Tumours Flashcards
Definition of a malignant tumour.
Cancerous, divides rapidly and spreads via the blood system.
Definition of a benign tumour.
Not cancerous, slow growth and doesn’t spread.
What are tumour suppressor genes?
They repress the cell cycle (stop the division of cells) and promote the self destruction of cells
What happens if there’s a mutation in the tumour suppressor gene?
The cells will be able to divide uncontrollably, and form a tumour
What happens if there’s a mutation in the proto-oncogene?
The cells will divide uncontrollably, forming a tumour.
What are Porto-oncogenes?
They promote the cell cycle (encouraging the division of cells)
How are tumour cells different to normal cells?
They’re larger, darker and contain multiple nuclei.
How do tumour suppressor genes work?
They produce proteins which stop/destruct cells.
What are the different mutations which can occur to the bases in DNA?
Substitution. Deletion. Duplication. Translocation. Addition. Inversion.
What do mutagenic agents do? How do they work? What’s an example of one?
They increase the rate of mutations.
They can act as bases, alter bases and change the structure of DNA.
Chemicals in cigarettes and radiation.
Definition of methylation.
Adding a methyl group to a molecule.
What are the two types of methylation? Which has to occur to the tumour suppressor gene to cause a tumour to grow? Which has to occur to the proto-oncogene to cause a tumour to grow?
Hypermethylation: too much methylation - causes a tumour to growth if happens on the tumour suppressor gene.
Hypomethylatio: too little methylation - causes tumour growth if happens on the proto-oncogene.
Definition of a risk factor.
Something which increases the chance of getting a disease.
What does incidence refer to?
The number of people diagnosed with a disease in a certain population time.
What does prevalence refer to?
The number of people who have a particular condition - regardless of diagnosis.
What is screening used for?
To see if someone has a specific allele that could possibly increase the chance of them getting a cancer.
Within cancer treatment, what do drugs do?
They reduce the effect that mutated genes have.
What does chemotherapy do? What is the downside to chemo?
It stops the fast division of cells, but I can harm healthy cells that divide quickly, such as hair and the cells on the inside of the mouth.
What does radio therapy do?
It emits high energy radiation to shrink rumours and kill their cells by ruining the DNA.
What is gene therapy?
The use of modified viruses to deliver replacement genes, they alter DNA to connect mutations.
What is siRNA?
Small interfering RNA.
What is miRNA?
Micro interfering RNA.
What is siRNA’s function?
It’s a double stranded type of RNA that cuts mRNA into smaller fragments.
What is miRNA’s function?
It’s made from pre-miRNA, and it cuts mRNA into smaller fragments.
What are transcription activators?
They activate transcription, by helping RNA polymerase bind.
What are transcription repressors?
They decrease transcription, by slowing/preventing RNA polymerase from binding.
What is transcription?
The making of mRNA, using helicase to unzip the 2 stands in DNA to use them as a template to attach free floating nucleotides with RNA polymerase.
What is frame shift?
The removal/addition of (a) base/s, leading to a shift of the other bases.
What are stem cells?
Unspecialised cells that can develop into different cells.
Definition of totipotent.
Stem cells which can develop into any cell.
Definition of pluripotent.
Stem cells which can develop into all cells except placenta cells.
Definition of unipotent.
Stem cells which can only develop into one specific cell.
Definition of differentiation.
The developing into another cell.
