Lecture 8 Flashcards
Transcription & Gene Expression
What is the central dogma of biology?
DNA is transcribed into RNA which is translated into Protein
What is RNA (ribonucleic acid)?
A polymer of ribonucleotides linked together by 3’-5’ phosphodiester linkage
What type of sugar does DNA have ?
Deoxyribose
What type of sugar does RNA have?
Ribose
Does DNA have a hydroxyl group in the second carbon ?
No
Does RNA Have a hydroxyl group in the second carbon?
Yes
Where is DNA located?
Nucleus
Where is RNA located ?
Nucleus and cytoplasm
___ is less stable, therefore more reactive
RNA
___ is more stable, therefore less reactive
DNA
What are the different types of RNA and what are their functions?
messenger RNA (mRNA) - carries information from DNA to ribosomes in the cell. determines the amino acid sequence in the protein produced
ribosomal RNA (rRNA) - incorporates into the ribosomes
transfer RNA (tRNA) - used to transfer specific amino acids to polypeptide chains in ribosomes ( this occurs during translation)
What are the types of sizes of RNA ? (something like that)
-small nuclear RNA (snRNA)
-microRNA(miRNA) - used to regulate gene activity (size ~21-22 nucleotides)
-small nucleolar RNA (snoRNA)
-long non-coding RNA (IncRNA)
What is an exon?
Coding region
What is an intron?
Noncoding region
Who was awarded the Nobel Prize (2006) for molecular basis of eukaryotic transcription?
Roger D. Kornberg
Who was awarded the Nobel Prize (1993) for discover of introns and gene splicing ?
Phillip Sharp and Richard Roberts
Who was awarded the Nobel prize (1968) for their interpretation of the genetic code and its function in protein synthesis?
Marshall W. Nirenberg, Har Gobind Khorana, and Robert W. Holley
DNA is transcribed into RNA by what?
RNA polymerase
How does the process of transcription begin?
RNA polymerase attaches to the template DNA promoter and begins to catalyze production of complementary RNA
What kind of bonds join the two strands of DNA?
Hydrogen bonds
What are the different functions in RNA polymerase II
mRNA - encodes protein
snRNA - RNA splicing
siRNA - Chromatin-mediated repression, translation control
miRNA - translation control
What are the three steps of gene transcription?
1) Initiation
2) Elongation
3) Termination
