Download Basic Biotechnology Review

Biotechnolgy
Basic Molecular
Biology
• Core of biotechnology
Began in 1940’s
• Scientists studying animal
and plant viruses
1953
• James Watson and Francis
Crick identified the
structure of DNA
1960’s
• The genetic code was
worked out
1970’s
• Restriction enzymes were
discovered.
Broad range of studies
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DNA-RNA
genetic engineering
cloning
gene therapy
recombinant DNA
gene splicing
Nucleotides
• Building blocks of nucleic
acid
• composed of three parts
–a phosphate molecule
–a sugar molecule
–a nitrogen base molecule
Sugar molecules
• ribose as in RNA
• deoxyribose as in DNA
Nitrogen bases
• five bases in RNA and
DNA
DNA
• Cytosine - C
• Thymine - T
• Adenine - A
• Guanine - G
RNA
• A, C, G &
• Uracil - U
• found only in RNA
• Substitutes for Thymine
Structure of DNA
• genetic material of the cell
- makes up the genes
• genes are organized in
chromosomes
Chromosomes
• make up the genetic info of
the cell or genome
The nucleotides…..
• ACT&G form two long
strands
• The strands are
complimentary
• Bases on one strand are
paired with those on the
other strand
Base Pairing
• A with T
• C with G
• ALWAYS this way!
1. The DNA Structure was
identified by…..
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A. Smith and Wesson
B. Watson and Edison
C. Watson and Crick
D. Hodges and Kadinger
2. Nucleotides are:
• A. building blocks of nucleic
acids
• B. building blocks of proteins
• C. sugar molecules
• D. high and low tides caused
by phases of the moon
3. The four bases in DNA include
Cytosine, Guanine, Thymine and
_____
• A. Adenoid
• B. Uracil
• C. Adenine
• D. Adipose
4. When was the structure of DNA
identified
• A. 1935
• B. 1948
• C. 1928
• D. 1953
Double Helix
• forms when the two strands
intertwine
• like a ribbon around a pole
Antiparallel
• The two strands run
antiparallel
• They face each other and
run in opposite directions
Strands run in different
directions
• one strand runs from 5’ to
3’
• the other strand runs 3’to
5’
Prime ends
• 3’ & 5’ are differentiated
by the arrangement of the
sugar on each nucleotide
• 5’ ends in a Phosphate (P)
• 3’ ends in a Hydroxide
(OH)
DNA Structure
• unique for three reasons
• complimentarity of the two
strands - base pairing
• variability of base
sequence along the two
linear strands
DNA Structure
• independence of the two
strands
–their ability to separate and
rejoin without destroying
the molecule.
DNA in Humans
• 6 billion base pairs in a
human cell
• 100 trillion cells in human
body.
• DNA in a human would reach
to the moon and back 250,000
times
Turns of the helix
• There are ten base pairs per
complete turn of the helix
• Distance of one complete
turn of the helix is 34 A (
Angstrums)
Functions of DNA
• carry genetic information
• express genetic
information
Express genetic info
• directs the synthesis of
proteins
• proteins determine the
traits of an organism
5. How many base pairs are in
each turn of the DNA helix
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A. 8
B. 10
C. 12
D. 11
6. The bases in DNA pair this way:
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A. A with T, G with U
B. A with U, T with C
C. C with G, T with U
D. A with T, C with G
7. The four bases found in RNA are
• A. cytosine, thymine, adenine,
guanine
• B. cytosine, thymine, uracil,
guanine
• C. cytosine, uragoof, adenine,
guanine
• D. cytosine, uracil, adenine,
guanine
Eukaryotic Cells
• having a true membrane
bound nucleus
• DNA of nucleus is stored
by wrapping it around five
proteins to form a
nucleosome.
Nucleosome
• forms the chromosome
• the genes are located along
the DNA molecule
• chromosomes occur in
pairs
8. The sequence of bases in a strand
of DNA is represented by TACCAG,
what would be the sequence in the
complementary DNA strand?
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A. TACCAG
B. UADDAG
C. ATGGTC
D. AUGGUC
9. What would be the sequence of
bases in RNA transcribed from the
sequence TACCAG?
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A. TACCAG
B. UACCAG
C. ATGGTC
D. AUGGUC
Prokaryotic Cells
• chromosome is not associated
with proteins
• exists as a single, circular
chromosome of double
stranded DNA.
• Also contain smaller circular
DNA called a plasmid
Plasmids
• can pass between bacteria
• are vehicles for introducing
new genes into bacteria in
nature and in the lab
Transcription
• Replication
• goes from the 5’ to the 3’
end of DNA
Reading DNA
• DNA is read from 3’ to 5”
Synthesis of DNA
• synthesized only in the 5’
to 3’ direction
• Cannot initiate synthesis of
a new strand - requires a
3’OH as a primer
Types of RNA
• messenger - mRNA carries
the code for a protein
Codon
• sequence of three bases
• each three bases represents
an amino acid
Transfer RNA
• tRNA
• carries appropriate Amino
Acid with it
• anticodon - pairs with the
codon
10. A codon is made up of ____
bases.
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A. three
B. four
C. five
D. eighteen
11. In RNA, Uracil pairs with__
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A. Cytosine
B. Guanine
C. Thymine
D. Adenine
Ribosomal RNA
• rRNA
• required for bonding to
occur by Amino Acids
• Ribosome has two parts
–big
–small