DNA (fuck) Flashcards
1
Q
Frederick Griffith
A
1928
Living bacteria get “transformed” by dead bacteria
2
Q
Hershey and Chase
A
1952
Radioactivity, bacteria and viruses prove DNA is genetic material
3
Q
Nucleotide
A
the monomer unit of DNA and RNA
contains- nitrogenous base, 5-carbon sugar, phosphate group
4
Q
DNA and RNA are…
A
polymers of nucleotide
5
Q
backbone
A
made of alternating sugar and phosphate molecules, bonded covalently
6
Q
N-Bases __________ from sugars
A
extend
7
Q
DNA sugar
A
deoxyribose
8
Q
RNA sugar
A
ribose
9
Q
What takes place when forming the bond
A
dehydration reaction
10
Q
Franklin and Wilkins
A
X-ray crystallography reveals the shape of DNA molecule
11
Q
Franklin and Wilkins found out that the DNA molecule’s shape is a __________________.
A
double helix
12
Q
Watson and Crick
A
credited with discovery of DNA structure in 1953 after seeing Franklin’s x-ray
13
Q
Chargaff
A
discovers base pairing law
14
Q
Base pairing law (Chargaff’s law)
A
A=T
G=C
15
Q
Thymine and cytosine are _________________.
A
pyrimidines
16
Q
Adenine and Guanine are _________________.
A
purines
17
Q
DNA
A
two polynucleotide chains joined by hydrogen bonding between N-bases, twisted in a helical shape
18
Q
The ___________________ backbone is on the outside.
A
sugar-phosphate
19
Q
The nitrogenous bases are ______________________ to the backbone in the interior.
A
perpendicular
20
Q
Replication must take place before ______________.
A
cell division
21
Q
DNA replication is ______________________.
A
semiconservative
22
Q
semiconservative
A
Each resulting piece is half old, half new
23
Q
DNA opens to produce a ____________
A
bubble
24
Q
Replications proceeds in both….
A
directions
25
when bubbles merge
replication ends
26
DNA strands are ____________________
antiparallel
27
antiparallel
run in opposite direction
28
DNA helicase
unwinds and unzips DNA molecule
29
DNA polymerase
adds nucleotides to a growing chain
30
DNA ligase
joins small fragments into a continuous chain
31
DNA vs RNA
RNA never has paired nucleotides
32
mRNA (messenger)
takes message from nucleus to cytoplasm
| carries only one protein worth of information
33
rRNA (ribosomal)
composes ribosome subunits
34
gene
a unit of heredity information that directs the synthesis of a specific protein
35
protein syntesis
the production of a polypeptide chain from a DNA sequence
36
transcription
DNA to mRNA (same language), in nucleus
37
translation
mRNA to protein (diff. language), in cytoplasm on ribosome
38
Transcription // step 1
DNA molecule is unzipped
39
Transcription // step 2
mRNA molecule is produced
40
elongation // with step 2 of transcription
RNA polymerase catalyzes reaction
41
Transcription // step 3
mRNA molecule leaves nucleus, DNA zips
42
Transcription // step 4
mRNA associates with ribosome
43
Transcription // step 5
Ribosome reads mRNA codons, brings in complementary tRNA anticodons carrying amino acids
44
codons are like..
DNA words
45
Transcription // step 6
Ribosome connects amino acids via peptide bonds to form polypeptide
46
The translation process incorporates ______ _________________ _____________ ___________________ in the precise sequence dictated by the three-base codons from and alphabet of four bases.
20 different amino acids
47
triplet code
three nucleotides specify one amino acid
48
How many total codons?
64
49
_________ codons correspond to amino acids
61
50
AUG codes for _________________ and signals the start of transcripition
methione
51
_____ "stop" codons signal the end of translation
3
52
initiation
RNA polymerase binds to promoter sequence- helix unwinds and transcription starts
53
termination
RNA polymerase reaches terminator sequence and detaches from DNA
54
mRNA has interrupting sequences called __________
introns; separating the coding regions called exons
55
RNA splicing
removal of introns and joining of exons to produce a continuous coding sequence
56
Initiation in translation
start codon initiates building of polypeptide
57
AUG
methionine
58
Termination in translation
stop codon terminates building of polypeptide
59
elongation in translation
amino acids are added by ribosome to grow the chain
60
mutation
change in the nucleotide sequence of DNA
61
mutations are caused by
base substitutions
deletions or insertions
spontaneous errors
environmental mutagens (chemicals, radiation, etc)
62
gene cloning
producing multiple identical copies of a gene carrying piece of DNA
63
step 1 // gene cloning
Donor DNA is isolated and cut
64
step 2 // gene cloning
plasmid DNA isolated and cut
65
plasmid
circular DNA found in bacteria
66
step 3 // gene cloning
create recombinant DNA by mixing donor DNA with plasmid
67
recombinant DNA
DNA molecule w/DNA from two different sources.`
68
products of DNA technology
vaccines
| ...
