Chapter 15-17 Biology Flashcards
The primer that is binding to a DNA sequence is made of ___.
RNA
DNA polymerase can/can’t start without a 3’ OH already there.
can’t
What part of DNA gives it a charge?
Phosphate
What is one molecule that is found in protein but NOT DNA?
Sulfur (disulfide bond in tertiary structure)
In the experiment with radioactive viruses, where was the radioactive DNA found? Where was the radioactive protein?
Radioactive DNA: inside cells, in pellet
—> confirms that genes are made of DNA
Radioactive protein: inside solution
—> confirms capsids are made of protein
Which of the following best describes the composition of DNA monomers?
a) All of the monomers contain ribose connected to one of four nitrogenous bases
b) All of the monomers contain a phosphate group connected to a nitrogenous base
c) All of the monomers contain a phosphate group and a nitrogenous base connected to a deoxyribose.
C
5 prime end is characterized by a ___ and the 3 prime is characterized by an ___ group.
phosphate, OH
In DNA, what type of bond is between the bases?
Van der Waals
DNA replication is semiconservative because replicated DNA molecules are composed of ___.
a) 2 strands of old DNA
b) 2 strands of new DNA
c) 1 strand of old DNA and 1 strand of new DNA
d) 1 strand of new DNA
C
What did the Meselson-Stahl Experiment prove?
DNA replication is semi-conservative
Meselson-Stahl Experiment results proving semi-conservative replication.
After two generations, 1/2 of DNA was low density and the other 1/2 was intermediate density.
DNA polymerase catalyzes DNA ___.
synthesis
Deoxyribonucleotides are only added to the __’ end of a growing DNA chain. Synthesis always from ___ to ___ prime
3’, 5 to 3
DNA synthesis requires energy, making it ___.
endergonic
Why is ATP a good source of energy?
Three phosphates that are all negatively charged want to repel and release a lot of energy.
How many origins of replication do bacterial chromosomes have?
1
How many origins of replication do eukaryotes have?
Many
What happens when origins of replication meet?
They make one big bubble.
What breaks the hydrogen bonds between DNA strands (think of secondary structure)?
DNA helicase
What attaches to separated strands to prevent them from closing?
Single-strand DNA-binding proteins (SSBPs)
What cuts and rejoins DNA to relieve tension caused by unwinding DNA?
Topoisomerase
Where is the origin of replication?
Replication fork
____ synthesizes RNA primer.
Primase
DNA polymerase synthesizes __ to ___
5’, 3’
DNA polymerase can only add on to existing 3’ __ groups, which is why we need RNA primer in ___ replication.
OH, DNA
What prevents the shortening of telomeres during replication?
Telomerase, has its own RNA template
True or False: Telomeres contain genes
False
Telomerase is primarily found in ___, ___cells, and ___ cells.
gametes, stem, cancer
List 3 outcomes of adding telomeres to cell cultures
- Allows them to continue to divide
- Cancer usually has active telomerase, passing checkpoints unregulated
- Allows for unlimited cell division
What proofreads in DNA synthesis?
DNA polymerase
When does mismatch repair occur?
When mismatched bases are corrected after DNA synthesis is complete.
Nucleotide excision repair
- Proteins detect irregularities in DNA structure
- An enzyme NICKS DNA on both sides of damage
When do the following happen?
Proofreading –>
Mismatch repair –>
Telomere repair –>
Nucleotide excision repair –>
synthesis, synthesis, extending telomeres, interphase
What is the One Gene, One Enzyme hypothesis? (Beadle and Tatum)
Each gene contains information to make an enzyme. IT IS SUPPORTED
What is the OGOE hypothesis also referred to as?
One Gene, One polypeptide
DNA –> ___ –> Protein
mRNA
What do the following RNAs stand for?
mRNA
tRNA
rRNA
mtRNA
messenger
transfer (seen in translation)
ribosomal (seen in translation)
mitochondrial
mRNA carries DNA info to ___, which takes place in the ___ during ___.
ribosomes, cytoplasm, transcription
RNA processing takes place in the ___.
nucleus
Translation takes place in the ___.
cytoplasm
RNA polymerase synthesizes ___ and can work without a ___.
RNA, primer