Who worked in the early 1900s and was interested in bacteria that caused pneumonia?
Fredrick Griffith
What organism did Fredrick Griffith work with?
rats
Who worked with 2 strands: S (smooth) strand and R (rough) strand?
Fredrick Griffith
Describe Fredrick Griffith's first experiment.
?: What strand was pneumonia
Ex: injected rats with S strand and R strand
Results: S strand died, R strand lived
C: S strand was pneumonia
Describe Fredrick Griffith's second experiment.
?: What caused pneumonia (toxin?)
Ex: heat treated S and injected it into rats to kill the bacteria and if it still killed them then it was a toxin
Results: lived
C: A toxin doesn't cause pneumonia
Describe Fredrick Griffith's third experiment.
?: What happens
Ex: mixed the dead S with the living R
Results: they all died, strand looked like the S but was living
C: something was passed between the bacteria
Why is the concept of transformation important for understanding heredity?
just the fact that genetic info is passed along from one cell to the next
Describe Avery's experiment.
?: What is passed between bacteria
Ex: combined a strand of bacteria w/ carbs, lipids, proteins, RNA, or DNA
Results: All rats died except w/ DNA
C: DNA is passed in bacteria
a virus that attacks bacteria
bacteriophage
What are the 2 parts of bacteriophages?
protein shell and DNA
Describe Hershey and Chase's experiment.
?: What was passed between bacteria and viruses
Ex: tagged one virus with sulfur and one with phosphorus then infected bacteria with the virus
Results: sulfur was on the outside and phosphorus was on the inside
C: DNA is passed between viruses and bacteri
Who discovered what?
a. Fredrick Griffith
b. Avery
c. Hershey/Chase
a. something was passed between bacteria
b. DNA is passed between bacteria
c. DNA is passed between bacteria and viruses
What makes up the backbone of the DNA?
phosphate and sugar
What makes up the "rings.steps" of the DNA?
nitrogenous bases
What are the nitrogenous bases for DNA?
Adenine, Thymine, Cytosine, Guanine
Which bases are always paired together for DNA?
A and T
C and G
What are the purines of DNA? Pyrimidines?
Purines- A and G
Pyrimidines- C and T
What does Chargaff's rule state?
The amount of A will always be equal to T, and the amount of C will always be equal to the amount of C.
Which scientist worked with X-ray diffraction?
Franklin
Who discovered that DNA had an x shape, and had 2 strands?
Franklin
Which scientist(s) discovered that the DNA has a double helix meaning that its 2 strands run together?
Watson/Crick
lines that don't run in the same direction
antiparallel
Why is important for the DNA to have antiparallel lines? Why is this important for the arrangement of the nitrogenous base?
So it can wrap around itself and it means whatever is on one side there is going to be the complementing base on the other
What bonds in DNA help form the double strands?
weak hydrogen bond
Why is a hydrogen bond more useful in DNA than a stronger bond?
in case you want to open it up to copy it or make proteins
What are the 3 main parts of DNA?
Antiparallel lines, Hydrogen Bonds, and base pairing
Why does a cell undergo replication?
so it can pass the correct info
What are the 3 main roles of enzymes in DNA replication?
1. unwind the DNA
2. unzip the DNA
3. copy the DNA
What are the 2 main roles of DNA polymerase?
1. add new bases to the new DNA strand
2. checks for errors
found at the end of the DNA strands
telomeres
an enzyme that copies telomeres
telomerase
Compare telomeres and telomerase in an adult cell vs a cancer cell.
Adults have short telomeres and a low amount of telomerase while cancer patients have the opposite.
What is the main difference between DNA in a prokaryotic cell vs a eukaryotic cell?
P: DNA in middle
E: DNA in nucleus
What is the difference between prokaryotic reproduction and eukaryotic reproduction?
P: one starting point
E: multiple starting points
What is the main purpose of RNA?
to be the copy of the DNA taken outside of he nucleus to make a protein
DNA is the "_______ _______"
RNA is the "_______ _______
master code
cheap copy
What are 3 differences between DNA and RNA?
DNA:
thymine
double stranded
deoxyribose
RNA:
uracil
single stranded
ribose
What are the 3 main actions/parts of RNA?
mRNA: copies DNA
rRNA: aids in production of proteins
tRNA: brings proper AA for protein production
Where is the mRNA taken? Why?
to the cytoplasm and then the ribosomes because thats where proteins are made
What is the main purpose of transcription?
RNA being copied from the DNA strand
What is the difference between transcription and replication?
In transcription, only the area of DNA that is needed is unwound
the enzyme that is used to generate or create the mRNA strand
RNA polymerase
What are the 2 roles of RNA polymerase?
1. add bases to mRNA chain
2. unzips DNA for transcription
What is the main role of a promoter?
to tell the mRNA where to start to get the strand that you need for a certain protein
the part of the mRNA strand that are cut out prior to being sent to the ribosome
intron
the parts that are kept and fused together to create the mRNA strand
exons
T/F:
The cell can't repair its own DNA.
true
How does the right tRNA molecule know to bring the right AA?
matches up the anticodon with the codon
What are the main roles of mRNA, tRNA, and rRNA in translation?
mRNA: cheap copy of DNA coding for AA chain
tRNA: brings the AA to the ribosomes
rRNA: being used to attach the AA to one another in the growing