Topic 8 Flashcards
Key words
What is a mutation?
A change in the base sequence of an organisms DNA
What are mutagenetic agents?
Something that increases the rate of DNA mutations
What are genetic disorder?
An inherited disorder that is caused by an abnormal gene or chromosome
What are hereditary mutations?
A mutation that is inherited from your parents
What are frameshift mutations?
A mutation that changed the number if bases in the DNA code, causing a shift in base triplets. So the triplet code is read in a different way
What are acquired mutations?
Mutations that you develop during your lifetime
What is a tumour- suppressor gene?
A gene that slows the rate of cell division by producing proteins that stop cells dividing or cause them to self destruct
What is a protooncogene?
A gene that produces proteins that make cells divide
What is an oncogene?
A mutated protooncogene that stimulates cells to divide uncontrollably
What is cancer?
A tumour that invades surrounding tissues
What is the difference between a benign and malignant tumour?
A benign tumour is non-cancerous. A malignant tumour is a cancerous tumour.
What is hypermethylation?
When there is too much methylation. The tumour suppressor gene is not transcribed, proteins aren’t produced, cell division increases and becomes uncontrollable so tumours form.
What is hypomethylation?
When there is too little methylation. It causes protooncogenes to behave like oncogenes which increases the rate of production of proteins. this increases rate of cell division, it becomes uncontrollable so tumours form
What is gene therapy?
Possible treatment options for genetic disorders and some cancers. It involves altering detective genes inside cells.
What are totipotent stem cells?
Stem cells that can develop into any type of body cell
What is a pluripotent stem cell?
Can develop into any type of cell, except those that make up the placenta
What is a unipotent stem cell?
Can only differentiate into one type of cell
What is a multipotent stem cell?
Can only develop into a few types of cells
What are cardiomyocytes?
Heart muscle cells
What are transcription factors?
A protein molecule that controls the transcription of a gene
What are promoters?
A region of a DNA sequence that tells the enzyme RNA polymerase where to start producing mRNA
What are activators?
A transcription factor that increases the rate of transcription
What are repressors?
A transcription factor that inhibits or decreases the rate of transcription
What is RNAi?
RNA interference
Mechanism by which siRNA or miRNA affects translation
What is siRNA?
Small interfering RNA (Double stranded)
Interferes with transcription and translation of genes
What is miRNA?
Small, single stranded
Interfere with translation of genes
What is methylation?
The attatchment of a methyl group to something like DNA
What is acetylation?
Attatchment of an acetyl group to something like histones
What is an oestrogen-oestrogen receptor complex?
When oestrogen binds to a transcription factor called an oestrogen receptor as they are complementary to each other, and they form a complex
What are antiparallel base pairs?
Base pairs that read the same in opposite directions
What is cDNA?
Complementary DNA
What are restriction endonucleases?
An enzyme that recognises specific recognition sequences and cuts DNA at these places
What are palidromic sequences?
A sequence of DNA bases that consist of antiparallel base pairs
What is reverse transcriptase?
An enzyme that makes a DNA copy of RNA
What are sticky ends?
A small tail of unpaired DNA bases at the end of a DNA fragment
What are olinucleotides?
Short sections of DNA that are around 20 nucleotides long, that can be joined together to make longer DNA fragments
What is In-vivo cloning?
Making gene copies in living organisms. The organism grows and divides, then replicates DNA, creating multiple copies of a gene
What is In-vitro cloning?
Making gene copies outside of living organisms. Using polymerase chain reactions.
What is ligation?
The process of joining together sticky ends of DNA fragments using an enzyme called ligase.
What is recombinant DNA?
DNA formed by joining together DNA from different organisms
What are marker genes?
A gene that can be inserted into transformed cells to identify them
What are primers?
Short pieces of single stranded DNA that is complementary to the bases at the start of the DNA fragment you want to copy
What is a microarray?
A glass slide with microscopic spots of different DNA probes attactched to it in rows
What is genetic fingerprinting?
A DNA gel that shows the number of items repetative, non-coding base sequences are repeated at different loci in an individual
What is a lac repressor?
A transcription factor
What is DNA polymerase?
An enzyme that joins together the nucleotides on a new strand of DNA in DNA replication
What are complex-regulatory genes?
They control the expression of one or more genes. They determine when genes that code for particular proteins should be switched on or off.
What is a polymerase chain reaction (PCR)?
A reaction used to make DNA fragments outside of living organisms. It is involved in IN-vitro cloning
What is a promoter region?
Provides binding areas for RNA polymerase, signalling where transcription of the gene should start
What is genetic engineering?
Transformation of plants and animals using recombinant gene technology
What is genetic fingerprinting?
The number if times a sequence is repeated at different places in the genome can be compared between individuals
What are VNTR’s?
Variable number tandem repeats. Which are base sequences that don’t code for proteins, but instead repeat next to each other over and over again.
What is a DNA ladder?
A mixture of DNA fragments of known length which allows us to work out length of other bands on the gel.
What is a proteome?
All of the proteins that are made by an organism
