucleotides. CAUSES OF MUTATIONS: 1.Errors in DNA repair Mechanisms 2.Spontaneous Change in DNA  3.External/Environmental factors     Physical Agents - Ultraviolet rays/Nuclear rays     Chemical Agents - Deaminating/Alkylating agents --Substance capable of causing mutations are called MUTAGENS. TYPES OF MUTATIONS 1.POINT MUTATIONS/SUBSTITUTION: --Replacement of one base by another base. -- 2 types of point mutations -  a) Transition - replacement of purine by purine and pyrimidine by pyrimidine respectively b)Transversion - Replacement o...

  The Linear arrangements of genes required for metabolism is called as OPERON. The genes involved in making the enzymes necessary for metabolism of lactose is called as LAC OPERON or LACTOSE OPERON. --In 96, Jacob & Monad described the concept of lac operon in E.Coli. STRUCTURE OF LAC OPERON --it is a region of DNA in E.Coli. -- it contains four elements  1.Regulatory Gene(i) - produces repressor protein 2.Promoter site (P) - contains two sites  a) catabolic activator protein binding site(CAP) site b)RNA polymerase entry site to which RNA polymerase gets bound. 3.Operator Site(O) - lac repressor protein produced in the (i) region binds to this site and blocks the transcription initiation 4.Three structural genes (Z,Y,A) coding for  β-galactosidase,galactoside permease & transacetylase respectively required for lactose metabolism REGULATION OF LAC OPERON -E.coli mainly depends on glucose for energy and in the absence of gluco...