Molecular Genetics Flashcards
Define gene
- A sequence of nucleotides that code for 1 polypeptide
- A segment of DNA
- A unit of inheritance
Describe the structure of DNA
DNA:
- Consists of 2 strands of DNA molecules twisted around each other in a double helix structure
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- The basic unit of DNA Is a nucleotide consisting of 1 phosphate group, 1 nitrogenous base, and 1 deoxyribose sugar.
- Many nucleotides join tgt via covalent bonds to form a polynucleotide.
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- Polynucleotide strands run in anti-parallel directions
- and are joined tgt based on the rule of complementary base pairing:
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- Adenine pairs with Thymine via 2 Hydrogen bonds
- Cytosine pairs with guanine via 3 Hydrogen bonds
Why do some cell have X-shaped chromosomes
They are just about to carry out mitosis so their chromosomes double
Making transgenetic bacteria that produces insulin
- Obtain the fragment of DNA in human chromosome that contains the insulin gene
- Cut the insulin gene using a restriction enzyme to produce 2 sticky ends
- A sticky end is a single strand of DNA bases - Obtain a DNA plasmid from a bacterium cell
- Use the same restriction enzyme to cut the bacterium plasmid and produce 2 complementary sticky ends
- Use DNA ligase to join the insulin gene w/ the bacterium plasmid forming a recombinant plasmid
- Mix the recombinant plasmid & bacterium cell tgt
- Apply temporary heat shock to open up the pores of the bacterium cell membrane so the recombinant plasmid can enter
—— - Transgenetic bacteria is produced & grown in fermenters at optimum temperature, pH & w/ nutrients
- Insulin protein from transgenetic bacteria must be extracted & purified b4 use
Benefits of genetic engineering & explanations
- ## Health Low costs of producing medicines
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Econ & environ Production of crops that produce toxins to kill pests
- No need to use pesticides that cost $$
- Less pesticides that are harm to environment are used. Like pesticides that cause euthrophication
Ethical & social implications
- Genetic engineering technology may only be accessible to wealthier people and not poorer people.
- Greater divide between the rich and poor
- - For antibiotics Antibiotic gene may be transferred to bacteria, making diseases caused by bacteria harder to treat