Ch 17-19 Flashcards
(27 cards)
Define introns & exons
introns are non-coding region of DNA & exons are coding region of DNA that codes for proteins
Describe initiation stage of transcription
After RNA polymerase binds to Promoter, DNA strands unwinds & polymerase initiates RNA synthesis at start point on DNA Template Strand. Start Codon is AUG
Describe elongation stage of transcription
RNA polymerase moves downstream, unwinding DNA & elongate RNA transcript 5’-3’
Describe termination stage of transcription
eventually, RNA transcript is released at stop codon & RNA polymerase detaches from DNA
Describe the function of splicesome
splices out introns from exons for processed mRNA. CAP & Poly AAAA tail is added which allows mRNA to leave nucleus
What are Ribosomes made of.
Ribosomal RNA & Proteins arranged as small & large subunit
Define anticodon
tRNA carries amino acid that is determined by mRNA codon & anticodon on tRNA to ribosome
Describe function of E, P, & A sites in mRNA translation into polypeptides
- E is the exit site where tRNA exits the ribosome
- P is the site that holds tRNA carrying growing polypeptide chain
- A is the site that holds tRNA carrying next amino acid for addition to chain.
What is the function of the Signal Sequence on the mRNA and the Signal Recognition Protein?
The signal sequence is translated into signal peptide after mRNA binds to ribosome. The SRP has high affinity for Signal Peptide that binds to it. This signal complex bound to the ribosome will now bind to SRP receptor on rough ER & protein being made is translocated into ER, to soon be transported with a transport vesicle to the Golgi Apparatus
Define Silent Mutation
a point mutation in DNA resulting in a codon for the same amino acid as the original codon, thus making a normal protein.
Define Nonsense Mutation
a point mutation in DNA resulting in a stop codon forming right after the start codon
Define Missense Mutation
a point mutation in DNA resulting in a codon that codes for a different amino acid
Define Frameshift Mutations
when a base pair is inserted or deleted, changing reading frame of codons
Define gene expression
proteins that are being made in any particular cell type
Define Operons
series of genes for a specific pathway controlled by a promoter & operator. The operator controls whether RNA Polymerase can bind to the promoter to start transcription. Repressor proteins can turn off the operator so that RNA polymerase cannot bind to the promoter
What are the differences between the lytic and lysogenic cycle of a virus?
- lytic cycle-virus reproduces rapidly & kills host cell
* lysogenic cycle-virus reproduces slowly & does not kill host cell
Describe the steps of Animal Cloning
- Remove haploid nucleus from a donor egg cell
- Add diploid somatic cell nucleus
- give donor egg with cell nucleus a little electric shock with microelectrode. The egg thinks it has been fertilized & starts mitosis
Name two Vectors used to import foreign genes into bacteria, plants, & animals
Plasmids & Viruses made harmless
What are genetic markers and how are they used for Fingerprint DNA?
DNA cutted into fragments by restriction enzymes that are run on gel. Genetic markers are unique to each person since no 2 ppl have identical DNA. Thus can be used in DNA fingerprint analysis
What is the difference between pluripotent & multipotent stem cells?
Pluripotent stem cells are embryonic stem cells that can form any cell type. Multipotent stem cells are more limited, but can form many cell types. These are adult stem cells found in bone marrow & umbilical cord stem cells
Name two vectors used to make transgenic (recombinant) organisms?
Plasmids from bacteria & Harmless Virus Particles
Define plasmids
small rings of DNA found in some prokaryotes, usually encode antibiotic resistance in bacteria
Embryonic stem cells are derived from what?
the blastula/blastocyst
Define blastula
when a fertilized egg divides & forms a hollow ball of cells. This is the stage that implants in the uterus. The inner cell mass forms the embryo & the outer layer of cells will form the placenta.
