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#‼️BIOCHEMISTRY - PLE TOPNOTCH 2020 > GENETICS > Flashcards

Flashcards in GENETICS Deck (53)
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31

What are the 3 stop codons that terminate translation

(UAG, UAA, UGA)

32

Start or initiating codon in eukaryotes

(AUG) methionine

33

Start or initiating codon in prokaryotes

formylmethionine

34

• The poisonous mushroom Amanita phalloides (“death cap”) contains the peptide toxin α-amanitin which inbitits the RNA polymerase II

• Presents with gastrointestinal symptoms, acute liver failurea, and may be fatal

AMANITA MUSHROOM POISONING

35

o Inactivates the eukaryotic elongation factor EF-2, preventing translocation

Exotoxin of Corynebacterium diphtheriae

36

• Binds to the β subunit of bacterial DNAdependent RNA polymerase

Rifampicin

37

Binds to the DNA template and interferes with the movement of RNA polymerase during transcription

Dactinomycin

38

Bind to the 30S subunit and interferes with initiation

aminoglycosides and streptomycin

39

Prevents binding of aminoacyl-tRNA to the A site

Tetracycline

40

Inhibits peptidyltransferase prokaryotic

Chloramphenicol

41

Inhibits eukaryotic peptidyltransferase

Cycloheximide

42

purine to purine or pyrimidine to pyrimidine

Transition

43

purine to pyrimidine or pyrimidine to purine

Transversion

44

• New codon codes for same amino acid

• No effect on protein

Silent Mutation

45

• New codon codes for different amino acid (conservative if new amino acid is similar in chemical structure)

• Variable effects on protein

Missense Mutation

46

• New codon is a stop codon

• Shorter than normal, usually non-functional protein

Nonsense Mutation

47

• Deletion or addition of bases that should not be multiples of three

• Shorter than normal, usually non-functional protein

FRAME SHIFT MUTATION

48

• Loss of large areas of chromosomes during unequal crossover in meiosis

• Loss of function

• Protein shorter than normal or entirely missing

LARGE SEGMENT DELETION

49

• Splice site is lost

• Variable effects ranging from addition or deletion of a few amino acids to deletion of an entire exon

• Examples: Tay-Sachs, Gaucher, β-thalassemia

SPLICE DONOR OR ACCEPTOR

50

• Expansions in coding regions cause protein product to be longer than normal and unstable

• Diseases often show anticipation in pedigree

TRIPLE REPEAT EXPANSION

51

CAG repeats

Huntington Disease

52

CGG repeats

Fragile X Syndrome

53

CTG repeats

Myotonic Dystrophy