Flashcards in Chapter 10 Questions Deck (15):
Relate how Griffith's experiments showed that a hereditary factor was involved in transformation.
Griffith's experiments showed that a hereditary factor was involved in transformation because the experiment showed that hereditary material moves from one bacterial cell to another during transformation. Griffith was studying S. pneumoniae. He discovered the S strain had a covering and the R strain did not. The S strain was harmful while the R strain was not. He injected R strain and S strain into mice and only the mice with the S strain died. Heat-killed S cells did not kill the mouse but heat-killed s cells with r cells did kill the mice. This showed that the S cells transformed the R cells and made them harmful.
Summarize how Avery's experiments led to the conclusion that DNA is responsible for transformation in bacteria.
Avery's experiments led to the conclusion that DNA is responsible for transformation in bacteria because they proved that cells missing RNA and proteins could transform R cells, but if it was missing DNA it could not.
Describe how Hershey and Chase's led the conclusion that DNA, not protein is the hereditary molecule in viruses.
The Hershey and Chase experiment produced evidence that DNA, not protein, is the hereditary material in viruses because they found that all of the viral DNA and little of the protein had entered the E. coli cells. They used radioactive isotopes to label the protein and DNA in the bacteriophages. They used radioactive sulfur to label protein and radioactive phosphorus to label DNA. They removed the bacteriophages from the cells in a blender and then they used a centrifuge to separate the bacteriophage from the E. coli cell. This showed that all of the viral DNA and little of the protein had entered the E. coli cell. They concluded that DNA is the hereditary material in viruses.
Describe the contributions of Wilkins and Franklin in helping Watson and Crick discover DNA's double helix structure.
Wilkins and Franklin had produced photo 51 which was a very accurate picture of the DNA double helix structure.
What are the 3 parts of a nucleotide?
a phosphate group, a five-carbon sugar, and a nitrogenous base
Relate the role of base-pairing rules to the structure of DNA.
Adenine's complementary base is Thymine
Cytosine's is guanine. These A-T's and C-G's form a double strand of DNA, the template strand and its complement.
This is why it's double stranded. The weak hydrogen bonds between the pairs creates the helical shape of DNA.
Summarize the process of DNA replication.
Helices separate the DNA strands. The Y-shaped region that forms is called a replication fork. Enzymes called DNA polymerases add complementary nucleotides. Covalent bonds form between adjacent nucleotides. Hydrogen bonds from between the complementary bases on the original and new strands. DNA polymerases finish replicating the DNA and fall off. This type of replication is known as semi-conservative replication.
What are the enzymes and what are their roles in DNA replication?
The enzymes in DNA replication are helices and DNA polymerase. Helices separate the DNA strands. DNA polymerase add complementary nucleotides to each of the original strands.
What is complementary base pairing and how does it "guide" DNA replication?
Complementary base pairing is when the nucleotide bases in one strand of DNA or RNA are paired with those of another strand. It helps guide DNA replication because one strand can serve as a template during division.
Compare Eukaryotic and Prokaryotic DNA replication.
Eukaryotic replication has several origins while prokaryotic only has one.
Describe how errors are corrected during DNA replication.
DNA polymerase proofreads, checks for errors, and corrects them.
Outline the process of Protein synthesis (start from DNA and end with the production of polypeptide chain)
The first step in protein synthesis is the transcription of mRNA from a DNA gene in the nucleus. At some other prior time, the various other types of RNA have been synthesized using the appropriate DNA. The RNAs migrate from the nucleus into the cytoplasm. RNA polymerase bonds to a promoter and initiates transcription. RNA polymerase add complementary RNA nucleotides to one of the DNA strands. This creates an mRNA stand. The 3 nucleotide sequences called codons encode a specific amino acids for a polypeptide chain. mRNA and tRNA bind. The ends of tRNA contain the anticodon to that on the mRNA. The amino acids form a chain and are connected by polypeptide bonds. The complex falls apart and a protein is formed.
Compare the structure of RNA with DNA.
RNA contains ribose not deoxyribose, it has uracil not thymine, it is singe-stranded not double, and it is shorter than DNA.
Compare the role of mRNA, rRNA, and tRNA in translation.
The mRNA carries the blueprint for the protein. The tRNA carries the amino acids fro the protein and matches anticodons on the mRNA. The rRNA is part of the ribosome assembling the protein.