DNA Flashcards
simple flow of DNA (central dogma)
- DNA replication -> DNA
-transcription-> RNA -translation-> Protein
purposes of DNA
CODE FOR:
- regulate exchange of DNA
-energy transfer
- protein synthesis
- pass traits to next generation
Label DNA
- phosphate group
- Phosphodiester bond
- ribose sugar
- nitrogenous base
- hydrogen bond
differences between RNA and DNA
DNA:
- deoxyribose sugar
- A, T, C and G
- double stranded
- more stable
RNA:
- ribose sugar
- A, U, C, G
- single stranded
- less stable
What are purines
- A and G (pure as gold)
- two rings of nitrogen
what are pyramidines
- C and T (CH3 at 5-carbon), and Uracil (H atom at 5-carbon position)
- One ringed
How is DNA named
- sugar
- base
- number of phosphates (always 1)
e.g. deoxyadenosinemonophosphate
how is RNA named
- base
- number of phosphate groups (always 1)
e.g. adenosinemonophosphate
how many bonds between A and T vs C and G
2 for AT
3 for CG
why is DNA changed to RNA for protein synthesis?
- so it is small enough to fit through nuclear pores and only contains useful coding info (exons)
what is transcription
- process by which RNA is transcribed from DNA
what is:
tRNA
rRNA
mRNA
t = transfer RNA (pol 3)
m = messenger (pol II)
r = ribosomal (pol 1)
where does transcription occur
nucleus or nucleoid
Explain process of transcription
- RNA polymerase binding - binds to promotor region in non-coding area
- Initiation - RNA polymerase unwinds DNA and moves in 3’ to 5’ direction. Adds complimentary nucleoside trophosphates (e.g. GTP) onto template strand (synthesising RNA in 5’ to 3’ direction), forms phosphodiester bonds between them
- Elongation - continuation
- Termination - at end of gene, stop sequence read, termination signal received by polymerase. hairpin structure forms
- RNA pol detaches
template vs coding strand
BOTH are genes (sections of DNA), not the whole DNA strand itself
template - complimentary to code wanted
coding - contains actual code we want in mRNA