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62 terms

Biology Exam 5

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Describe DNA structure
A double stranded, helical molecule. Components of DNA are: 1) Deoxyribase(5)
2) Phosphate
3) Bases (A,T,C,G)
Describe DNA replication
the 2 strands unwind and create an "initiation site" which more DNA is created.
Describe replication forks
Site where helix is growing and unzipped.
Describe the direction of elongation
Leading: Continuous strand (towards)
Lagging: Discontinuous strands (away)
continuous DNA assembly
the original 5' to 3' ("leading strand") strand is released from its 3' end so the complement is generated in its 5' to 3' direction, continuously. There is no need to pause.
DNA polymerase vs. ligase
Polymerase binding ; Ligase lagging only
define template
DNA which is copied
define triplet
every 3 bases (start AUG)
define genetic code
basic language 22AA and 64 codons
define mutation
a change in your DNA
DNA vs. RNA
DNA has deoxyribose and A, T, C, G. RNA has ribose sugar and A, U, C, G.
Define transcription
DNA sequence is copied (or transcribed) into an mRNA.
Define translation
Where the genetic code carried by mRNA is decoded to produce the specific sequence of amino acids in a polypeptide chain.
Define replication
The process of duplicating or producing an exact copy of a polynucleotide strand such as DNA.
rRNA function and location
A nucleic acid found in all living cells. Plays a role in transferring information from dNA to the protein-forming system of the cell. More specifically, rRNA sits in the Ribosome, decoding the mRNA into various amino acids and assisting in translation.
mRNA function and location
produced and processed in the Nucleus they are transported to the cytoplasmic ribosomes, and is the instructions for the creation of a protein.
tRNA function and location
to transfer specific amino acids to growing polypeptide chain during the ribosomal site of protein synthesis during what you call translation. location is outside the nucleus and associated with the ribosome.
define promoter region
dNA sequences which are recognized (directly or indirectly) and bound by a dNA-dependent rNA polymerase during the initiation of transcription
define RNA polymerase
an enzyme that is responsible for making rna from a dna template. In all cells RNAP is needed for constructing rna chains from a dna template, a process termed transcription.
start codon
The codon 5' AUG in mRNA, at which polypeptide synthesis is started.
stop codon
The three codons, UAA known as ochre, UAG as amber and UGA as opal, that do not code for an amino acid but act as signals for the termination of protein synthesis.
P vs. A binding sites on ribosome
P & A are a region of a messenger RNA molecule that binds the ribosome to initiate translation. A is first and makes sure the part fits and P is the second and it makes the chain
exons
The protein-coding region in the DNA. The nucleic acid sequence in the DNA, or RNA transcript following genetic splicing.
introns
Non-coding, intervening sequences of dna that are transcribed, but are removed from within the primary gene transcript and rapidly degraded during maturation of messenger rna
discontinuous DNA assembly
as the 3' to 5' strand unwinds its 5' end is free so, the complement would be generated 3' to 5'. Except that can't happen, so as the DNA unwinds, replication of this strand is paused, until enough is free to start replication. Because of the nature of DNA, this is done in fragments (okazaki fragments)
stages of translation in order
initiation, chain elongation, and chain termination
Genetic experiment stages
DNA cleavage, production, cloning, ad screening
Preliminary vs. Secondary screening techniques
Preliminary screenings are antibodies ;
Secondary screening is molecular probes
Southern Blot Test
DNA is put into fragments and spread apart by gel electrophoresis.
Sticky Ends
Happens in stage ONE of GENETIC EXPERIMENT (It becomes sticky by result from the cut, can be used to pair up with other DNA fragments.)
Plasmids
Circular DNA or RNA molecules carrying only a few genes
1) fertility (bacterial)
2) Resistance (Antibodies)
restriction enzymes
DNA cut apart foreign DNA molecules "scissors"
DNA ligase
DNA "tape" can be used to splice together cut plasmids ad chromo fragments
DNA library
Total DNA constitutes a library. Bactria and yeasts are hosts.
DNA amplification
The production of multiple copies of a sequence of DNA. Repeated copying of a piece of DNA.
Cdna
Copied DNA
RFLPs
Restriction fragment length polymorphisms , they identify unique genetic fingerprints
transformation
the taking up of DNA from the fluid surrounding a cell.
transduction
the transfer of bacterial genes by a bacteriophage (a virus which can inject viral DNA into a bacterium.)
conjugation
transfer of plasmids (circular DNA, or RNA, molecules carrying only a few genes); it is replicated independently of the "main" chromosome;
there are two types: 1) Fertility "F" Plasmid
2) Resistance "R" Plasmid
PCR
Polymerase Chain Reaction - Uses several steps to split DNA into 2 strands, portions of which are then copied and reassembled into millions of double-stranded forms that can be separated from each other by gel electrophoresis. Heat to denature, Prime to copy.
Direction of movement (gel electrophoresis)
electrical charge
transcription starts at
starts at promoter
RFLP's are based
on where different enzymes cut DNA
Ribosomal =
Probe
3 stop codons, they
do not specify what amino acids they stop
Lagging =
discontinuous
A gene is a piece if DNA, DNA to proteins. =
encoded into proteins
Transcription - 3 different types of RNA molecules: r,m &t
Transcription - RNA polymerase
Portion which DNA is translated: =
Exons
RNA and DNA is complementary =
A to T/U and G to C
2 antiparell chains held together by
hydrogen bonds
Reserchers prefer _____ when working with human genes
cDNA
DNA copy enzymes to mRNA reverse transcriptase
is RNA to DNA
Different kinds of RNA transcribed in
in Nucleus (Nucleolus)
ATG - CGT
DNA
TAC - GCA
Codon
AUG - CGU
Anticondon
Conjunction 2: F+ bacteria transfer genes by
by Pili
Original DA strand to build a new strand
Semi-conservative method
mRNA leaves nucleolus and becomes a
a Ribosome
A to P to E is the way
the order is loaded onto the ribosomes.