30 terms

Intro to Cell Ch. 4

Identify three possible components of a DNA nucleotide.
deoxyribose, phosphate group, thymine
Sort the parts of a nucleic acid according to whether each occurs exclusively in DNA, exclusively in RNA, or in both types of nucleic acid. : thymine, deoxyribose, adenine, guanine, cytosine, phosphate, uracil, ribose
DNA: thymine, guanine
RNA: uracil, ribose
BOTH: adenine, guanine, cytosine, phosphate
Which statement accurately summarizes a difference between ribonucleotides and deoxyribonucleotides?
Ribonucleotides have a hydroxyl group bonded to their 2' carbon; deoxyribonucleotides have an H at the same location.
The condensation reaction that forms nucleic acid polymers occurs between a _____ group on one nucleotide and a _____ group on a second nucleotide.
phosphate, hydroxyl
In a nucleic acid polymer, the hydrogen bonds that help to hold regions of double-strandedness together occur between what parts of the nucleotide monomers?
nitrogenous bases
Some viruses consist only of a protein coat surrounding a nucleic acid core. If you wanted to radioactively label the nucleic acids separately from the protein, you would use _____.
radioactive phosphorus
Compare proteins to nucleic acids. Which of the following is true?
Both have primary and secondary structure.
DNA double helices are soluble in water but insoluble in alcohol. How do these physical properties reflect the chemical structure of the molecule?
The charged phosphate groups and sugars of DNA "like" to interact with polar water molecules.
Nucleic acids have a definite polarity, or directionality. Stated another way, one end of the molecule is different from the other end. How are these ends described?
One end has an unlinked 3 carbon; the other end has an unlinked 5 carbon.
What feature of mononucleotides provides the energy needed for polymerization when nucleic acids are formed?
their phosphate groups
You have a polymer of DNA with 10 adenine bases followed by 10 cytosine bases. If that strand bonded to a strand of 20 thymine bases, how would the double helix shape vary from a typical DNA double helix?
Only half of the molecule would have the double-helix shape.
DNA is composed of building blocks called _____.
In eukaryotic cells DNA has the appearance of a _____.
double helix
Which structure is not a component of a nucleotide?
Sulfhydryl Oxygen group
Which of the following statements about nucleotide structure is false?
The phosphate group is bonded to the nitrogenous base.
True or false? Guanine and uracil are examples of nitrogenous bases.
Which linkage forms the backbone of a nucleic acid?
A sugar-phosphate linkage
Which of the following statements about DNA structure is true?
The nucleic acid strands in a DNA molecule are oriented antiparallel to each other.
What is the complementary DNA sequence to 5' ATGCATGTCA 3'?
The interactions between nucleotides in an RNA double-stranded "stem" occur between what parts of the nucleotides?
nitrogenous bases
An RNA molecule that can catalyze chemical reactions is called a(n) _____.
If a strand of DNA has the nitrogen base sequence 5'-ATTTGC-3', what will be the sequence of the matching strand?
If a DNA double helix is 100 nucleotide pairs long and contains 25 adenine bases, how many guanine bases does it contain?
The two strands of a DNA double helix are held together by _____ that form between pairs of nitrogenous bases.
hydrogen bonds
A nucleotide is composed of a(n) _____.
phosphate group, a nitrogen-containing base, and a five-carbon sugar
DNA forms secondary structure only when two DNA strands align in antiparallel-instead of parallel-fashion. Which statement best explains why?
Bases on antiparallel strands form G-C and A-T pairs via hydrogen bonding; bases on parallel strands do not.
If a segment of DNA contains 28 percent T nucleotides, then the percentage of A nucleotides in that segment will be _____.
28 percent
Which of the following did Watson and Crick already know when they were trying to determine the structure of DNA?
The number of purines is always the same as the number of pyrimidines.
Franklin and Wilkins analyzed DNA by bombarding DNA crystals with X-rays. Their analysis yielded two numbers that sparked interest, 3.4 nm and 0.34 nm. What is the significance of these numbers?
These numbers tell us there are 10 rungs, or steps, on the DNA "ladder" for every turn of the helix.
In terms of structure and function how do DNA, RNA, and proteins compare?
RNA is intermediate between the complexity of proteins and the simplicity of DNA.