69
genetically modified
organisms contain one or more genes introduced by artificial means
70
transgenic organisms
contain at least one gene from another species
71
concerns related to GM organisms
can introduce allergens into the food supply
| may spread genes to closely related organisms
72
GMO's are ________ reduced
highly
73
__________ ________________ address the safe use of biotechnology
regulatory agencies
74
gene therapy
aims to treat a disease by replacing a faulty gene with a properly functioning one
75
controversial:
is it right to modify the genes of a human?
Is it safe? (SCID trials)
Are results promising?
76
So far, benefits have been _______ in gene therapy.
slow
77
DNA profiling involves
collecting a DNA sample
amplifying the amount of DNA
cutting and sorting DNA fragments
Analyzing the pattern of bands caused by repeat sequences
78
collecting a DNA sample
must be from cells that contain DNA: Blood (white, not red), bone, hair follicle (not hair protein), skin, ,nerve, cheek cells, etc.
79
Polymerase chain reaction (PCR)
a method of amplifying (copying) a specific segment of a DNA molecule
80
PCR process // step 1
denature DNA with heat
81
denature DNA with heat // causes
DNA strands unzip and become single stranded
82
PCR process // step 2
primers attach as sample cools down
83
Primers are ___________________ to DNA and __________________ the sequence to be copied.
complimentary; identify
84
Primers are ________________
man-made
85
PCR process // step 3
DNA polymerase attaches new DNA nucleotides, resulting in copy of DNA molecule
(often isolated from bacteria in hot springs (heat resistant))
86
In the PCR process, steps are repeated over and over to create a ________ ____________ of copies
large number
87
DNA fragments are cut with ______________ ________________ and sorted by size by gel electrophoresis
restriction enzymes
88
Gel electrophoresis process : 1
DNA samples are placed at one end of a porous gel
89
Gel electrophoresis process: 2
Electrical current is applied and negatively charged DNA molecules move from the negative electrode toward the positive electrode.
90
Short tandem repeats (STRs)
genetic markers used in DNA profiling
short DNA sequences that are repeated many ties in a row at the same location
The number of repeats determines the length of the fragment
91
Only about ___% of our DNA codes for proteins
2
92
Current standard for DNA profiling is to analyze ____ different STR sites
13
93
Forensics
evidence to show guilt or innocence
94
establishing family relationships
paternity analysis
95
identification of human remains
After tragedies such as September 11, 2001, attack on the World Trade Center
96
species identification
Evidence for sale of products from endangered species
97
short DNA sequences that are repeated many times in a _______ at the same location
row
98
the number of _______________ determines the length of the fragment
repeats
99
genomics
the study of an organism's complete set of genes and their interactions
100
many genomes have been _________________ and ___________________
investigated; completed
101
goals of the human genome project (HGP)
determine the nucleotide sequence all DNA in the human genome
identify the location and sequence of every human gene
102
expected future benefits of the HGP
"customized" pharmaceuticals tailed to specific patients
opened discussion for ethical concerns
improved agriculture and environmental management
enhanced ability to identify causes of genetic disorders.
103
proteomics
study of the complete set of proteins specified by a genome
104
the human proteome contains approx.
100,000 proteins
105
epigenetics
study of how environmental factors affect gene expression
106
gel electrophoresis
sorts DNA molecules by size
107
gel electrophoresis process
DNA samples are placed at one end of a porous gel
108
transgenic organism
organism that has had a new gene transferred to it
109
restriction enzymes
cut DNA or specific sequences
| enzyme binds to DNA at restriction site
110
genetically modified
contain 1 or more genes introduced by artificial means.
