Modern Biology 10-2 DNA Structure
If 15% of the nucleotides in a DNA molecule contain guanine, what percentage of the nucleotides contain each each of the other three bases?
Since guanine and cytosine are complementary, another 15% of the nucleotides must contain cytosine. The remaining 70% of the nucleotides (100%-30%) must contain adenine and thymine in equal proportions (35% each), since they are complementary to each other
nitrogenous base
a base in DNA containing nitrogen and carbon
Purine
a nitrogenous base with two rings of carbon and nitrogen atoms. Examples may include adenine or ganine
Why is complementary base pairing important in DNA structure
because the hydrogen bonds between the bases hold the two strands of DNA together and because it serves as a way for DNA to replicate
According to the base-pairing rules, guanine binds with
cytosine
What are the three parts of the DNA nucleotide, and how are they connected to each other
deoxyribose sugar, a phosphate group, and a nitrogenous base. The phosphate group and the base are connected to different parts of the sugar
the percentage of adenine in DNA is
equal to the percentage of thymine
The two strands of a DNA molecule are held together by
hydrogen bonds
pyrimidine
nitrogenous base with one ring of carbon and nitrogen atoms. Examples may include cytosine or thymine
complementary base pair
pair of nitrogenous bases connected to each other by hydrogen
The primary function of DNA in cells is to
store information that tells the cells which proteins to make
How did X-ray diffraction photographs help Watson and Crick determine the structure of DNA
they showed that the shape of the DNA molecule was a double helix