Chapter 8 - Technology used to treat disease Flashcards
what is DNA
Found in the nucleus, mitochondria and cytosol. Consists of 2 strands of nucleotides (deoxyribose sugar, phosphate group and a nitrogenous base). Twisted in a double helix, bases attached by hydrogen bonds. The order of the 4 bases (A, T, C, G) is the genetic info that determines the structure and function of the cell
Artificial selection
Humans select desired traits and choose parents based on these traits. Slow and inefficient as genes are passed on by chance and have to wait for next generation to mature before knowing outcome. Also called selective breeding
Genetic engineering
Procedures used to produce recombinant DNA. involving introducing DNA into a cell from a different type of organism. Also known as recombinant DNA technology
Recombinant DNA
synthetic DNA made by inserting genes from one source into a DNA molecule from a different source
GMO
Genetically Modified Organism, produced by genetic engineering
Transgenic organism
Organism that has had DNA from another species introduced into it artificially. All transgenic organisms are GMO’s, but not all GMO’s are transgenic.
example of a transgenic organism
Golden rice. Transgenic organism produced by introducing a gene from maize and a bacterium found in soil into rice. Allows rice to produce beta carotene which the human body can use to synthesise vitamin A
who invented the recombinant DNA technique and when
Stanley Norman Cohen and Herbert Boyer in 1973
cohens and boyers technique
Isolate and amplify genes or DNA segments and insert them into bacterial cell, creating a transgenic bacterium. The introduced genes become part of the transgenic organism’s DNA and is passed to the next generation
two steps for genetic engineering to be possible
- gene for desired trait must be identified and then isolated
- DNA receiving the gene must be ‘opened’, then added to the recipient and joins its DNA
Bacteriophage
A virus that infects bacteria
Recognition site
Specific sequence of nucleotide at which a restriction enzyme cuts a strand of DNA. 4-8 base pairs long
Restriction enzyme
enzyme that cuts strands of DNA at a specific sequence of nucleotides (recognition site). Examples of endonucleases
Endonucleases
enzyme that breaks a nucleic acid within the strand by separating two nucleotides
What are the two types of cuts and ends that restriction enzymes can produce
- Straight cut (clean break across two strands of DNA) producing blunt ends (both strands terminate in a base pair, no overhang, not specific)
- Staggered cut (fragments of DNA with unpaired nucleotides) producing sticky ends (overhanging complementary bases, is specific, cut at different positions on strand)
Palindromic
Sequence that reads the same forward and backwards. recognition sites are palindromic
two factors that contribute to the type of cut
- Recognise a certain base sequence
- Cut at a certain point
DNA ligase
An enzyme capable of combining two small components of single stranded DNA into one single structure
Ligation
The process of joining short strands of DNA during replication
how does DNA ligase work
By joining the phosphate group at the end of one strand to the sugar molecule at the end of another strand
Vector
A bacterial plasmid or other agent used to transfer genetic material from one cell to another
what are the steps to producing an organism with recombinant DNA
- Identifying the desired gene
- Using restriction enzyme to cut the DNA on either side of the gene
- Using the same restriction enzyme to cut the DNA of the vector
- Adding the desired gene to the vector
- Using DNA ligase to join the two sections of DNA