1. 12-02-09 Notes
Insulin (cont’d)
The insulin production problem:
-create a gene without introns, do not need to process mRNA
-c-DNA
Making c-DNA
-If a cell is making a protein there will be mRNAs for that protein
in the cytoplasm
-introns removed, DNA moves out into ribosomes where it is
replicated
-use mRNA to make a DNA copy of the mRNA strand
-Extract the mRNA and make a DNA copy with reverse
transcriptase.
-retroviruses carry information as RNA
-Reverse transcriptase is an enzyme found in retroviruses like HIV—viral
RNA enters host cell
-complimentary base pairs with RNA, creates DNA
-then the new single strand of DNA is used as a template to make the
other side of the DNA molecule
-No introns present, introns locked up in ribosomes using c-DNA
-most
Agricultural uses of DNA technology
-Due to cell wall, plant cells are easily separated
-single cell can grow
-in right environment [temperature, hormones, etc]
-divide by mitosis, create new plant
-totipotency – in plants, not animals
Ti (tumour inducing) Plasmid Vector
-Agrobacterium tumefacies
--causes gnarles on sides of tree bases, protecting
internal bacteria
DNA Technology Methods
-Gel Electrophoresis
-PCR – Polymerase Chain Reaction
-Restriction Fragment Length Polymprphisms (RFLP’s)
-DNA Sequencing
RFLP Analysis (Restriction Fragment Length Polymorphisms)
-mutation in restriction site
-2nd person’s DNA = different.

2. Gel Electrophoresis
-Wells in the gel are filled with DNA samples which were cut into
fragments by a restriction enzyme
-Electric current goes through gel, fragments of DNA attracted to
positive end of gel, repelled from negative end, attracted to
positive end.
-Short pieces move through gel rapidly, long ones move slowly
-larger length, slower transport
DNA Fingerprint
-Comparison of restriction fragments that are made from DNA
fragments separated by restriction enzymes
PCR Polymerase Chain Reaction
-Copies of small DNA samples can be made.
-Make many copies of small amount of DNA so there is enough
to work with
Practical Applications of DNA Technology
-Diagnosis of Diseases
-Human Gene Therapy
-Pharmaceutical Products
-Forensic Uses of DNA Technology
-Environmental Uses of DNA Technology
-Agricultural Uses of DNA Technology
Chapter 24 – page 485
The Immune System
Nonspecific Defences
Skin
-Skin glands secrete enzymes
Mucus membranes
-Digestive system – acids, enzymes
-Respiratory system – cilia
Phagocytes
-White blood cells – phagocytic, engulf bacteria and dead cells
-Neutrophils
-Monocytes