Chapter 4 bio
If a DNA double helix contains 28% T nucleotides, then what is the percentage of A nucleotides?
28%
By convention, nucleotide sequences are always written from the _____.
5 end to the 3 end
When nucleotides polymerize to form a nucleic acid
A Covalent Bond forms between the sugar of one nucleotide and the phosphate of a second.
Which of the following are purine nitrogenous bases?
Guanine and Adenine
The wrapping of DNA around proteins is an example of what level of DNA structure?
Tertiary
What is the significance of the 2' hydroxyl on ribose for RNA function compared to DNA, which lacks the hydroxyl group at the 2' position?
The 2' OH increases the reactivity of RNA.
What is a major feature of the RNA world hypothesis?
The first life-forms probably had RNA as their unit of genetic information.
The condensation reaction that forms nucleic acid polymers occurs between a _____ group on one nucleotide and a _____ group on a second nucleotide.
phosphate; hydroxyl
An RNA molecule that can catalyze chemical reactions is called a
ribozyme
Bartel's research group showed that an RNA replicase ribozyme could be created by
starting with random components and allowing selection to result in molecules that were better and better at replicating
RNA is much more diverse in size, shape, and reactivity than DNA?
true
Compare proteins to nucleic acids. Which of the following is true?
both have primary and secondary structure
Which of the following features was required by the first life-form, according to the chemical evolution theory? The first living molecule had t
both provide a template that could be copied and catalyze polymerization reactions
Scientists recognized that to obtain evidence that life arose spontaneously at some point in history, they needed to find a molecule that was capable of carrying (in other words storing) information and was capable of self-replication. One piece of evidence critical in proposing the RNA world hypothesis was the discovery of _____ by Sidney Altman and Thomas Cech.
ribozymes
What are the components of a nucleotide?
sugar, phosphate group, nitrogenous base
Nucleotides are joined by a _____ to form the DNA and RNA polymers that function in the cell.
sugar-phosphate linkage
Which of the following statements describes the secondary structure of DNA? DNA's secondary structure consists of
two antiparallel DNA strands twisted into a double helix
If one strand of a DNA molecule has the sequence of bases 5'ATTGCA'3, the other complementary strand would have the sequence?
3'TAACGT'5
Which of the following descriptions best fits the class of molecules known as nucleotides?
A nitrogenous base, A phosphate group, A sugar.
How do the structures of RNA and DNA differ?
Adenine pairs with thymine in DNA, while adenine pairs with uracil in RNA.
The work of Bartel's group on the ribozyme RNA replicase supports which conclusion?
An RNA world could produce molecules that could self-replicate.
Which of the following makes it possible for DNA to serve as a template both for DNA synthesis and for RNA synthesis?
Complementary base pairing enables DNA to serve as a template.
Which of the following are purine nitrogenous bases? Guanine and Adenine The difference between the sugar in DNA and the sugar in RNA is that the sugar in DNA?
Contains one less oxygen atom
Which of the following are pyrimidine nitrogenous bases?
Cytosine and Uracil
Which of the following includes all the pyrimidine's found in RNA and DNA?
Cytosine, Uracil, Thymien
The sequence of nitrogenous bases in an RNA and DNA strand is always written in the 5′ ? 3′ direction because
DNA and RNA are synthesized in this direction in cells
In which of the following ways does DNA differ from RNA? SHOW HINT
DNA contains deoxyribose sugar, whereas RNA contains ribose.
Which of the following best describes DNA's secondary structure?
Double antiparallel helical strands
DNA is capable of self-replication?
False
One of the primary functions of RNA molecules is to?
Function in the Synthesis of Proteins.
Which statement regarding complementary base pairing is correct?
In DNA, the purine base adenine (A) pairs with the pyrimidine base thymine (T).
What is true of the hairpin structure found in some RNA molecules? SHOW HINT
It is an example of RNA secondary structure.
Which statement correctly describes one aspect of the precise bonding between components of a nucleotide?
Nitrogen in the nitrogenous base bonds to the 1′ carbon of sugar.
In a nucleic acid polymer, the bonds that help to hold double-stranded regions together occur between what parts of the nucleotide monomers?
Nitrogenous bases
Which of the following can both catalyze chemical reactions and carry information to copy itself?
RNA
Experiments in Dr. David Bartel's laboratory have tried to generate ribozymes that can perform which of the following reactions?
RNA replication and ribonucleotide monomer production
Researchers hypothesize that the first self-replicating molecule may have been ____. This is known as the ______world hypothesis.
RNA; RNA
For nucleotides to form in the prebiotic soup, which sugar in the following list would have had to be present in abundant quantities?
Ribose
Question 8:Which DNA sequence, written in the 5' to 3' orientation, is complementary to 5' CATGGACTA 3'?
TAGTCCATG
Which of the following components of a nucleotide is uniquely found in DNA?
Thymine (T)
All of the following components of a nucleotide are found in both RNA and DNA with one exception. Identify the exception.
Thymine (T) !
When nucleotides polymerize to form a nucleic acid _____.
a covalent bond forms between the sugar of one nucleotide and the phosphate of a second
The secondary structure of DNA is due primarily to
hydrogen bonding between complementary bases
In a DNA double helix, what kind of chemical bonds form between the complementary nitrogenous bases?
hydrogen bonds
The potential energy needed to drive polymerization of DNA or RNA is primarily stored in the bonds between __________ of an activated nucleotide.
phosphate groups
