Follow genetic information from the chemistry of DNA through gene control, RNA processing, and protein production.
For a protein-coding gene, a cell can copy information from DNA into RNA, process the RNA, and let a ribosome read messenger RNA to assemble a protein. This is a useful model, but many RNAs have jobs of their own and do not become proteins.
Read the supporting reference: Molecular Biology of the Cell · DNA to RNAGenes sit within much longer DNA molecules. Their control regions, transcribed regions, and protein-coding parts have different jobs. These diagrams simplify a complicated system so you can see how the pieces fit.
Each strand has a sugar-phosphate backbone on the outside and bases on the inside. Adenine pairs with thymine; cytosine pairs with guanine. The strands run in opposite chemical directions, called antiparallel.
A flat “ladder” view makes the matching bases and opposite directions easier to see; real DNA twists into a double helix. Nucleotide · Base pair
In this example, transcription moves from left to right. The promoter helps start an RNA copy. The enhancer is drawn upstream just to fit the page; real enhancers can be far away or on either side of a gene. Exons remain in the processed RNA, while an intron is removed. Coding sequence can be split across exons, and untranslated regions stay in the mature RNA without encoding the main protein.
An exon is defined by transcript processing; it may include coding sequence, a UTR, or both. The CDS is the part translated into a protein. An open reading frame is a sequence pattern that may suggest coding potential, but evidence is needed to show that it is translated.
Reference: NHGRI genetics glossary · Molecular Biology of the Cell: DNA structure.
A double-stranded molecule whose sequence stores and passes on hereditary information in most cells.
Explore this idea 02A region of genetic material used to produce a functional RNA; some genes also provide instructions for a protein.
Explore this idea 03A building block of DNA or RNA made of a sugar, a phosphate group, and a nitrogen-containing base.
Explore this idea 04Two complementary DNA bases joined across opposite strands: adenine pairs with thymine, and cytosine with guanine.
Explore this idea 05DNA packaged with proteins and other molecules that organize chromosomes and influence access to genetic information.
Explore this idea 06The regulated use of information in a gene to make functional RNA or, for protein-coding genes, protein.
Explore this idea 07How a cell copies its DNA before division.
Explore this idea 08The process of making an RNA copy from a DNA template.
Explore this idea 09How many eukaryotic RNA transcripts are modified before they are used.
Explore this idea 10RNA molecules that perform functions without serving as templates for protein synthesis.
Explore this idea 11Rules that relate three-base RNA codons to amino acids or translation stop signals.
Explore this idea 12How ribosomes read mRNA and build a protein from amino acids.
Explore this idea 13How cells control when, where, and how strongly genes are used.
Explore this idea 14DNA sequence differences that can have many different effects.
Explore this idea 15Cellular systems that detect and fix many forms of DNA damage.
Explore this idea 16A programmable system adapted from microbial defense to target selected DNA sequences.
Explore this idea 17How a protein chain adopts and maintains a functional structure, with cellular systems handling misfolded products.
Explore this idea 18Biological catalysts that speed reactions; most known enzymes are proteins, while some RNA molecules also catalyze reactions.
Explore this idea 19An RNA molecule that can carry a protein-coding message and can also be regulated by small RNAs or antisense oligonucleotides.
Explore this ideaA regulatory DNA region that can raise transcription by binding regulatory proteins and communicating with a promoter.
Open record Genomic featureA DNA region near a transcription start site where RNA polymerase and associated proteins assemble to begin transcription.
Open record Genomic featureThe DNA position where RNA polymerase begins synthesizing a particular RNA transcript.
Open record Genomic featureA gene segment retained in a mature RNA after processing; an exon may contain coding sequence, untranslated sequence, or both.
Open record Genomic featureA transcribed region removed from many eukaryotic RNA precursors during RNA splicing.
Open record Genomic featureA sequence that can be read in one codon frame without an in-frame stop; a long ORF can suggest protein-coding potential but does not prove expression.
Open record Genomic featureThe part of a transcript annotated as specifying a protein sequence, from its translation start through its termination codon.
Open record Genomic featureThe transcribed portion of an mRNA before its coding sequence; it is present in the mature message but is not part of the main protein-coding region.
Open record Genomic featureThe transcribed portion of an mRNA after its coding sequence that can influence RNA stability, location, and translation.
Open record