unit 5- molecular genetics (11&13) Flashcards
3 main differences between DNA & RNA
DNA- thymine
RNA- uracil
DNA-deoxyribose
RNA- ribose
DNA- double helix
RNA- single twisted strand
4 nitrogenous bases in RNA
- uracil
- adenine
- guanine
- cytosine
What are the complements of nucleic bases in RNA?
- adenine & uracil
- guanine & cytosine
what happens during transcription?
DNA is turned into RNA
- mRNA is created (like DNA replication, but with only one strand & with uracil instead of thymine)
Where does transcription occur?
In the nucleus
translation
changing RNA to amino acids to make proteins
reactants and products of translation
reactant- mRNA
product- amino acids (proteins)
where does translation occur
in ribosomes which are in the cytoplasm
3 parts of a nucleotide in RNA
- ribose sugar
- nitrogenous base
- phosphate
3 types of RNA
- messenger RNA (mRNA)
- ribosomal RNA (rRNA)
- transfer RNA (tRNA)
codon
in RNA, a three-base “word” that codes for one amino acid
what kind of RNA makes up codons
rRNA
3 stop codons
UAA-UAG-UGA
to stop the ribosome from continuing the sequence and messing up the protein being made
start codon
AUG
used to signal where a new amino acid sequence should start
anticodons
a triplet of bases that is complementary to the codon in mRNA
what type of RNA makes up anticodon
tRNA
what is the purpose of the genetic code table?
to “translate” what amino acids that codons code for
mRNA
messenger RNA
- the primary sequence of bases after transcription
- carries the codons out of the nucleus and into the cytoplasm
rRNA
ribosomal RNA
a type of RNA made up to create the ribosome which is needed to change the mRNA into amino acids
tRNA
transfer RNA
the anticodon and directs the amino acid to match up with the codons (anticodon and amino acids are connected together)
mutation
any change in the nucleotide sequence of DNA
3 types of mutuations
- substitution
- deletion
- insertion
substitution (mutation)
switching out one base for another
Ex) aCtgtca -> aTtgtca
deletion (mutation)
taking out a base of the sequence
Ex) aCtgtca -> a_tgtca
insertion (mutation)
adding in a base into a sequence
Ex) actgtca -> aGctgtca
mutagen
physical or chemical agent that causes mutations
Bacteria
- used to introduce new genes into other organisms (plasmids)
- mass production of useful genes and proteins
- make medicine (human benefit)
- can make a lot very fast (easily accessible
Biotechnology
The use of organisms to perform practical tasks for humans
restriction enzymes
enzyme that cuts sugar- phosphate bonds in the DNA backbone at specific points within particular nucleotide sequences in DNA
plasmids
small, circular DNA molecule found in bacteria that is separate from the bacterial chromosome
when are restriction enzymes used?
to cut apart foreign DNA to move fragments around
Cloning DNA
1) restriction enzymes cut plasmids in one place and DNA in many places
2) the DNA fragment “sticky end” comes into the plasmid and connects according to the base pairing
3) DNA ligase joins the pieces- forming a recombinant DNA plasmid
4) bacteria takes in the recombinant plasmid
5) cell division results in many recombinant plasmids`
PCR
polymerase chain reaction
technique that makes many copies of DNA without using a living organism
things needed for PCR
- targeted DNA
- DNA polymerase
- primers
- nucleotides
process of PCR
put all the ingredients in a test tube, then heat it up to create the designated amount of DNA
Gel electrophoresis
Techniques for sorting DNA fragments
This creates the DNS fingerprint
How does gel electrophoresis work?
The DNA is charged slightly negative, so when electricity charges the gel, the DNA fragments move through the gel. The smaller the fragment, the further it goes.
DNA fingerprinting
The banding pattern produced by gel electrophoresis and restriction fragments
(Everyone has a different DNA fingerprint)
