User:Nurefsanartar/Gene expression

GENE EXPRESSION Gene expression is the process of converting DNA instructions into functional products. protein.


 * The phenomenon in which the information stored in DNA is translated into instructions for making molecules such as proteins is called "gene expression" or "gene expression" for short.


 * Gene expression is a tightly regulated process that enables cells to respond to environmental changes.

It acts as an on-off switch that controls when protein is produced and a volume regulator that increases or decreases the amount of protein produced.


 * There are two critical steps in protein production.

transcriptionItalic text


 * Spelling is the replication of DNA within a gene to produce an RNA transcript called "messenger RNA" or mRNA.
 * This process is carried out by the enzyme "RNA polymerase", which creates mRNA using the bases found in the cell nucleus.

RNA is structurally and characteristically a chemical analogue of DNA. But there is only one basic thread. Also, RNA has uracil bases instead of thymine bases.

TRANSLATIONItalic text


 * Translation takes place after mRNA receives a written message from DNA and carries it to the ribosome, the site of protein production in the cell.


 * The message transmitted by the ribosomal mRNA is read by the "donor RNA" or tRNA.

Reads 3 letters (codons) from mRNA.


 * Each codon denotes a specific amino acid. For example, a "GGU" codon encodes the amino acid glycine. *There are only 20 amino acids, but there are 64 possible codon combinations, so the same amino acid can be encoded by more than one codon. For example, the codons "GGU" and "GGS" both encode for glycine.


 * Each amino acid binds specifically to its own tRNA molecule.


 * When the mRNA sequence is read, each tRNA molecule sends its amino acid to the ribosome, where it temporarily binds to the corresponding codon of the mRNA molecule.


 * When tRNA binds, its amino acids are released and adjacent amino acids are linked together to form long chains called polypeptides. *This process continues until the desired protein is produced.
 * Proteins perform most of the efficient functions of cells.