MCB 2610 FINAL/EXAM 4
3 major macromolecules in cell - correct answer ✔- DNA
- RNA
- proteins and enzymes
deoxyribonucleic acid (DNA) - correct answer ✔storage molecule for genetic
instructions to carry out metabolism and reproduction
ribonucleic acid (RNA) - correct answer ✔expresses the information in DNA
proteins and enzymes - correct answer ✔build cellular structures and do
cellular work
genome - correct answer ✔all DNA present in a cell or virus
genotype - correct answer ✔specific set of genes an organism possesses
phenotype - correct answer ✔collection of observable characteristics
Griffith experiment - correct answer ✔- one of the earliest experiments that
pointed out that DNA could contribute hereditary info in bacteria was the work
of Griffith in the 1920s with smooth (S) and rough (R) strains of S.
pneumoniae
-his work hinted at the idea of something that could transform a non-
pathogenic R strain into a pathogenic S strain of microbes when the two were
mixed together
,Griffith's Transformation Experiments - correct answer ✔* Live S stain ->
mouse dead
* Live R stain -> mouse unharmed
* Heat-killed S strain -> mouse unharmed
* Heat killed S strain + Live R strain -> mouse unharmed
Avery, MacLeod and McCarty experiment - correct answer ✔- performed in
the early 1940s
- attempted to determine if it was DNA, RNA or protein that was responsible
for the "transformation" effect observed in Griffith's experiments
- used mixtures obtained from S strains but digested away one component at
a time
- only the mixture with DNA left over could still transform R cells into S cells,
indicating DNA was the molecule responsible for transformation
Hershey-Chase experiment - correct answer ✔- 1952
- some biologists thought that contaminating bits of protein or RNA could still
be present in the DNA-only mixture of the Avery/MacLeod/McCarty
experiments
- Hershey and Chase used radioactive labeling of either proteins or DNA in
bacteriophages
- they let the labeled phages infect bacterial cells, then determined where the
tag ended up for each setup
- only the labeled phage DNA went into the bacterial cells, further proving that
DNA (not protein) was the hereditary molecule in these experiments
Flow of Genetic Infromation - correct answer ✔- central dogma
- from one generation to the next : DNA stores genetic information;
information is duplicated by replication and is passed on to next generation
,central dogma - correct answer ✔- the pathway from DNA to RNA to protein
is gene expression
- DNA -> RNA -> protein
- conserved in all cellular forms of life
- DNA divided into genes
-- transcription yields a RNA copy of specific genes
-- translation uses information in mRNA to synthesize a polypeptide ; also
involves activities of transfer RNA (tRNA) and ribosomal RNA (rRNA)
Structure of DNA - correct answer ✔- the work of Rosalind Franklin, James
Watson and Francis Crick in the early 1950s elucidated the now well known
double-stranded double helix structure of DNA
- each nucleotide building block of DNA consists of
* a 5-carbon sugar, 2-deoxyribose
* a phosphate group attached to the 5' carbon of the sugar
*a nitrogenous base attached to the 1' carbon of the sugar
Composition of Nucleic Acids - correct answer ✔- look at chapter 7 ppt slide
17
DNA Structure - correct answer ✔* polymer of nucleotides
- bases are adenine, guanine, cytosine & thymine
- sugar is deoxyribose
- phosphate is esterified to sugar carbon
* sugar phosphate backbone
- covalent bonds between the 3'-hydroxyl of one sugar and a 5'-hydroxyl of an
adjacent sugar
, Structure of DNA . - correct answer ✔- one strand of DNA is complementary
to the other strand
- A pairs with T; G pairs with C by hydrogen bonding
- phosphodiester covalent bonds from the sugar/phosphate backbone of each
strand
Packaging of DNA across 3 domains - correct answer ✔* overall structure of
DNA is the same across all 3 domains, the way it is packaged is NOT
- Bacteria : a single circular chromosome
- Archaea : a single circular chromosome packaged around histone proteins
- Eukarya : multiple linear chromosomes packaged around histone proteins
Structure of DNA .. - correct answer ✔- the wrapping of dsDNA around
histones helps compact the very large chromosome structures of eukaryotic
cells
- the stacked genome copies may help give this bacterium its strong radiation-
damage resistance trait
DNA Replication - correct answer ✔- complex process involving numerous
proteins which help ensure accuracy
- the 2 strands separate, each serving as a template for the synthesis of a
complementary strand
- synthesis is semi-conservative; each daughter cell obtains one old and one
new strand
Replication Machinery - correct answer ✔- Bacteria: consists of at least 30
proteins, one origin of replication
- Archaea: more similarities to eukaryotic replication machinery, many
replication forks in Eukaryotes
3 major macromolecules in cell - correct answer ✔- DNA
- RNA
- proteins and enzymes
deoxyribonucleic acid (DNA) - correct answer ✔storage molecule for genetic
instructions to carry out metabolism and reproduction
ribonucleic acid (RNA) - correct answer ✔expresses the information in DNA
proteins and enzymes - correct answer ✔build cellular structures and do
cellular work
genome - correct answer ✔all DNA present in a cell or virus
genotype - correct answer ✔specific set of genes an organism possesses
phenotype - correct answer ✔collection of observable characteristics
Griffith experiment - correct answer ✔- one of the earliest experiments that
pointed out that DNA could contribute hereditary info in bacteria was the work
of Griffith in the 1920s with smooth (S) and rough (R) strains of S.
