intro to DNA Flashcards
what is the central dogma
DNA >(transcription)>RNA >(translation)> Protein
what is structure RNA
ribose, oxygen on C2
what is structure of DNA
deoxyribose, no oxygen on C2
structure of DNA/RNA : nucleoside
base and 5 carbon sugars
structure of DNA/RNA: nucleotide
nucleoside and phosphate group
which bases are purines
adenine and guanine
which bases are pyrimidines
cytosine, thymine and uracil
how to phosphodiester bonds form
form between 3’ OH group and 5’ triphosphate, link nucleotides. New nucleotides only added to a free 3’ end. Can only go in 1 direction
what does DNA look like
- Anti-parallel double helix. One strand 5’ to 3’, other strand 3’ to 5’
- Sugar-phosphate backbone
- Base pairs in the inside, held together with H bonds
DNA replication leading strand
Leading synthesized in 5’→ 3’ direction - catalyzed by DNA polymerase
DNA lagging strand replication
Lagging is synthesized in Okazaki fragments which are then joined by DNA ligase
Primase starts replication and starts RNA sequence at start of new strand
what can happen if the wrong nucleotides are added during replication of DNA
Wrong nucleotide can result on mutations
how does the body avoid mutations during replication of DNA
DNA polymerase has exonuclease activity that goes along and ‘proofreads’ the sequence changing any errors
where does replication start in the genome
- In eukaryotes, replication starts simultaneously at several points in the genome. this helps speed up the process
what does tRNA do
carries amino acids to be incorporated into proteins
