Nucleic Acids and Transcription and Translation and Mutations: BIO125

what are the bonds between nucleotides called?

phosphodiester bonds

what end are nucleotides always added to?

the 3’ end so energy will be released during reaction

what are the lines that hold two complementary bases together called?

hydrogen bonds

semiconservative replication

the description of DNA having one old and one new strand

transcription

process of DNA to RNA

ribose sugar in RNA

has an OH group

deoxyribose sugar in DNA

has only an H

what does RNA have in place of DNA having T?

U

which RNA often base pairs with itself

tRNA

RNA is single stranded whereas DNA is

double stranded

what is the special cap at the 5’ end of mRNA

special form of G nucleotide, protects end of RNA from degradation and helps bind to ribosome for translation

introns

spliced out of mRNAs, they are meaningless and “in” the way

exons

contain important information for proteins

purpose of long tail of A’s added to 3’ end

helps protect the end helps bind to ribosome for translation

SSBPs

single stranded binding proteins, prevent seperated DNA from reattaching

topoisomerase

relieves tension from twisting in the DNA being replicated

DNA ligase

seals nicks in newly created DNA strands

DNA polymerase

adds new nucleotides to the growing strand

leading strand

strand that is replicated continuously

lagging strand

strand that is replicated in Okazaki fragments, about 200 bp at a time

sliding clamp

helps hold DNA polymerase onto the DNA strand

primase

enzyme that adds RNA primers single stranded DNA to give starting point for DNA polymerase

helicase

unwinds the DNA double helix

RNA primer

short sequence of RNA nucleotides base paired to the DNA to give a starting point for DNA polymerase

what do tRNAs contain

an anticodon and amino acid

what are ribosome small and large subunits made of

many rRNAs and proteins

3 tRNA sites on a ribosome

A site (amino acyl site), P site (peptidyl site), and E site (exit site)

A site

tRNA anticodon h bonds to mRNA codon

do eukaryotes perform transcription and translation simultaneously?

no, they are seperate processes

how many amino acids are in the genetic code

20

how many codons are in the genetic code

64

mutations

any change to DNA sequence

substitution

swapping of an nucleotide

deletion

removal of a nucleotide

insertion

adding a nucleotide that wasn’t previously in the DNA

inversion

swapping adjacent nucleotides

silent protein mutation

nucleotide change but no amino acid change

nonsense protein mutation

premature stop

missense protein mutation

amino acids is swapped for another

conservative missense mutation

swapped for a similar amino acid

non conservative missense mutation

swapped for a structurally different amino acid

which mutations almost always cause issues to proteins

insertion and deletion, mess with the the multiples of 3