chapter 9 Flashcards
Rosalind Franklin founded
x ray diffraction pattern of dna; this helped find the double helix structure
what three things are each nucleotide made of?
phosphate, sugar and a base
what kind of nucleotides are DNA and RNA
polynucleotides
difference between ribose and deoxyribose
different element at 2’, H in deoxyribose and OH at ribose
what is dna made of
two polynucleotide joined together by two hydrogen bases, twisted into helical shape
where is the sugar phosphate bone
on the outside
where are the nitrogenous bases (pair)
they are perpendicular to each other in the interior
what forms when A pairs with T
two hydrogen bonds
what forms when G pairs with C
three hydrogen bond
where is DNA found in
Eukaryotes:
Prokaryotes:
Eukaryotes: Nucleus
Prokaryotes: Nucleoid (cytoplasm)
What happens in cell replication? (how does it work)
DNA is broken into two, forms / pairs with a new strand
What direction does DNA replication happen in?
5’->3’
replication is continuous on
3’->5’
replication is discontinuous (forms short segments) on
5’->3’
dna replication begins at _____ and ____ to produce a bubble
the origin; unwinds
helicase ___ the helix
unwinds
where is the nucleotides add to the growing chain? (dna polymerase)
end of 3’; can only be added where there is an OH
backbone is sealed by
DNA Ligase
DNA is transcribed to
RNA
RNA is transcribed to
Protein
how is the phenotype determined
presences and action of protein
sequence of dna provides
code for constructing protein
Transcription means
to rewrite the DNA code to RNA using its “language”
words in the translation are called
codon
RNA to protein “language” is
Nucleotide “language” to amino acid “language”
codon
three nucleotides specify one amino acid
redundant
more than one codon can make this amino acid
ambiguous
codon made for one amino acid that does not code with others
Stages of transcription:
Initiation-
Elongation-
Termination-
Initiation- RNA polymerase binds to a promoter while helix unfolds
Elongation- RNA added to the chain (tracks DNA template in 5’->3’ ; unwinds and rewinds DNA as it is read)
Termination-RNA polymerase reaches a terminator sequences and detaches from template
introns
eukaryotic mRNA
exons
separates coding regions
mutation
change in nucleotide sequence
spontaneous mutation
happens because on an error in dna replication of recombination
RNA splicing
removing of introns to join exons together producing continuous coding sequences
rRNA
ribose RNA
mRNA
messenger RNA
tRNA
transport RNA
