Molecular Biology Flashcards
What does DNA stand for?
Deoxyribonucleic acid
What is a gene?
An inheritable unit that is a sequence of DNA
What is a genome?
The entire genetic makeup of an orgamism
DNA can contain 4 different kinds of bases. What are these 4 bases?
Adenosine, Thymine, Guanine, Cytosine
Explain basic DNA structure in terms of sugars, phosphates and bases
DNA has a sugar phosphate backbone. The bases attach to the sugar and to a complimentary base which then attaches to the other sugar phosphate backbone.
Explain the ‘central dogma’ of molecular biology
DNA makes DNA. DNA makes RNA. RNA makes protein
BRIEFLY explain the statement ‘the information for making a new strand of DNA comes from an old strand of DNA’
The DNA splits to form 2 new DNA molecules which are identical due to the complimentary bases.
What is transcription?
DNA is transcribed to create RNA. RNA synthesis
What is translation?
RNA is translated into proteins. Protein synthesis
In one short sentence explain what an Intron is
A segment of DNA or RNA that does not code for proteins and interrupts the sequence of genes
In one short sentence explain what an Exon is
A segment of DNA or RNA that codes for proteins or peptide sequences
What is a codon?
A sequence of 3 nucleotides which together form a unit of genetic code in DNA or RNA molecule
What is meant by the term ‘Genetic Code’?
A set of rules in which the living cells translate information in the genetic material into proteins
What are two differences between RNA Polymerases and DNA polymerases?
RNA does not require a primer
DNA uses thymine not uracil
BRIEFLY explain what a restriction enzyme is
a restriction enzyme cuts DNA at a specific site, depending on the enzyme
BRIEFLY explain what a ligase enzyme is
Ligase enzyme is the molecular glue that holds together nucleotides in DNA
Explain how PCR could be used for sex determination
DNA samples can be taken, amplified and analysed to determine the SRY protein (the protein which determines sex)
State 3 additional applications PCR could be used for
Genetic engineering
Producing human insulin from bacteria
Detecting viruses
What are the steps of a PCR reaction? Describe what happens at each step
Denaturation
- The DNA is split into 2 ssDNA
Annealing
- Primer is annealed to the strands
Extension
- The DNA is rebuilt from where the primers attached
Are there any infectious, disease-causing agents that can not be detected using a PCR-type reaction? If so, name one such agent or disease.
Prions are a protein based infectious agent which do not have nucleic acid. Therefore they are not detected with a PCR test.
Describe an application of electrophoresis
Analyse and purify proteins, DNA and RNA
When electrophoresed over a given period of time, will a small DNA molecule usually migrate a shorter distance or a further/longer distance through an agarose gel, compared to a large DNA molecule?
A smaller DNA molecule will travel a longer distance than a larger molecule
True or False. Electrophoresis can separate molecules based on both size and charge?
True
What types of molecules can be separated using electrophoresis?
DNA, RNA and proteins
A certain type of PAGE can be used to separate denatured proteins. What are denatured proteins?
Denatured proteins are proteins that have broken the weak bonds (hydrogen bonds) and have lost their native state.
