Unit 6 - DNA + RNA Flashcards
protein synthesis
process of building proteins by using the code in DNA
what is the central dogma of biology?
protein synthesis, DNA leading to proteins being made
differences between DNA and RNA
DNA - deoxyribose, double stranded, thymine, C=G, A=T
RNA - ribose, single stranded, uracil, C=G, A=U
messenger RNA
mRNA, carries coded message to cytoplasm from nucleus
ribosomal RNA
rRNA, found in ribosomes
transfer RNA
tRNA, carries amino acids to ribosomes and matches them to mRNA strand
transcription
DNA - RNA, forms mRNA, mRNA carries message to make proteins
steps of transcription
1) DNA unzips
2) enzyme RNA polymerase uses one DNA strand as a template to assemble nucleotides into RNA
how does RNA polymerase know where to start making RNA and where does it start
starts at promoter regions, area on DNA strand that signals RNA polymerase to start making RNA
introns
segments removed from RNA, cut out and discarded, “in the way”
exons
remaining pieces of mRNA that will be used to make a protein, “expressed”
where does transcription take place
nucleus
translation
process of changing the info carried by the mRNA molecule into a sequence of amino acids that make up a protein
how many amino acids are there
20
codon
three nitrogenous bases on mRNA strand, each represents an amino acid
how many different codons are there
64
what does tRNA do
each one brings an amino acid to the mRNA, tRNA has anticodon that bonds to codon on the mRNA strand
what is the start codon
AUG
what are the stop codons
UAA, UAG, UGA
____ is a chain of amino acids and once it’s folded it becomes a _____
polypeptide, protein
primary stage of protein
chain of amino acids (polypeptide)
secondary stage of protein
amino acids hydrogen bond to form helices and sheets
tertiary stage of protein
3d structure of a protein, attractions form between helices and sheets
quaternary stage of protein
protein insisting of more than one amino acid chain (polypeptide)
what are the monomers of DNA
nucleotides
what are the three parts of nucleotides
simple sugar (deoxyribose), phosphate group, nitrogenous base (carbon ring structure)
nitrogenous bases
carbon rings that have nitrogen
what are the four nitrogenous bases
adenine, guanine, cytosine, thymine
purines
2 rings, adenine and guanine, “AG is 2 pur”
pyrimidines
1 ring, thymine and cytosine
what are the sides or “backbones” of DNA made out of
phosphate and sugar
what are the “steps” of DNA made of
nitrogenous bases
how many hydrogen bonds are there between A and T
2
how many hydrogen bonds are there between C and G
3
which way is DNA twisted
clockwise
what are the sides of DNA
anti-parallel
what are the parts of chargaff’s rule
- in DNA, the amount of A=T and the amount of C=G
- amount of (A=T)=(C=G)
- DNA varies between species based on amounts of A, C, T, G
who “discovered” the shape of DNA
Watson and crick
who used x-ray diffraction to take a picture of DNA
Rosalind Franklin
when did Watson and crick discover the shape of DNA
1953
when did Rosalind Franklin take a picture of DNA
1951
dna replication
used during cell division and mitosis when each cell needs the correct amount of DNA
where does DNA replication take place
nucleus
what happens during DNA replication
DNA splits apart and two new identical strands are made
what are the steps of DNA replication
1) DNA molecule unzips and each strand acts as a template, enzyme breaks breaks hydrogen bonds between hydrogen bases
2) nucleotides floating near strand begin to bind to the new strand
3) 2 new DNA strands are formed
semi conservative replication
each new DNA strand has one half of the original DNA strand
when does DNA replication happen
before mitosis in the s phase of interphase
DNA polymerase
enzyme that joins individual nucleotides to produce a new strand or DNA
helicase
splits or unzips dna
primase
builds the primer
ligase
connects or glues DNA DNA fragments, “lig” = connect
which direction does DNA polymerase build
5’ - 3’
which direction does DNA polymerase read
3’ - 5’
what is the name of the strand of DNA that the DNA polymerase builds continually on as it unzips toward the replication fork
leading strand
what is the name of the strand of DNA that the DNA polymerase builds in fragments away from the replication fork
lagging strand
what are the sections of DNA built in fragments on the lagging strand called
okazaki fragments
replication fork
active area where DNA replication takes place
change in the DNA sequence
mutation
anything that causes a mutation
mutagen
radiation, carcinogens, mistake in DNA replication, are all examples of
mutagens
what are the two categories of DNA - level mutations
point and frameshift
change in a single base pair in DNA
point mutation
what is point mutation also called
substitution
what are the types of point mutations
silent, missense, nonsense
silent point mutation
codon changes but resulting amino acid is the same
missense point mutation
changes one amino acid
nonsense point mutation
results in an early stop codon
insert or delete base pair
frameshift mutation
sickle cell is an example of which type of mutation
point mutation
huntington’s disease and muscular dystrophy are examples of which type of mutation
frameshift
section of DNA that codes for a specific protein
gene
cutting DNA strand into small fragments and inserting them into another organism’s DNA of the same or different species is called:
genetic engineering
strand of DNA created by combining pieces/fragments of DNA from different organisms
recombinant dna
organisms that contain recombinant dna
transgenic/host organism
how to scientists cut DNA to make recombinant dna
using enzymes
how is genetic engineering used
industry, medicine, ag, basic research
all genes of an organism
genome
what was the human genome project and what was the goal
thirteen year international project, goal was to map all the genes of a human
eugenics movement and it’s goal
movement beginning in 1800’s, goal was to improve genetic quality of the human population, tried to increase reproduction of humans with higher traits and decrease reproduction of people with lower traits
