Replication
Transcription
Translation
Gene regulation
More gene stuff
100
Phase of DNA replication in the cell
S phase in Interphase
100
Why is the template strand known as the non-coding strand?
The template strand runs antiparallel to the mRNA and its sequence of DNA is counter to what the mRNA will code. Therefore the coding strand would be the DNA strand complementary to the template strand as its sequence is almost identical to the mRNA except for the substitution of Uracil.
100
Where does translation occur?
Ribosomes
100
What is the difference in the genome of a heart cell vs a skin cell?
None, each cell has the same genome but are expressed differently
100
Trisomy 21 is a phenomena caused by the incorrect separation of chromosomes during replication. What is this called?
Non-disjunction (NDJ)
200
The 3 main structural differences between DNA and RNA
Sugar (ribose vs deoxyribose), uracil in RNA and single stranded RNA
200
RNA polymerase reads DNA in which direction?
3' to 5' direction (RNA synthesizes in the 5' to 3')
200
What is the start codon? What is its amino acid?
AUG, Methionine
200
How do transcription factors relate to the differentiation of cell types?
The absence or presence of certain tfs determine which phenotypic genes are expressed and thereby the function of the cell.
200
Errors in DNA replication, DNA repair, exposure to radiation and reactive chemicals (mutagens) can lead to....?
Random Mutations
300
DNA is replicated in which direction and why?
5' to 3' because nucleotides can only be added on the 3' OH
300
Spliceosomes (snRNPs) are enzymes which do what?
Splice/cut introns away from pre-mRNA and are responsible for alternative splicing.
300
What are the three steps of translation and what happens in each?
Initiation - binding of mRNA to ribosome
Elongation - covalent bonding of amino acids by rRNA to form polypeptide chain
Termination - reading of the STOP codon which initiates ejection of polypeptide chain to be used for protein formation
300
Within prokaryotes, if lactose is abundant but glucose is scarce what will happen to the lac operon?
the lac operon will be activated and the gene which codes for lactase will be expressed to breakdown lactose
300
Explain the prokaryotic mechanisms of horizontal gene transfer
- transformation
- transduction
- conjugation
- Transformation is the uptake of "naked" genetic information
- Transduction is through the forcible insertion via a vector
- Conjugation is cell to cell transfer of genetic information via a pilus structure (the tubes)
400
Describe the function of the following in replication:
- Helicase, Topoisomerase, Ligase, Polymerase
Helicase - unzips
Topoisomerase - releases tension
Ligase - patches up Okazaki fragments
Polymerase - Adds DNA nucleotides to the original strand
400
What are the benefits/purposes of noncoding introns?
Buffers for mutations, allow alternative splicing which can create greater efficiency of expression and allow more varied products to be created from simpler instructions
400
In what site of the ribosome does rRNA covalently attach amino acids chains to each other to form a polypeptide?
The P site
400
What do operons produce?
a single mRNA molecule which codes for specific genes
400
Which kid is not biologically related to the mother?
Child 3 is not from the mother
500
What type of organisms contain plasmids and where are they contained?
Both prokaryotic and eukaryotic organisms can house plasmids however in prokaryotes plasmids are in the cytosol and in eukaryotes they are housed in the nucleus.
500
What modifications are necessary for a pre-mRNA to reach mature mRNA status?
Addition of a GTP cap and Poly-A tail, excision of introns and retention of exons via enzyme mediated reactions.
500
What are the 4 types of RNA and what do they do?
mRNA - protein code
tRNA - amino acid carrier
rRNA - ribosomal structure which binds amino acids
sRNA - gene regulator which binds to mRNA post transcription
500
What is the purpose of the TATA box?
It is the site by which transcription begins on the template DNA strand where the start of the gene begins (aka the promoter site upstream of the gene)
500
Explain how PCR amplifies DNA
Technique involves several steps
- DNA is denatured to separate strands
- Primers are added and temp is lowered at optimal binding temp
- DNA is replicated via polymerases
- Process is repeated until ample amount of DNA is obtained