Exam 1 CHP 1-2 Flashcards
(39 cards)
What are the two chemical components of chromosomes
DNA and Protein
Why did researchers originally think that protein was the genetic material
They had a lot of functions, complex, more of them
Distinguish between S and R strains; summarize the experiment in which Griffith discovered there had to be hereditary information
The r strain was safe, but the S strain was not. Living R bacteria had been transformed into S strain by an unknown heritable substance (S factor)
How did Avery, Mcarthy, and Macleod determine the transforming S-factor was likely DNA and not protein? What enzymes were used and why?
The N/P ratio of the S-strain was closer to DNA and not protein. They used RNase, Protease, and DNase to destroy those molecules
Three different bonds S-W, describe them
Covalent (shared) Ionic (donate receive electrons) Hydrogen (partial charges)
How did Hershey and Chase “label” viral DNA and viral protein so that they could be distinguished?
Used radioactive isotopes of sulfur and Phosphorous to tag protein and DNA
Explain why Hershey and Chase chose each radioactive tag considering the chemical composition of DNA and protein
Only protein contains sulfur and only DNA contains phosphorus
How many different DNA sequences of eight bases can you make?
How many different Amino Acid sequences of eight amino acids can you
make?
4^8, 20^8
How did Hershey and Chase establish that only DNA entered the cell? What conclusions did they draw
Radioactive DNA cells entered the host cells but the protein did not. DNA must hold the genetic information
List the three components of a nucleotide
Phosphate group, 5 pentose carbon sugar, nitrogenous group
What was Rosalind Franklin’s role in the discovery of the double helix
she had conducted critical experiments that allowed Watson and Crick to get the double helix
What are the structures of Pyrimidines and Purines? What are they? Why do they bond
Pyrimidines (Cytosine and Thymine) are 6-membered rings and Purines (Adenine and Guanine) are 6-membered rings fused to 5-membered. Because they are opposites
what is meant by 5’ and 3’
one end is attached to a 5’ carbon other is 3’
What is the semiconservative model of replication
Two Strands of the parental DNA molecule separate and each serves as a template
Draw and Explain the three banding patterns after 1 and 2 rounds of bacterial replication
See drawing
What is a hypothesis
Testable explanation for a set of observations
In the mouse coloration experiment what factors were held constant
Camoflouged mouse in normally resident area
Which enzyme adds DNA nucleotides, and why? What is the direction of the new strand
DNA Polymerase, because of its structure. 5’-3’
If the population is 6x larger than the initial population how many generations passed
2.585
How many times larger is a population 10^8 than 10^3
100,000
A DNA molecule has 180 base pairs and 20% are adenine. What percentage is cytosine, and how many nucleotides
.30 108 Cytosine
Draw and label the 3 types of RNAs and describe them in the central dogma
mRNA-dispersed throughout the whole thing, because it varies in size since they are long strands. least abundant. (DNA is copied into mRNA)
tRNA- the bottom, the smallest (brings correct amino acid to ribosomes)
rRNA-most abundant. 2 rings, has two sizes. Structure of a ribosome (synthesize protein)
What is RNA splicing? what are kept and whats removed
mRNA can be spliced in different ways to produce multiple versions. allows a single gene to code for many proteins. Introns are removed, exons are kept.
What is gene expression
information encoded in DNA directs the synthesis of proteins
