Foundations of Biology Exam 4: Gene Expression II: Transcription and Translation

many

______ transcripts can be made at the same time

transcriptome

tells you what genes are being expressed

processing in eukaryotes

1. alternative splicing

2. hats (5' caps)

3. shoes (polyA tails)

alternative splicing

introns are removed and exons join together on the mRNA strand

introns

transcribed regions that are removed from pre-mRNA prior to nuclear export

exons

portions of mRNA that join together during alternative splicing and exit the nucleus

protein variation

in eukaryotes, multiple proteins can be made from one gene

snRNP

play a crucial role in the removal of introns (non-coding regions) from primary RNA transcripts; bind to the 5' exon-intron and 3' intron-exon boundaries, and to a branch site within the intron; cuts the intron, which forms a loop (lariat structure) and is then excised

5' MG cap

the 5' end of a pre-mRNA gets a ___ ____ ____ added during processing to help stabilize the mRNA transcript

poly-A tail

the 3' end of a pre-mRNA get a _______ ______ added during processing to help stabilize the mRNA transcript

triplet

a property of genetic code that states all "words" of the genetic language are 3 RNA nucleotides long

non-overlapping

a property of genetic code that states that codons are read once as a group and never read again with any other nucleotides of the sequence

punctuated

a property of genetic code that states that the transcription always start with the start codon AUG and end with one of the 3 stop codons: UAA, UAG, or UGA

redundant

a property of genetic code that states that most amino acids can be coded for by more than one codon; protects from slight mutations

unambiguous

a property of genetic code that states that codons are exclusive and only codes for one specific amino acid

universal

a property of genetic code that states the same codons specify the same amino acids and stop codons in all organisms

3 RNAs that carry out translation

- tRNA

- rRNA

- mRNA

mRNA

the sequence that is made in transcription and the faithfully translated into an amino-acid sequence (=polypeptide or protein) in the cytoplasm or rough ER

tRNA

the ribosome's google translate; links the codon on mRNA with the correct amino acid based of hydrogen bonding of complimentary bases; has a anti-codon that binds to a codon on the mRNA; 'charged' with amino acids

tRNA synthetases

an enzyme that attaches an amino acid to the tRNA with the corresponding anticodon

rRNA (ribosomes)

3D printer of biological life; builds proteins, consists of large and small ribosomal subunits and associated proteins; mediates tRNA binding to mRNA strand and catalyzes the bonds between the amino acids

A site

a tRNA binding site in the large ribosomal subunit; the site where anticodon of charged tRNA bonds with its complimentary codon in mRNA

P site

a tRNA binding site in the large ribosomal subunit; the site where tRNA adds its amino acid to the growing chain

E site

a tRNA binding site in the large ribosomal subunit; the site where tRNA sits before being released from the ribosome

amino (N); carboxyl (C)

proteins are synthesized _______ to _______ ends

prokaryotes

transcription and translation occur together in ___________

does not

processing ________ ____ occur in transcription and translation in prokaryotes