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Gene to Protein
terms used in describing transcription and translation
Term | Definition |
---|---|
Central Dogma | the flow of genetic information within a cell, starting with DNA (master blueprint) code, to transcribing the code into mRNA that is used in translation to build proteins |
Transcription | Making mRNA by taking DNA nucleic acid language (base pair sequence) and creating a copy in the form of RNA nucleic acid language (base pair sequence) |
RNA | RiboNucleicAcid; single stranded; Contains ribose sugar, uracil replaces Thymine (U instead of T) A-U, C-G base pairing |
Three types of RNA | mRNA, tRNA, rRNA siRNA |
Template strand | the strand of DNA that is used to transcribe mRNA |
Coding strand | The strand of DNA that is not used to create mRNA BUT has the same code as the newly created mRNA |
RNA polymerase 2 | Enzyme required for transcription. RNA polymerase adds nucleotides to the growing mRNA based on the code located on the template strand of DNA |
promoter region | region of the gene that acts as a binding site for RNA polymerase & transcription factors. The promoter region has a base sequence called a TATA box binding site |
Enhancer region | located far upstream of gene that is being expressed. This region turns the transcription rate to HIGH. increasing the speed at which transcription can occur. |
Transcription Factors | A protein complex that binds to the promoter region of a gene in order to turn the gene ON of OFF. To activate the gene expression or inhibit the gene expression |
Exons | the real gene, in other words the parts of the gene sequence that is kept during splicing. The exons have the actual code for the specific protein being made. |
introns | The junk DNA, located inbetween the exons of a gene. These sections are spliced out in order to create a functioning mature strand of mRNA |
mutations | if a single base is added or lost, the reading frame of the mRNA is altered which changes the protein being produces. (insertion, deletion) |
snRNPs | small nuclear RNA proteins that create a spliceosome. The spliceosome cuts out the introns during mRNA processing. |
Alterative splicing | Spliceosomes can cut out different sections of single gene to produce a number of proteins. This increases the complexity of eukaryotic genes as it allows one gene to code for multiple proteins. |
5' cap and poly-A tail | used to protect the mRNA as it leaves the nucleus and enters the cytoplasm. prevents enzymes from breaking down the mRNA |
Translation | converting the RNA nucleic acid language to amino acid language. Translating the code on mRNA to create a protein |
Codon | mRNA has codons that determine the amino acid sequence. Each codon contains a three base sequence. |
AUG | the start codon. EVERY protein starts with methionine, which is the AA that is coded for by the codon AUG |
Anti-codon | the amino acids are carried by tRNA that contains a complimentary base sequence to the codon. Each anti-codon is specific to an amino acid, |
Aminoacyl-tRNA synthetase | the enzyme used to attach the amino acid to the tRNA |
Ribosome | organelle that assists in the production of a protein by holding the mRNA in place while the tRNA's bring in the amino acids. has 1 large subunit and 1 small subunit |
A Site | first binding site on the ribosome, holds the tRNA carrying the next amino acid to be added to the chain |
P site | holds tRNA carrying the growing polypeptide chain (protein) |
E site | exit site, the empty tRNA leaves the ribosome from the exit site |
Building a polypeptide (three phases) | initiation, elongation, termination |
initiation | brings together mRNA, ribosome subunits, and initiator tRNA |
elongation | adding amino acids based on codon sequence |
Termination | end codon, polypeptide is released into the endoplasmic reticulum for processing |
signal recognition peptide | a protein unit that binds to the polypeptide. This signal peptide/recognition protein complex determines how the ER will process the protein. i.e, where is the protein going to be used. |