BIOL 224 - Chapter 12 - Gene Expression at the Molecular Level
Terms in this set (53)
Father of genetics
a British Physician who was studying the inheritance of the disease Alkaptonuria, proposed a link between genes and the production of enzymes.
Inborn Errors of Metabolism (IEM)
A group of congenital conditions that cause either accumulation of toxins or disorders of energy metabolism in the neonate. These conditions are characterized by an infant's failure to thrive and by vague signs such as poor feeding.
Beadle and Tatum
Showed that genes code for enzymes
One Gene One Enzyme
1. Genes do control the production of enzymes, but not all genes encode enzymes
2. Not all enzymes consist of a single polypeptide. Some multimeric proteins are formed by the product of multiple genes, each producing a separate polypeptide which combine to form the enzyme.
3. Some genes are alternatively spliced to produce multiple proteins, or versions of a protein. So some genes produce multiple proteins.
"Central Dogma" of Biology
traces the path of information flow within cells, DNA -> Transcription -> mRNA -> Translation -> Polypeptide
DNA directed RNA synthesis
one molecule concerned with Transcription, attaches to DNA and denatures DNA.
region of gene where RNA Polymerase attaches to Transcribe gene
carries information from DNA to the ribosome
type of RNA that combines with proteins to form ribosomes
escorts amino acids to the ribosome
precursors for transcription, line up opposite DNA Template strand and RNA Polymerase connects them together in the 5'→3' direction.
RTM (Ribonucleoside Triphosphates Mechanism)
removal of pyrophosphate and polymerization of Nucleotide to 3' end of growing RNA chain
The enzymatic processing of the eukaryotic primary RNA transcript to produce a mature transcript; production of a mature mRNA requires capping, polyadenylation and intron splicing.
the removal of introns can occur a=to any type of RNA, from the action of spliceosomes
Special molecules that assist in the editing of mRNA during RNA processing, a complex of RNA and proteins
process by which one or more nucleotides in an RNA can be changed, added, or removed
one nucleotide is substituted for another
nucleotides are added/deleted from the total number of bases
converts cytosine to uracil
converts an A to inosine (I), which the ribosome Translates as a G.
RNAs that guide the insertion or deletion of uridine residues into mitochondrial mRNAs
3 bases make up a Codon
a sequence of 3 bases in mRNA which code for an Amino Acid
stop translation rather than insert and amino acid
2D shape - 3 leaf clover
the 3' end of a tRNA molecule; the portion that amino acids become attached to during the tRNA charging reaction
Load proper Amino Acid onto tRNA using energy from ATP, attach the correct amino acid to tRNAs
large and small subunits each constructed of one or more rRNA and 20-30 proteins
the parts automatically come together to form Ribosomes
Ribosomes (3 positions to hold tRNA)
1. A site - holds new tRNA
2. P site - holds tRNA with polypeptide chain
3. E Site - holds empty tRNA to exit the ribosome
holds new tRNA
holds the tRNA carrying the growing polypeptide chain
the exit site, where discharged tRNAs leave the ribosome
1st Step of Translation
small ribosomal subunit attaches to 5' end of mRNA
2nd Step of Translation
first tRNA attaches to small subunit P site
3rd Step of Translation
Large ribosomal subunit attaches to form complete ribosome
4th Step of Translation
First Aminoacyl-tRNA has attached at P-site, 2nd Aminoacyl attatches at a-site of ribosome, matching 2nd codon
5th Step of Translation
Peptidyl transferase catalyzes a peptide bond between the first 2 AAs by transferring the first AA from the first tRNA to the 2nd AA
6th Step of Translation
Translocation moves ribosome to next codon, using GTP as an energy source, with release of first tRNA from the exit (e) site. 1st AA attached to 2nd, which is attached to 2nd tRNA
7th step of translation
3rd Aminoacyl-tRNA anticodon attaches to the A-site of the ribosome according to the 3rd mRNA codon
8th Step of Translation
Peptidyl transferase catalyzes next peptide bond, ribosome translocates in the 3' direction once more
10th Step of Translation
upon reaching Termination (stop) codon, a releasing protein attaches instead of an aminoacyl tRNA
one mRNA and all the multiple ribosomes translating it at the same time
proteolysis, glycosylation, phosphorylation
the breakdown of proteins or peptides into amino acids by the action of enzymes
The process of adding a carbohydrate to a protein
The metabolic process of introducing a phosphate group into an organic molecule.
(Ways in which mRNA can be) post-transcriptionally modified
addition of a 5' 7-methyl Guanosine "Cap," and the Addition of a Poly-A "Tail"
three step mechanism used to load the appropriate amino acid onto each tRNA
1. the Aminoacyl tRNA Synthetase binds ATP and the specific Amino Acid recognized by that Activating Enzyme. The energy from ATP is transferred to the Amino Acid as AMP.
2. Synthetase binds one of the group of tRNAs recognizing that amino acid, and the Amino Acid is transferred from the AMP to the tRNA.
3. tRNA, charged with the appropriate Amino Acid is released, as is the Enzyme (in an unaltered state).
internal RNA template
what telomerase uses to add new nucleotides to the new telomeres chromosomes
Post-Transcriptional Modification of rRNA
Removal of Introns