Week 1 Flashcards
What Physical phenomenon is responsible for Hydrophobic and Hydrophlic interactions in the tertiary structure of proteins?
Van Der Waal’s forces
Which sugar component of DNA and RNA is rich in oxygen?
RNA
List the five Nitrogenous Bases:
Guanine
Cytosine
Adenine
Thymine
Uracil
The carbon ring in a nucleotide contains 4 or 5 Carbons?
4 Carbons
Three hydrogen bonds wil be found between which two Nitrogenous Bases?
Cytosine and Guanine
Defective duplicate genes found in eukaryotic cells are known as:
Pseudogenes
HOX genes clusters consist of normal genes, and what?
Pseudogenes
are expressed Pseudogene mRNA used for protein transcription?
No
What type of genes regulate axial development of the embryo?
HOX gene clusters
Are proteins encoded by rRNA?
no
What is unique about Introns found in LINEs?
(Long Interspersed Elements)
A coding sequence
What does LINEs stand for in DNA types?
Long Interspersed Elements
Alu elements (Named for the Alu 1 Restriction enzyme) are what type of DNA genes?
Short Interspersed Elements
SINEs
The template strand is the sense or antisense strand?
Sense strand
Polymerase works in which direction - 5’⇒3’ or 3’⇒5’?
5’⇒3’
Chromosomes are synthesised during G1 phase of the cell cycle.
True or False?
False
What is the diploid number for human somatic cells?
23
How many individual chromosomes are found in a cell during S phase?
96
At what phase of the cell cycle does the error checking of chromosomes formed during S phase occur?
G2
What are the molecules which toggle DNA replication and cell division activities?
Cyclins
What substrate must accumulate in the cytoplasm in order for mitosis to be triggered by cyclin-dependant kinase (Cdk)?
M-Cyclin
Which cyclin is the longest acting during the cell cycle?
G1/S-Cyclin
S-Cyclin
M-Cyclin
S-Cyclin
During which phase of the cell cycle does G1/S-Cyclin activity peak?
G1
M-Cyclin begins accumulating during which phase of the cell cycle?
G2
What process is required to trigger the degradation of M-Cyclin after mitosis?
Ubiquitination
What is the point on a chromosome where replication starts known as?
Ori
How does the process of sequential DNA replication made more time-efficient, given the extraordinary length of DNA molecules?
Multiple Ori
Allows parallel dna replication processes along the same chromosome
The Ori found along a chromosome consist of sequences rich in which nucleotide pairs?
AT or CG
AT
The Ori of chromosomes are rich in AT pairs, why?
Two H-bonds (as opposed to 3 in CG)
What is a synonym for Helicase?
MCM
What molecule must first bind with the Ori to initiate the assembly of the MCM (Helicase)?
ORC
Ori Recognition Complex
What component of the Helicase (MCM) is destroyed by S-Cdk?
Cdc6
Which Cyclin Dependant Kinase inactivates the ORC (Origin Recognition Complex)?
S-Cdk
S-Cdk causes the inactivation of ORC by destruction of Cdc6, why?
To prevent re-replication
<em>(DNA is replicated ONCE during the cell cycle)</em>
DNA is read in the 3’ ⇒ 5’ direction, hence DNA is synthesised in the:
5’ ⇒ 3’ direction
DNA molecules are antiparallel, meaning DNA is:
_____ in the 3’ ⇒ 5’ direction,
_____ in the 5’ ⇒ 3’ direction.
Read in the 3’ ⇒ 5’ direction,
Written in the 5’ ⇒ 3’ direction.
The Parental DNA strand is the Sense or Antisense strand?
Antisense
Exonucleases perform what function?
Error checking and correction
Continuation of the leading strand of DNA is done by which Polymerase?
DNA Polymerase Epsilon
Continuation of the lagging strand is carried out by which DNA Polymerase?
DNA Polymerase Gamma
What enzyme joins Okazaki fragments along the lagging strand together to form a complete strand (parallel to the parent?)
