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BCHM 270 Module 1 Test With
Correct Answers
Nucleotide - ANSWER - basic structural unit for DNA
- each one contains a nitrogenous base, a 5-carbon sugar, and at least 1 phosphate group difference between DNA and RNA - ANSWER - the sugar group is deoxyribose (missing the OH group on the 2nd carbon) or ribose (this makes ribose more polar than DNA so it won't form a double strand)
- RNA is single stranded
- RNA used uracil and DNA uses thymine nitrogenous bases of nucleotides - ANSWER - adenine
- cytosine
- thymine (only in DNA)
- uricil (only in RNA) purines are the energy current of the cell - ANSWER - ATP
- GTP Energy storage in ATP - ANSWER - the 2 outer phosphate binds of ATP are "high energy"
endergonic reaction - ANSWER - requires energy
- ATP releases energy for that reaction exergonic reaction - ANSWER - energy released
- ATP can take that energy to convert from ADP to ATP (stores the energy in the bonds) DNA - ANSWER - 2 antiparallel stands of nucleotides that interlock through hydrogen bonding Purpose of DNA - ANSWER - provides a blueprint for RNA and proteins
- store genetic information Central Dogma of Molecular Biology - ANSWER DNA -> RNA -> Protein Different Types of RNA - ANSWER tRNA -transfer RNA
- carries amino acids to the ribosomes rRNA
- ribosomal RNA
- makes up the ribosomes miRNA and mRNA
- micro and messenger RNA
- are translated into amino acid sequences to make peptides and proteins 3 components of the central dogma - ANSWER - replication, transcription, and translation
of RNA ribosome - ANSWER - the small unit is responsible for binding to the mRNA
- the large subunits has sites where the peptide is built sites on the large subunit of ribosome - ANSWER - acceptor site (where tRNA first attach to the ribosome)
- peptides site (where the newly arrived amino acid is removed from the tRNA and added to the peptide by a peptide bond)
- Exit site (where the tRNA is ejected and where the polypeptide is guided and released) 3 steps of translation - ANSWER - initiation (AUG)
- elongation (adds amino acids to the COOH end of the peptide)
- termination (elongation is continued until the stop codon is reached) standard genetic code - ANSWER - all the codons
- start codon is Met (AUG)
- stop codons are UAA, UAG, UGA DNA mutations can be detrimental or not detrimental - ANSWER - mutations that cause proteins to be affected are detrimental
- mutations like polymorphisms are not polymorphisms - ANSWER - rare DNA mutations that do not cause disease
- ex. blood types allele - ANSWER Different forms of a gene produced by a polymorphism
classifying Mutations - ANSWER - structural changes (can be small or large)
- functional changes small-scale structural mutations - ANSWER - silent
- missense
- nonsense
- frameshift silent mutation - ANSWER A mutation that changes a single nucleotide, but does not change the amino acid created. missense mutation - ANSWER when a point mutation changes 1 amino acid of a protein nonsense mutations - ANSWER - a point mutation results in an early stop codon
- stops the protein from being made frameshift mutation - ANSWER - results from an inserted or deleted nucleotide which shifts the codon sequences large scale structural mutations - ANSWER - large scale rearrangements of DNA (we don't learn in this course) Functional changes in mutations - ANSWER - mutations can be classified by how they affect the function of the protein
- gain of function mutation, loss of function mutation, dominant negative mutation
sticky ends - ANSWER - restriction endonuclease cut the DNA staggered that that the ends have sequences that are complementary to each other
- the ends can form hydrogen bonds
blunt ends - ANSWER - restriction endonuclease cut in the middle of a sequence
- no hydrogen bonds can form
- gel electrophoresis - ANSWER - DNA, RNA, molecules are put into gel and are separated by charge because the smallest ones move quickest
- the gel is stained to see the fragments
- DNA cloning - ANSWER - method to isolate a DNA sequence and introduce it into a cell to amplify that DNA sequence
