Produces a transcript (RNA copy) of a gene. This messenger RNA (mRNA) specifies the amino acid sequence of a polypeptide
Process of synthesizing specific polypeptide on a ribosome using the mRNA template
Eukaryotes also have an intervening step called RNA processing where....
pre-mRNA is processed into active mRNA. Some genes do not encode polypeptides
What are the two types of RNA?
Structural RNAs and Regulatory RNAs
constitute the genetic material. The blueprint for organisms characteristics
These code for Polypeptides
act as a protein to play some role in the cell
One or several polypeptides
determine the structure and function of cells
Activities of proteins
taken together in an organism determines their traits or characteristics
An organized unit of DNA sequences that enables a segment of DNA to be transcribed into RNA and ultimately results in the formation of a functional product
Other genes code for RNA itself as a product
Transfer RNA tRNA and ribosomal rna rRNA
These translates mRNA into amino acids
This rna is part of the ribosomes
Ribosomal RNA rRNA
What are the three stagess of transcription?
Initiation, Elongation and termination
In this step of transcription Recognition step. In bacteria, sigma factor causes RNA polymerase to recognize promoter region. Stage completed when DNA strands separate near promoter to form open complex
RNA polymerase synthesizes RNA. Template or coding strand used for RNA synthesis. Noncoding strand is not used. Synthesized 5 to 3. Uracil substituted for thymine
RNA polymerase reaches termination sequence. Causes both the polymerase and newly-made RNA transcript to dissociate from DNA
What are the three forms of RNA polymerase.
RNA polymerase I, II, and III
This RNA polymerase transcribes for mRNA
RNA polymerase II
This Rna polymerase transcribes nonstructural genes for rRNA and tRNA
RNA Polmerase I and III
Eukaryotic mRNAs are made in a longer pre-mRNA form that requires processing into mature mRNA. What do they contain?
Inrons and exons.
This modification on mRNA is called splicing, what happens?
Introns are removed
This modification on mRNA occurs at the end?
addition of tails and caps
Most structural genes have one or more introns. How are they removed?
What enzyme is used to remove introns?
What are spliceosomes composed of snRNPs
Alternative splicing splicing can occur more than one way to produce different products. rRNA and tRNa are selp splicing, how is this?
They are ribozymes- RNAs that can catalyze reastions.
100-200 adenine nucleotides added to 3 end. Increases stability and lifespan in cytosol. Not encoded in gene sequence
Poly A tail
sequence of bases in an mRNA molecule. Read in groups of three nucleotide bases or codons
Specify a particular amino acid
Codons Also start and stop codons
more than one codon can specify the same amino acid
What is the start codon?
What is the stop codon?
UAA, UAG, or UGA
whats is a codon?
set of three rna nucleotides
3 RNA nucleotide part of tRNA molecule. Allows binding of tRNA to mRNA codon
What are some common feature of tRNA?
Cloverleaf structure, Anticodon, Acceptor stem for amino acid binding
Catalyzes attachment of amino acids to tRNA. one for each of the 20 different amino acids
Overall ribosomes have a shape determined by rRNA. Discrete sites for tRNA binding and polypeptide synthesis.