Biology Topic 8 : Recombinant DNA technology

What is the genetic enfineering?

Deliberately modifying an organism by removing a gene and transferring it into another organism

What is the goal of genetic engineering?

To make the recipient organism express the desired gene

What are the three ways to obtain a gene?

Restriction enzymes, reverse transcriptase or gene machine

What are endonucleases?

Enzymes that cut DNA at specific base sequences

Where are restriction enzymes found?

Bacteria

what is restriction enzymes natrual role?

To defend bacteri by cutting viral DNA

What is a restriction site?

Specific base sequence where a restriction enzyme cuts

What are sticky ends?

DNA ends where one strand is longer, allowing easy base pairing

What are blunt ends?

DNA ends cut straight across with no overhang

Why are sticky ends useful?

They easily form hydrogen bonds with complementary sticky ends

How cna blunt ends be made usable?

By adding extra nucleotides to

What is reverse transcriptase used for?

To make cDNA for mRNA

Why use mRNA instead of DNA?

mRNA has no introns, so the cDNA is clean and usable

Where dies reverse transcriptase come from?

Retroviruses

What happens after cDNA is made?

DNA polymerase makes it double stranded

Why is this method useful?

Specialised cells make lots of mRNA for specific protines

What is a gene machine?

A computer controlled system that build genes artifically

How does a gene machine work?

IT uses the genetic code to design and assemble nucleotide sequences

What happens after short DNA fragments are made?

They are joined together and inserted into a vector

What is artificial synthesis used for?

Creating novel genes, vaccine components and even synthetic genomes