Molecular Flashcards
To learn USMLE molecular biochemistry
What is Lupus?
Systemic Lupus Erythematosus (SLE) is an autoimmune disease that causes fever, joint pain, and red lesions on the skin and affects the multiple organs.
What is the etiology of lupus?
Unknown but most likely a combo of genetics and environment.
What is the difference between histone methylation and DNA methylation?
Transcription activation or repression in both cases…thats pretty much it
What makes drug induced lupus different from classic lupus?
Drug induced lupus has anti-histone antibodies as opposed to anti-dsDNA antibodies. It is milder and manifests more typically as joint pain.
Commonly, but not exclusively, binding is to H1 histone linker protein.
Explain the mechanism for a histone deacetylation inhibitor drug? Would transcription be activated or deactivated in most cases?
TRANSCRIPTION WOULD OCCUR.
deacetylation is the taking away of acetyl groups that “loosen” the chromatin. Therefore, the chromatin condenses and transcription does not occer. a deacetylation inhibitor would stop the deacetylation from occurring, thus, transcribing the genes that would normally be silenced.
What is systolic heart failure?
a problem with how the heart pumps blood to the rest of the body effectively or how it improperly fills with blood. Heart failure can be caused by heart conditions or chronic diseases.
CARDIO: what is ejection fraction?
Ejection fraction (EF) is a measurement, expressed as a percentage, of how much blood the left ventricle pumps out with each contraction. An ejection fraction of 60 percent means that 60 percent of the total amount of blood in the left ventricle is pushed out with each heartbeat.
what is leptin?
a hormone predominantly made by adipose cells and enterocytes in the small intestine that helps to regulate energy balance by inhibiting hunger, which in turn diminishes fat storage in adipocytes. Leptin acts on cell receptors in the arcuate nucleus of the hypothalamus.
When does cross-over and genetic recombination occur?
Meiosis 1
Does cross-over/recombination occur during mitosis?
NO. because homologues do not normally pair at mitosis
What is the most common mutation leading to Cystic Fibrosis?
delta-f508 cftr.
present in approximately 70 percent of people with CF, is F508del. This mutation is caused by the deletion of three base pairs of the CFTR gene leading to the loss of an amino acid called phenylalanine, abbreviated F, in the CFTR protein.
what is the role of cyclins in the cell cycle?
Cyclins bind to CDK which phosphorylate necessary proteins (i.e. E2F proteins in G1/S checkpoint) to trigger growth
E2F then releases Rb which triggers cell growth.
what is a colposcopy?
A procedure to closely examine the cervix, vagina, and vulva.
What is the major function of p53?
It prevents cell growth! by stimulating transcription of p21 which in turn binds to CDKs. if CDKs are occupied, then cyclins can’t bind to them, so no growth.
*p53 is only activated when phosphorylated WHEN THERE IS DNA DAMAGE.
What do E2F proteins do?
bind to Rb protein in order to keep cell cycle arrested.
