Basis of Human Disease Flashcards
What is a single nucleotide polymorphism (SNP)? And what can it be used for??
A single nucleotide substitution/ difference between 2 sets of DNA. Can be used to identify disease in a patient. If the same difference is in all patients with same disease, can prove it i related. Also used to predict patients response to a drug and to track inheritance of DNA.
What is autosomal dominance?
carriers also have the symptoms. if you get the abnormal gene from only one parent, you can get the disease. Often, one of the parents may also have the disease.
What is X linked?
Used to describe a characteristic or condition in which an alteration in one gene on the X chromosome causes the condition in males but not usually when females have one copy of the altered gene.
What is sickle cell anaemia?
Sickle cell disease is a group of disorders that affects hemoglobin. People with this disorder have atypical hemoglobin molecules called hemoglobin S, which can distort red blood cells into a sickle, or crescent, shape. Effects the Hb which is a tetramer, the 6th amino acid changes from Glutamine to Valenine so changes shape of protein to a rod. Carriers have a slight sickle making them immune to malaria.
What is Duchene Muscular Dystrophy?
Duchenne muscular dystrophy (DMD) is a genetic disorder characterized by progressive muscle degeneration and weakness. It is X linked. Due to muscle wastage as the protein Dystrophin connects muscle to the ECM maintaining integrity.
What is huntingtons disease?
brain has neuronal loss in basal ganglia, expand of repeat CAG so increase size of polyglutamine tract that is toxic to neurones.
What is a pulmonary emphysema?
Chambers in lung collapse, enlarged alveoli as loss of elastin in the walls.
Reduction of anti proteases so proteases destroy walls. Disrupts the equilibrium between proteases and anti proteases.
Neutrophils release elastase and protease.
Toxins detected by macrophages so they release metalloproteases that destroy alveolar.
Results in decrease in SA, air trapped in exhalation and no elastic recoil.
What is a virus?
DNA or RNA encased in a protein coat (capsid).
It encodes proteins that replicate, package up the DNA and deliver to host cells. Modify host to enhance replication, then exit via lyses or budding off.
What is used to generate the genome in each class of virion?
1 = dsDNA to mRNA 2 = ssDNA to dsDNA to mRNA 3 = dsRNA to mRNA 4 = ssRNA to mRNA 5 = RNA polymerase makes -ve RNA to mRNA 6 = reverse transcriptase RNA to dsDNA to mRNA
How does the HPV virus cause cancer?
accidental integration of the virus into the basal epithelial cells during proliferation , forming tumours. The genome of HPV contains oncogenes E6 and E7. These turn up DNA replication resulting in unregulated cell proliferation
How do virus’ cause cancer ?
Incorporate human protoncogenes into their genome when they integrate. It modifies the genes, switching them on, altering them to gain a function
How are protooncogenes and viral oncogenes named?
if protooncogene = has the prefix c
if viral = prefix v
eg c -sarc turns to v-sarc which is then active and can cause cancer