pneumoniae
-his work hinted at the idea of something that could transform a non-
pathogenic R strain into a pathogenic S strain of microbes when the two were
mixed together
,Griffith's Transformation Experiments - correct answer ✔* Live S stain ->
mouse dead
* Live R stain -> mouse unharmed
* Heat-killed S strain -> mouse unharmed
* Heat killed S strain + Live R strain -> mouse unharmed
Avery, MacLeod and McCarty experiment - correct answer ✔- performed in
the early 1940s
- attempted to determine if it was DNA, RNA or protein that was responsible
for the "transformation" effect observed in Griffith's experiments
- used mixtures obtained from S strains but digested away one component at
a time
- only the mixture with DNA left over could still transform R cells into S cells,
indicating DNA was the molecule responsible for transformation
Hershey-Chase experiment - correct answer ✔- 1952
- some biologists thought that contaminating bits of protein or RNA could still
be present in the DNA-only mixture of the Avery/MacLeod/McCarty
experiments
- Hershey and Chase used radioactive labeling of either proteins or DNA in
bacteriophages
- they let the labeled phages infect bacterial cells, then determined where the
tag ended up for each setup
- only the labeled phage DNA went into the bacterial cells, further proving that
DNA (not protein) was the hereditary molecule in these experiments
Flow of Genetic Infromation - correct answer ✔- central dogma
- from one generation to the next : DNA stores genetic information;
information is duplicated by replication and is passed on to next generation
,central dogma - correct answer ✔- the pathway from DNA to RNA to protein
is gene expression
- DNA -> RNA -> protein
- conserved in all cellular forms of life
- DNA divided into genes
-- transcription yields a RNA copy of specific genes
-- translation uses information in mRNA to synthesize a polypeptide ; also
involves activities of transfer RNA (tRNA) and ribosomal RNA (rRNA)
Structure of DNA - correct answer ✔- the work of Rosalind Franklin, James
Watson and Francis Crick in the early 1950s elucidated the now well known
double-stranded double helix structure of DNA
- each nucleotide building block of DNA consists of
* a 5-carbon sugar, 2-deoxyribose
* a phosphate group attached to the 5' carbon of the sugar
*a nitrogenous base attached to the 1' carbon of the sugar
Composition of Nucleic Acids - correct answer ✔- look at chapter 7 ppt slide
17
DNA Structure - correct answer ✔* polymer of nucleotides
- bases are adenine, guanine, cytosine & thymine
- sugar is deoxyribose
- phosphate is esterified to sugar carbon
* sugar phosphate backbone
- covalent bonds between the 3'-hydroxyl of one sugar and a 5'-hydroxyl of an
adjacent sugar
, Structure of DNA . - correct answer ✔- one strand of DNA is complementary
to the other strand
- A pairs with T; G pairs with C by hydrogen bonding
- phosphodiester covalent bonds from the sugar/phosphate backbone of each
strand
Packaging of DNA across 3 domains - correct answer ✔* overall structure of
DNA is the same across all 3 domains, the way it is packaged is NOT
- Bacteria : a single circular chromosome
- Archaea : a single circular chromosome packaged around histone proteins
- Eukarya : multiple linear chromosomes packaged around histone proteins
Structure of DNA .. - correct answer ✔- the wrapping of dsDNA around
histones helps compact the very large chromosome structures of eukaryotic
cells
- the stacked genome copies may help give this bacterium its strong radiation-
damage resistance trait
DNA Replication - correct answer ✔- complex process involving numerous
proteins which help ensure accuracy
- the 2 strands separate, each serving as a template for the synthesis of a
complementary strand
- synthesis is semi-conservative; each daughter cell obtains one old and one
new strand
Replication Machinery - correct answer ✔- Bacteria: consists of at least 30
proteins, one origin of replication
- Archaea: more similarities to eukaryotic replication machinery, many
replication forks in Eukaryotes
