12 molecular genetics Flashcards
can u inherit 1/2 a gene?
no.
- a gene, unit of inheritence, specific sequence nucleotides, codes for single polypeptide
DNA molecule vs chromosome
chromosome: untangled DNA molecule
describe DNA
- DNA MOLECULE made 2 strands polynucleotides held together
double helix structure,** hydrogen bonds** - Each POLYNUCLEOTIDE STRAND made basic unit nucleotides
- NUCLEOTIDE MOLECULE made three components: phosphate group, deoxyribose, 1 of 4 different nitrogenous base
- 4type nitrogenous base: adenine, thymine, cytosine, guanine
- rule complementary base pairing
- A always pair w/ T, C alw pair w/ G, 1:1
- phosphate group, deoxyribose, consecutive nucleotides, arranged in a
alternating pattern, forming sugar phosphate backbone.
WHY IT IS CALLED AGCT?
Purin: A (2 hydrogen bonds), G (3 hydrogen bonds) (2 rings)
Pyrimidin: C (2 hydrogen bonds), T (3 hydrogen bonds) (** 1 ring**)
2 rings bond w/ 1 ring
2 bond fit into 2 bonds
relationship
chromosome
DNA molecule
gene
- chromosome -> single molecule, deoxyribonucleic acid, highly coiled, condensed struct
- DNA molecule -> many gene
- gene -> unit of inheritance, made of sequence of nucleotides, code 1 polypeptide
DNA funct (specific)
- carries genetic info -> genetic code
- each gene, unit inheritance, sequence nucleotides, code, single polypeptide
- gene, transcription -> single mRNA molecule, in nucleus
- mRNA molcule diffuse out, nucleus -> cytoplasm
- ribosomes translate mRNA molecule -> synthesise 1 specific polypeptide
genetic engineering
technique
transfer genes
1 organism -> another
transgenic organism
organism, contain genes, at least 2 different species
produced, artificial process, such as genetic engineering
transgenic plant example
1. how produce
2. benefits
- genetically modified organism,
- Bt-corn, gene from bacterium
- enable produce own insecticide
how extract DNA from human -> insulin produced, bacteria?
- Lyse human cells, cut out insulin gene, restriction enzyme, obtain sticky ends,
- Lyse bacteria cells, retrieve, cut plasmid w/ same restriction enzyme, obtain complementary sticky ends
- mix extracted insulin gene w/ plasmid, add DNA ligase, join insulin gene, plasmid
- mix recombinant DNA, bacteria, apply temporary heat/electric shock, bacteria take in recombinant DNA
- transgenic bacteria, grown in fermenters, mass production insulin
- lyse bacteria cells, obtain insulin, extract, purify
5 benefits genetic engineering/GMO
- safe, rapid drug production, availibility, affordability
- increase resistance 2 harsh env, improve food security
- increase crop quality (), reduce nutritional deficiencies
- less use chemical herbi/insectcides, reduce pollution, cost farming
- allow introduction, desirable characteristic, not present, gene pool
selective breeding disadv compared to GMO
cases where selective breeding, could not produce desired phenotype
3 env. harms genetic engineering/GMO
1 introduce desired genes, KO other genes, reduce biodiversity within GMO population
2 possible cross pollinate/gene transfer, contaminate wild () gene pool
- weeds resistant herbicides
- pathogens fast-growing
3 GM () modified, produce (), may unintentionally produce toxins, when consumed -> animals, harm animals, higher trophic lvls, reduce biodiversity
4 ethical, social considerations
GMO
- ANIMAL CRUELTY insertion gene -> chromosome, disrupt other genes, genetic diseases + death, quality of life reduced
- GM () modified, produce (), may unintentionally produce toxins, when consumed -> allergic reaction/unknown long-term effect
- cost of tech -> inaccessible, poorer communities
- patented, exclude resource tight farmers
3,4 -> not inclusive, medical, agricultural soln.
carrier vs heterozygote
always use heterozygote
(carrier = heterozygous for a disease)
mutation must write…
- example for Chromosomal mutation
- example for change of sequence of nucleotides mutation