- the DNA sequence is cut out using restriction endonucleases
- the DNA fragment is joined to a DNA cloning vector (which helps bring foreign DNA into a cell, ex. plasmid)
- the vector and the DNA sequence have complimentary stick ends to attach
- this goes into the cell and then divides, adding that DNA sequence into the cells
- DNA Probes - ANSWER - DNA probes are dyed and have a complimentary sequence to the DNA of interest
- the probe is added into the cell and then it binds with the DNA of interest and helps target it
DNA Probes: Allele Specific Oligonucleotides (ASO) - ANSWER - Oligonucleotides probes can be designed to bind to only 1 version of an allele (polymorphism or mutation) to determine is the sample contains them
- if the sample has the mutations, the ASO probe is dyed and it attaches and we can see
- Blotting - ANSWER - fragments of DNA, RNA, or proteins are separated using gel electrophoresis and then transferred to a nylon or nitrocellulose membrane -BLOCKING- the membrane is washed with a prehybridization solution that includes a blocking agent that reduces the nonspecific binding of the probe during hybridization
- HYBRIDIZATION - the membrane is washed with dyed/labelled DNA probes that only target the DNA/RNA. They will bind to the DNA sequence in questions
- we are then able to see if the DNA is present SNOW DROP
- DNA microarrays - ANSWER - can be designed to determine the location of the mutation in a gene, or to look for multiple polymorphisms
- compares large numbers of samples simultaneously
- the amount of flurosences is a direct measure od how much specific DNA is in a sample
- CRISPR Cas9 - ANSWER - can be used for genetic modification
- adaptive immunity
- researcher can design RNA sequences that they want cleaved in the cell, and CRISPR-Cas9 will modify the gene
CRISPR Adaptive immunity - ANSWER - used in bacteria where they use CRISPR to identify previously encountered viral DNA and attack it with restriction endonuclease before it can hijack the cell
CRISPR - ANSWER - "the brain"
- viral DNA fragments are saved so the cell can recognize future viral invasions and sent the Cas9 to cleave the DNA
Cas 9 - ANSWER - the enzyme that cuts the DNA in question being guided by Cas
RNA BIOTECHNOLOGY - ANSWER
- Northern Blot - ANSWER - used to show and detect specific RNA sequences
- gel electrophoresis
- moved fragments on to the membranous paper
- Quantitative PCR - ANSWER - measures relative gene expression in samples
- mRNA is reverse transcribed to produce cDNA (complimentary DNA) -qPCR goes in a thermocycler with a reaction with fluorescent probes that produce a signal with increasing amount of DNA present
- cDNA microarray - ANSWER - mRNA will reverse transcribe into cDNA with reverse transcriptase
- the cDNA from 2 different tissues (example sick vs healthy) can be flourescnelty labelled and mixed up and then exposed to a gene microarray chip
- the chip has thousands of DNA oligonucleotide spots, each of which corresponds to to a specific DNA sequence from the DNA of interest
- the amount of fluorescence that binds to each spot correlated to the each
- ELISA - ANSWER - 2 types of ELISA direct sandwich
- uses a 96-well assay to look for protein expression
direct ELISA - ANSWER - the wells are coated with the antigen of interest
- used to check blood samples for antibodies, or to check for immunity after vaccines
Sandwich ELISA - ANSWER - the capture antibody is bound to the 96-well plate
- the unknown sample with the unknown amount of antigen (protein) is added to the well
- the plate is washed and the unbound sample is washed away
- the detecting antibody that binds to the protein is then added to the plate, and then washed away 1 hour later
- the secondary antibody is added which binds to the detecting antibody (wash plate again)
- add the colour substrate which causes the secondary antibody to change colour
- the reaction is stopped using sulphuric acid, and the plate is read
Western Blots and ELISA Assays - ANSWER - western blots and ELISA assays can confirm each other
