BIOC0001 - MOLECULAR BIOLOGY EXAM QUESTIONS
AND ANSWERS WITH COMPLETE SOLUTIONS VERIFIED
genetic engineering
The direct manipulation of genes for practical purposes using biotechnology
recombinant DNA
combining two or more pieces of DNA that would normally not be found together using
artifical means
vector (recombinant DNA)
a vehicle used to transfer genetic material to a target cell
restriction enzymes
bacterial defense mechanism; recognises a short sequence of DNA as target for
cleavage; various enzymes have different consensus sequences; can create 3# or 5#
overhang or blunt ends; compatible sticky ends can bind together
Plasmids
found in bacteria; extrachromosomal, circular DNA; often contains genes for antibiotic
resistance or toxin production; replicate autonomously and independent of bacterial
DNA; have been modified to use in DNA manipulation
Ligase
connects DNA fragments/reestablishes phophodiester-bond
recombinant DNA process
,restriction enzymes cut at specific sequence; complementary sticky ends of two DNA
strands bind together; Ligase reconnects bonds
Recombinant DNA cloning
DNA fragment to be cloned inserted into plasmid; mix bacteria with recombinant
plasmid with new bacterial culture; after some time, expose culture to an antibiotic that
the recombinant plasmid has an resistance gene against; only cells that adapted the
plasmid will survive
types of vectors
Plasmid (20 kb); phage (25 kb); Cosmid (45 kb); P1 phage (100 kb); BAC (bacterial
artificial chromosome, 300 kb); YAC (Yeast artificial chromosome, 1000 kb)
transient vs stable plasmid
transient - plasmid stays in form of plasmid when adapted by a cell --> can be lost;
stable - plasmid is integrated into DNA
Electrophoresis
A process where DNA fragments are separated according to size using electrical
charges
Electrophoresis process
electric current applied. One end of gel is positive while the other end of gel is negative.
samples migrate to positive or negative pole , according to size, smaller migrate faster,
larger migrate slower (thus separating them), subject to autoradiography or incubate
with fluorescent dye
Southern Blotting Technique
, A procedure used to isolate and identify DNA fragments from a complex mixture. The
isolated, denatured fragments are transferred from an agarose gel (electrophoresis) to a
nitrocellulose filter (capilarry action in an alkaline solution transfers DNA from gel to
paper) and identified by hybridization with oligonucleotide probes.
DNA
deoxyribonucleic acid; storage of genetic information; double-helix structure;
Heteropolymer with four different nucleotides (AGTC)
RNA
ribonucleic acid; working copy; single stranded, heteropolymer from 4 different
nucleotides (GAUC)
Polymer
A long molecule consisting of many similar or identical monomers linked together.
Polymerisation
a chemical reaction joining monomers in long chains to form a polymer.
Bases
Adenine, Thymine(/Uracil), Cytosine, Guanine
pentose sugars
ribose and deoxyribose
nucleosides
base + sugar
nucleosides + phosphate
nucleotide
Polynucleotides
AND ANSWERS WITH COMPLETE SOLUTIONS VERIFIED
genetic engineering
The direct manipulation of genes for practical purposes using biotechnology
recombinant DNA
combining two or more pieces of DNA that would normally not be found together using
artifical means
vector (recombinant DNA)
a vehicle used to transfer genetic material to a target cell
restriction enzymes
bacterial defense mechanism; recognises a short sequence of DNA as target for
cleavage; various enzymes have different consensus sequences; can create 3# or 5#
overhang or blunt ends; compatible sticky ends can bind together
Plasmids
found in bacteria; extrachromosomal, circular DNA; often contains genes for antibiotic
resistance or toxin production; replicate autonomously and independent of bacterial
DNA; have been modified to use in DNA manipulation
Ligase
connects DNA fragments/reestablishes phophodiester-bond
recombinant DNA process
,restriction enzymes cut at specific sequence; complementary sticky ends of two DNA
strands bind together; Ligase reconnects bonds
Recombinant DNA cloning
DNA fragment to be cloned inserted into plasmid; mix bacteria with recombinant
plasmid with new bacterial culture; after some time, expose culture to an antibiotic that
the recombinant plasmid has an resistance gene against; only cells that adapted the
plasmid will survive
types of vectors
Plasmid (20 kb); phage (25 kb); Cosmid (45 kb); P1 phage (100 kb); BAC (bacterial
artificial chromosome, 300 kb); YAC (Yeast artificial chromosome, 1000 kb)
transient vs stable plasmid
transient - plasmid stays in form of plasmid when adapted by a cell --> can be lost;
stable - plasmid is integrated into DNA
Electrophoresis
A process where DNA fragments are separated according to size using electrical
charges
Electrophoresis process
electric current applied. One end of gel is positive while the other end of gel is negative.
samples migrate to positive or negative pole , according to size, smaller migrate faster,
larger migrate slower (thus separating them), subject to autoradiography or incubate
with fluorescent dye
Southern Blotting Technique
, A procedure used to isolate and identify DNA fragments from a complex mixture. The
isolated, denatured fragments are transferred from an agarose gel (electrophoresis) to a
nitrocellulose filter (capilarry action in an alkaline solution transfers DNA from gel to
paper) and identified by hybridization with oligonucleotide probes.
DNA
deoxyribonucleic acid; storage of genetic information; double-helix structure;
Heteropolymer with four different nucleotides (AGTC)
RNA
ribonucleic acid; working copy; single stranded, heteropolymer from 4 different
nucleotides (GAUC)
Polymer
A long molecule consisting of many similar or identical monomers linked together.
Polymerisation
a chemical reaction joining monomers in long chains to form a polymer.
Bases
Adenine, Thymine(/Uracil), Cytosine, Guanine
pentose sugars
ribose and deoxyribose
nucleosides
base + sugar
nucleosides + phosphate
nucleotide
Polynucleotides
