chapter 9 - dna structure & replication

Question 1

friedrich miescher

Answer 1

• swiss physician and biochemist
• isolated nuclei from white blood cells in pus
• found acid substance with N and P, later named nucleic acid

Question 2

archibald garrod

Answer 2

• english physician
• linked inheritance of inborn errors of metabolism with the lack of particular enzymes

Question 3

what did frederick griffith work with?

Answer 3

streptococcus pneumoniae bacteria

Question 4

2 types of streptococcus pneumoniae bacteria

Answer 4

type s - smooth - enclosed in a polysaccharide capsule
type r - rough - no capsule

Question 5

griffith’s experiments showed that a molecule in a _____ type of bacteria can ______ nonkilling (______) bacteria into killers (______).

Answer 5

lethal; transform; nonvirulent; virulent

Question 6

does type R kill the mouse?

Answer 6

no

Question 7

does type S kill the mouse?

Answer 7

yes

Question 8

does heat-killed type S kill the mouse?

Answer 8

no

Question 9

does type R and heat killed type S together kill the mouse?

Answer 9

yes

Question 10

what can be found from the mouse that died from type R and heat killed type S?

Answer 10

live type S bacteria

Question 11

avery, macleod, mccarty

Answer 11

• american physicians
• treated lysed S bacteria with protease and DNase
• only DNase prevented transformation

Question 12

avery et al discovered that adding _____ led to mouse living and adding ____ led to mouse dying

Answer 12

DNase; protease

Question 13

avery et al discovered that ______ transforms bacteria and _____ does not

Answer 13

DNA; protein

Question 14

alfred hershey and martha chase

Answer 14

• american microbiologists
• used E coli bacteria infected with a virus that had a protein “head” or coat surrounding dna
• grew a batch of virus in a medium with 35S and 32P
• blender experiments showed that the virus transfers DNA, not protein, into a bacterial cell

Question 15

phoebus levene

Answer 15

• russian-american biochemist
• identified 5-carbon sugars ribose in 1909 and deoxyribose in 1929
• revealed chemical distinction between RNA & DNA (ribose vs deoxyribose)
• discovered that the 3 parts of nucleotide are found in equal proportions (sugar, phosphate, base)
• a nucleic acid building block must contain one o each component