DNA Ligase
DNA Ligase is required to complete strands created by:
DNA Polymerase ε
or
DNA Polymerase δ
DNA Polymerase δ
The Hayflick Limit refers to what aspect of DNA replication?
Shortening of Telomeres, as DNA strands must be built in the 5’ ⇒ 3’ direction
Prior to AP Endonuclease and Phosphodiesterase removing a sugar molecule from DNA during repair, what enzyme must first act on the site of a nucleotide mismatch?
DNA Glycosylase
Xeroderma Pigmentosum is a disease caused by mutations in genes encoding what proteins?
Nucleotide Excision Repair enzymes
Are nucleotide sequences retained in non-homologous end joining (NHEJ) repair?
No
Bloom syndrome, a disease resulting in short stature, cancers and rash from sun exposure is a result of mutation in genes encoding what proteins?
DNA Helicase
Which feature of a DNA strand encodes proteins?
Exons
or
Introns?
Exons
What sequence precedes an exon along a DNA strand?
Promoter region
<em>(Includes the TATA box)</em>
What sequences upstream from the gene promoter site function to regulate DNA transcription to RNA?
Enhancers and Silencers
Behaviour of Enhancer and Silencer regions of DNA during transcription are regulated by:
What type of cell the DNA is located in
What is the purpose of Alternative Splicing in protein synthesis?
Allowing for multiple RNA/Proteins to be produced from the same set of exons.
What is the purpose of Polysomes?
allowing multiple proteins to be produced from the same mRNA simultaneously
Antisense RNA, miRNA and siRNA perform what functions?
Downregulation and suppresion of gene expression
Ribosomal subunits of 50S and 30S are associated with prokaryotes, or eukaryotes?
Prokaryotes
Ribosomal subunits of 40S and 60S are associated with prokaryotes or eukaryotes?
Eukaryotes
5’ Caps and Poly-A tails are features of Prokaryotic or Eukaryotic mRNA?
Eukaryotic mRNA
What is the function of Operons?
Regulating gene expression in prokaryotes
Bacteria which have mutated to resist antibiotic drugs will eventually become the majority of the population of that particular bacteria - is this horizontal or vertical resistance gene transfer?
Vertical
What are the three types of horizontal resistance gene transfer in bacteria?
Transformation
Conjugation
Transduction
Drug resistance gene transfer that is carried out through cell division is an example of vertical or horizontal gene transfer?
vertical
Resistance gene transfer that is achieved by transferring new DNA via a protein tube between adjacent bacteria is an example of:
- Conjugation*
- Transduction*
- Transformation?*
Conjugation
Resistance gene transfer that is achieved by introduction of new DNA by Bacteriophage (Virii) is an example of:
- Conjugation*
- Transduction*
- Transformation*?
Transduction
Resistance gene transfer that is achieved by absorption of new DNA from the external environment is an example of:
- Conjugation*
- Transduction*
- Transformation*?
Transformation
In transduction, the incorporation and proliferation of Phage DNA in to the chromosome of the host bacteria is known as:
Lysogenic Cycle
Lytic Cycle
Lysogenic
In transduction, phage DNA that utilises bacterial machinery to produce more copies of the virus (with the view to release from the cell) is known as:
The Lysogenic Cycle
The Lytic Cycle
Lytic cycle
A section of DNA incorporated in to the bacterial chromosome by a virus is known as a:
Prophage
During conjucation by bacteria, genetic material travelling through the sex pilus originates from the:
Bacterial Chromosome
or
a Plasmid?
Plasmid
Virii are Obligate Parasites - what does this mean?
They require the use of host machinery to reproduce
Genetic material, combined with Capsid Protein is known as a:
Nucleocapsid
A nucleocapsid consists of what two materials?
Capsid Protein
Genetic material (DNA or RNA)
What are the two morphological structures of viral genomes?
Linear
Circular
The two structures of viral genomes, Circular and Linear, are both further broken down in what two classifications?
Segmented
Non-Segmented
Which of the following virii are able to be used directly as mRNA for protein synthesis?
ssRNA (+)
ssRNA (-)
ssRNA (+)
What enzyme makes retroviruses unique?
DNA Reverse Transcriptase