Unit 5- Molecular Genetics Flashcards
3 parts of a nucleotide in RNA
- ribose sugar
- nitrogenous base
- phosphate
4 nitrogenous bases in RNA
- uracil
- adenine
- guanine
- cytosine
What are the complements of nucleic bases in RNA?
- adenine & uracil
- guanine & cytosine
Why does protein synthesis take place?
To create proteins needed for you body through RNA
3 main differences between DNA & RNA
DNA- thymine
RNA- uracil
DNA-deoxyribose
RNA- ribose
DNA- double helix
RNA- single twisted strand
3 types of RNA
- messenger RNA (mRNA)
- ribosomal RNA (rRNA)
- transfer RNA (tRNA)
Reactants and products of protein synthesis
Reactants
- DNA/ RNA bases
Products
-amino acids to make proteins
Genotype
The genetic makeup of an organism
(The base sequences)
Ex) ACGTATCG
Phenotype
The physical traits of DNA.
Ex) brown hair; green eyes
Where does transcription occur?
In the nucleus
RNA polymerase
Transcription enzyme that links RNA nucleotides together
RNA splicing
After transcription, introns (non coded regions are taken out and exons (expressed regions) are put together
Cell differentiation
increasing specialization in structure and function of cells
Stem cells
Cells that remain undifferentiated and can change to various types of cells
Why is cell differentiation important?
different types of cells create functioning organisms
What are the two types of stem cells?
Embryonic & after birth stem cells
Embryonic stem cells
Highly versatile- they can become any cell they want
After birth stem cells
Unable to make the full range of cells. But can still change to different cells
Stem cell controversy
The ways that stems cells are squires may be an ethical/ moral issue
Gene expression
transcription and and translation of genes into proteins
What are the ways to retrieve stem cells for research?
- Embryos
- bones
- umbilical cords
GMO
Genetically modified organisms
Ex) corn, leaner meat, Better wool
Created to achieve the consumer’s wants and needs
How are GMO’s created
Insert a gene from the same species of animal to another
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.
Recombinant DNA technology
Combining genes from different sources (same or different species) into one single DNA molecule
DNA fingerprinting
The banding pattern produced by gel electrophoresis and restriction fragments
(Everyone has a different DNA fingerprint)
Biotechnology
The use of organisms to perform practical tasks for humans
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
structure of RNA
single twisted strand
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 RNA splicing occur
in the nucleus
before it leaves to go to the ribosome
intron
a non coded region of RNA
exon
a coded region in RNA
translation
changing RNA to amino acids to make proteins
what kind of RNA changes codons to amino acids?
tRNA
it read the codon and “translates”
reactants and products of translation
reactant- mRNA
product- amino acids (proteins)
where does translation occur
in ribosomes which are in the cytoplasm
what kind of RNA makes up codons
rRNA
what is the purpose of a codon
a three base sequence in mRNA to be read to match with amino acids to make proteins
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
mRNA
messenger RNA
- the primary sequence of bases after transcription
- carries the codons out of the nucleus and into the cytoplasm
rRNA
reibosomal 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)
what is attached to an anticodon
the amino acids
what is the purpose of the genetic code table?
to “translate” what amino acids that codons code for
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
examples of mutagens
most common is high energy radiation (from x- rays)
can also be chemicals similar to normal DNA bases
plasmids
small, circular DNA molecule found in bacteria that is separate from the bacterial chromosome
restriction enzymes
enzyme that cuts sugar- phosphate bonds in the DNA backbone at specific points within particular nucleotide sequences in DNA
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
transgenic
GMO whose source of new genetic material is a different species (got new DNA from a different species)
GMO controversy
- threat of accidentally creating “super weeds”
- threat of significant health & environmental risks
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
