Molecular basis of inheritance Flashcards
What is the difference between a deoxyribonucleotide and a ribonucleotide?
The presence of an -OH at the 2’ carbon
What are the purines?
Guanine and adenine
What is a purine?
Nucleotide with 9 atoms in its ring such as guanine and adenine (the ones with ‘nine’)
What are the pyrimidines?
Thymine and cytosine
What is a pyrimidine?
Nucleotide with 6 atoms in its ring such as thymine and cytosine (the ones without ‘nine’)
What is dATP?
Deoxyadenosine triphosphate (sugar has only one -OH group)
How do nucleotides join together to form a polynucleotide?
2 phosphate groups are lost from each nucleotides - phosphodiester bonds form between nucleotides.
SINES
Short interspersed elements
LINES
Long interspersed elements
What does ncRNA do?
Non-coding RNA can control exon splicing and decoding of mRNA
What does snRNA do?
Small nuclear RNA forms complexes with proteins to form small nuclear ribonucleoprotein particles (snRNPs) which splice pre-mRNAs
What are snRNPs?
Small nuclear ribonuclearprotein particles, splice pre-mRNAs.
2 Examples of X-linked recessive disorders that reveal X-inactivation
Anhydrotic ectodermal dysplasia, random patches of tissues w/o sweat glands
Red/green colour blindness, mosaic retinas
What is anhydrotic ectodermal dysplasia
Random patches of tissues w/o sweat glands
What is the name of the condition where there are random patches of tissues w/o sweat glands?
Anhydrotic ectodermal dysplasia
What does the Xist gene do?
Dosage compensation - inactivates one of the X chromosomes by supercondensation to prevent transcription
What is miRNA
MicroRNA, regulates expression of specific genes.
Transcription of miRNA gives hairpin precursor; exported to cytoplasm where nuclease cuts off loop, two single strands formed. They pair w/ coding mRNA causing translational repression
What are some examples of miRNA disorders?
miR-96 = hereditary progressive hearing loss miR-184 = EDICT, degenerative eye disorder
What is miR-96
Hereditary progressive hearing loss
What is miR-184
EDICT, degenerative eye disorder
What are some examples of mitochondrial disorders?
LHON = Leber's hereditary optic neuropathy MELAS = mitochondrial encephalomyopathy lactic acidosis and stroke-like episodes
What is MELAS
Mitochondrial encephalomyopathy lactic acidosis and stroke-like episodes
What is LHON
Leber’s hereditary optic neuropathy
