Transcription (biology)Transcription is the process of duplicating a segment of DNA into RNA for the purpose of gene expression. Some segments of DNA are transcribed into RNA molecules that can encode proteins, called messenger RNA (mRNA). Other segments of DNA are transcribed into RNA molecules called non-coding RNAs (ncRNAs). Both DNA and RNA are nucleic acids, composed of nucleotide sequences.
CistronA cistron is a region of DNA that is quite similar to a gene, so much so that the terms are considered synonymous by some, especially with regard to the molecular gene as contrasted with the Mendelian gene. The debate whether or not a cistron is the same thing as a gene, revolves around what size a segment of DNA constitutes as a unit of selection.
Gene expressionConversion of a gene's sequence into a mature gene product or productsFlowchart of gene expression.Gene expression is the process by which the information contained within a gene is used to produce a functional gene product, such as a protein or a functional RNA molecule. This process involves multiple steps, including the transcription of the gene's sequence into RNA.
ProkaryoteA prokaryote (; from Ancient Greekpró, meaning 'before'; and káruon, meaning 'nut' or 'kernel'), less commonly spelled procaryote, is a cellularorganism that lacks a distinct cell nucleus or other membrane-bound organelles. In the earlier two-empire system, prokaryotes formed the empireProkaryota; in the current three-domain system, based upon molecular phylogenetics, prokaryotes are divided into two domainsBacteria and Archaea.
GeneIn biology, the word gene has two meanings. The Mendelian gene is a basic unit of . The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce RNA. There are two types of molecular genes: protein-coding genes and non-coding genes. During gene expression (the synthesis of RNA or protein from a gene), DNA is first copied into RNA. RNA can be directly functional or be the intermediate template for the synthesis of a protein.
Promoter (genetics)1: RNA Polymerase 2: Repressor 3: Promoter 4: Operator 5: Lactose 6: lacZ, 7: lacY, 8: lacA.Top: The transcription of the gene is turned off. There is no lactose to inhibit the repressor, so the repressor binds to the operator, which obstructs the RNA polymerase from binding to the promoter and making the mRNA encoding the lactase gene. Bottom: The gene is turned on.
DNADeoxyribonucleic acid (pronunciation; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of all known organisms and many viruses. DNA and ribonucleic acid (RNA) are nucleic acids.
Messenger RNAMessenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of synthesizing a protein. mRNA is created during the process of transcription, where an enzyme (RNA polymerase) converts the gene into primary transcript mRNA (also known as pre-mRNA). This pre-mRNA usually still contains introns, regions that will not go on to code for the final amino acid sequence.
RNA splicingRNA splicing is a process in molecular biology where a newly-made precursor messenger RNA (pre-mRNA) transcript is transformed into a mature messenger RNA (mRNA). It works by removing all the introns (non-coding regions of RNA) and splicing back together exons (coding regions). For nuclear-encoded genes, splicing occurs in the nucleus either during or immediately after transcription.
OrganelleAn organelle is a specialized subunit, within a biological cell, that has a specific function. The name organelle comes from the idea that these structures are parts of cells, as organs are to the body, hence organelle, the suffix -elle being a diminutive.
Translation (biology)Translation is the process in biological cells in which proteins are produced using RNA molecules as templates. The generated protein is a sequence of amino acids determined by the sequence of nucleotides in the RNA. The nucleotides are considered three at a time. Each such triple results in the addition of one specific amino acid to the protein being generated. The matching from nucleotide triple to amino acid is called the genetic code.GeneticsScience of genes, heredity and variationGenetics is the study of genes, genetic variation, and in organisms. It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a MoravianAugustinian friar working in the 19th century in Brno, was the first to study genetics scientifically. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring over time.*As an Amazon Associate I earn from qualifying purchases.