Path 3

Question 1

what are the 3 types of point mutations?

Answer 1

• substitution
• insertion
• deletion

Question 2

substitutions can be either?

Answer 2

transitions or transversions

Question 3

what are transitions?

Answer 3

interchanges of purines (A,G) or of pyrimidines (C,T)
- involve bases of similar shape

Question 4

what are transversions?

Answer 4

interchanges of purine for pyrimidine bases
- involve exchange of one-ring and 2 ring structures

Question 5

what does frameshift mutation mean

Answer 5

all of the triplets are off by one due to an insertion or deletion

Question 6

what’s another name for a frameshift mutation

Answer 6

frame-shifting indels

Question 7

what is a non-frameshifting indel

Answer 7

if a multiple of 3 nucleotides are inserted or deleted, then the reading frame is preserved

Question 8

what is a silent or conservative missense point mutation

Answer 8

little or no change in function

Question 9

what is a nonconservative missense point mutation?

Answer 9

significant change in function

Question 10

what is a non-sense mutation?

Answer 10

if the nucleotide triplet being changed becomes a stop codon, then there will be premature ending of translation

Question 11

all mutations are bad T or F

Answer 11

false, not all mutations are bad

Question 12

provide an example where mutations can be a good thing

Answer 12

mutation in the sickle-cell trait where it protects people against malaria

Question 13

autosomal dominant mutations are

Answer 13

structural proteins

Question 14

autosomal recessive mutations are

Answer 14

enzyme deficient

Question 15

mendelian disorders are due to?

Answer 15

due to mutations in single genes that have large effects

Question 16

autosomal dominant disorders

Answer 16

• manifested in heterozygous or homozygous state
• usually have at least one parent with the disorder exception if it is a spontaneous mutation

Question 17

what does penetrance mean?

Answer 17

how likely the mutated gene is to be expressed

Question 18

what does expressivity mean?

Answer 18

how “much” the disorder-causing gene is expressed

Question 19

Marfan Syndrome

Answer 19

disorder of connective tissues, manifested principally by change skin, skeleton, eyes, and cardiovascular system
- autosomal dominant, chromosome 15
- loss of fibrilin-1

Question 20

what is the largest category of Mendelian disorders?

Answer 20

autosomal recessive disorders

Question 21

list some of the causes of lysosomal storage diseases

Answer 21

• range of lysosomal enzymes problems
• lack of the enzyme
• misfolding of the enzyme
• lack of a protein activator that binds to the substrate and improves the ability of the enzyme to act on it

Question 22

what is a “primary storage” problem?

Answer 22

deficiency or malfunction of one of the enzymes -> incomplete catabolism -> insoluble intermediates that accumulate in the lysosomes

Question 23

what is a “secondary storage” problem?

Answer 23

toxic effects from defective autophagy

Question 24

gaucher disease

Answer 24

autosomal recessive
- defect in the gene for glucocerebrosidase which cleaves the glucose residues from ceramid found in membranes

Question 25

Gaucher disease Type I

Answer 25

involves organs outside the CNS - 99% of cases
- mostly within the spleen and bone
- enlargement of the spleen and bone
- weakened bones - frequent fractures

Question 26

Gaucher disease Type II

Answer 26

involves the CNS as well as other organs
○Hepatosplenomegaly and rapid neurological deterioration, with death in early childhood
○ CNS macrophage activation -> production of toxic signals by macrophages -> neuronal death

Question 27

all sex-linked disorder are…

Answer 27

X-linked