Chapter 11, Nucleic Acid Structure and DNA Flashcards

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1
Q

Genetic material needs to…..(4)

A
  • contain information to build and run an entire organism
  • be copied accurately
  • be transmitted, passed from parent to offspring (cell to cell)
  • Account for the known variation within and between species
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2
Q

_________________ determined what Genetic Material was

A

a series of experiments

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3
Q

Most scientists believed…

A

genetic material was proteins since they were known to be much more variable than nucleic acids

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4
Q

There are _____ amino acids and ____ nucleotides

A

20, 4

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5
Q

________ set stage for showing what genetic material would be in …

A

Griffith, 1928

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6
Q

Griffith worked with….

A

two strains of bacteria Streptococcus pneumoniae

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7
Q

The ______ strain was _______ and jilled mice with a pneumonia infection

A

S (smooth) virulent

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8
Q

The ____ strain was _____ and the mouses immune system would kill it

A

R (rough) not virulent

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9
Q

Griffith performed ____ experiments

A

four

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10
Q

Griffith’s first experiment…

A
  • injected mice with S strain and saw that mice died
  • after death, living S bacteria were found in the blood
  • this established virulence of S strain

control: injected living type S bacteria into mouse

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11
Q

Griffith’s second experiment…

A
  • injected mice with R strain and saw that mice did not die
  • dead bacteria were found in the blood
  • established non-virulence of R strain

Control: injected living type R bacteria into mouse

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12
Q

Griffith’s third experiment…

A
  • heat killed the virulent S strain and injected the dead S strain
  • mice did not die
  • bacteria was killed and found inside blood

Control: Injected heat-killed type S bacteria into mouse

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13
Q

Griffith’s fourth experiment…

A
  • he then mixed the live R strain (harmless) with the heat killed S strain (harmless) and injected it into mouse
  • Mice did, living S strain was recovered

Control: Injected living R and heat killed S into mouse

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14
Q

Whatever agent that had transformed R into S…

A

must be the genetic material

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15
Q

This transforming material is called…

A

transforming factor

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16
Q

__________ did more detailed experiment in _____

A

Oswald Avery et al., 1944

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17
Q

Published results in

A

1944

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18
Q

They performed the same part of the fourth experiment which is…

A

took live R and mixed with heat killed S

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19
Q

Difference in experiment is they…

A

first treated it with enzymes to destroy some class (or another) of organic molecules

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20
Q

Treated heat killed S strain with _______ to destroy proteins

A

proteases

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21
Q

When they injected heat killed S with proteases to destroy proteins and then added these to live R proteins …

A
  • the mice still died
  • if genes in the heat killed S strain were proteins, they should have been destroyed and not able to transform the live R into the S strain
  • therefore GENES (PROTEINS) were NOT genetic material
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22
Q

Treated heat killed S with _____ to destroy nucleic acids

A

nucleases

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23
Q

When they treated heat-killed S with nucleases to destroy nucleic acids and added this to live R strain

A
  • the mice lived
  • genes must consist of nucleic acids since when they are destroyed, so it ability to transform the R strain to the lethal S strain
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24
Q

This was…

A

first demonstration that genes were nucleic acids

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25
Q

Doubts about experiment were..

A
  • doubts about purity of samples
  • or weather small amounts of contaminating molecules could have been altering the results
26
Q

So people were..

A

still skeptical

27
Q

Second demonstration on nature of genes was done by __________ in ______

A

Hershey and Chase (1952)

28
Q

Hershey and Chase used…

A

radioactive isotopes in viruses

29
Q

Of all organic molecules only _____ have _____

A

proteins have sulfur

30
Q

So if you grow viruses in radioactive (35)S…

A

only proteins will be “labeled”

31
Q

Used viruses because

A

viruses were trusted, studied

32
Q

Only _____ _____ have _________

A

nucleic acids, phosphorus

33
Q

Viruses grown in radioactive (32)P…

A

will only label nucleic Acids

34
Q

So, they grew…

A

viruses in two separate mixtures, P32 (nucleic acids) and S35 (proteins)

35
Q

Viruses are also called

A

bacteriophages

36
Q

Viruses…

A

inject their genes into bacteria and genes use bacterial cell to produce more viruses

37
Q

Whatever genes are…

A

should be found inside the bacterial cells after infection

38
Q

After growing viruses for several generations in S35(proteins)…

A

they infected the bacteria with the proteins

39
Q

The result of this was..

A

the bacteria did not contain the 35S (protein)

40
Q

Therefore this shows that…

A

genes must not consist of proteins since radioactive proteins were NOT INSIDE THE BACTERIA (genes not injected into bacteria, nor found in next gen of viruses)

41
Q

After growing viruses for several generations in P32(nucleic acids)

A

they infected bacteria with these viruses

42
Q

The result of this was…

A

the bacteria contained P32 (nucleic acids)

43
Q

Therefore this shows that…

A

genes must consist of NUCLEIC ACIDS because these ENDED UP INSIDE CELL (injected into bacteria and found in next generation of viruses)

44
Q

This experiment with Hershey and Chase was…

A

second definitive demonstration that genes were made of nucleic acids (DNA)

45
Q

______ and ________ in _____ determined structure of DNA

A

Watson and Crick (1953)

46
Q

Watson and Crick used information from

A

Rosalind Franklin, Erwin Chargaff, Maurice Wilkins

47
Q

They described that DNA has…

A

double helix with sugar-phosphate backbone and nitrogenous bases projecting inward in complementary pairs

48
Q

Monomer subunits of nucleic acids are

A

nucleotides

49
Q

Nucleotides consist of

A
  • pentose sugar
  • nitrogenous bases
  • phosphate group
50
Q

Only different between RNA and DNA is

A

ON CARBON #2

RNA has hydroxyl (OH) on C#2
DNA has just H on C#2

51
Q

DNA Backbone composed of

A

Sugars and phosphates

52
Q

Sugars and phosphates connected with

A

phosphodiester linkage

53
Q

The top 5 carbon and bottom 3 carbon

A

become connecting points for the chain

54
Q

Four bases in DNA and RNA

A

DNA - ACG and T
RNA - ACG and U

55
Q

Difference between thymine and uracil

A

Thymine has methyl (CH3) group, uracil just has H

56
Q

Purines are

A

Adenine and Guanine, DOUBLE RING

57
Q

Pyrimidines are

A

Cytosine, Uracil, Thymine, SINGLE RING

58
Q

Pairing relationships

A

A and T(U) - 2 H bonds
C with G - 3 H bonds

59
Q

The two DNA strands run in…

A

opposite directions, ANTIPARALLEL STRUCTURE

60
Q

Watson and Crick published official paper in

A

April 25, 1953

61
Q

Paper published in magazine

A

nature

62
Q

They proposed in paper that the structure of DNA shows…

A

a copying mechanism, structure and function linked