DNA Structure A
The building blocks of DNA are___________.
nucleotides
The nitrogenous base can be a _______, such as adenine (A) and guanine (G), or a pyrimidine,
purine; pyrimidine
The nucleotides combine with each other by covalent bonds known as ___________ or linkages.
phosphodiester bonds
In the 1950s, Francis Crick and ______________ worked together to determine the structure of DNA at the University of Cambridge, England.
James Watson
In Wilkins’ lab, researcher ____________ was using X-ray diffraction methods to understand the structure of DNA.
Rosalind Franklin
Watson and Crick proposed that DNA is made up of two strands that are twisted around each other to form a right-handed_____________
helix
The base pairs are stabilized by hydrogen bonds; adenine and thymine form two hydrogen bonds and cytosine and guanine form _________________
two hydrogen bonds
The two strands are anti-parallel in nature; that is, the ________ end of one strand faces the _______ end of the other strand.
3′, 5′
If comparing the structure of a DNA double helix to a ladder, what molecules make up the “rungs” or steps of the ladder and which make up the vertical sides of the ladder?
Responses
The rungs of the DNA ladder are made up of complementary nitrogenous bases and the sides of the ladder are made up of pentose sugars and phosphate groups.
The genetic information of an organism is stored in ___________.
DNA molecules
there are only four bases found in DNA:
G, A, C, and T.
What does the initials G, A, C, T, and U stand for?
guanine, adenine, cytosine, thymine, and Uracil
The human genome consists of around three billion nucleotides divided up between 23 paired ____________.
DNA molecules, or chromosomes
The information stored in the order of bases is organized into ___________.
genes
Genetic information is first copied to another nucleic acid polymer _________preserving the order of the nucleotide bases.
RNA
Genes that contain instructions for making proteins are converted to ___________.
messenger RNA (mRNA)
Other genes produce RNA molecules that are required for protein synthesis, ________________________.
transfer RNA (tRNA), and ribosomal RNA (rRNA).
the information stored in the DNA molecule must be _________ or expressed.
translated
Both copying and reading the information stored in DNA relies on base pairing between _________.
two nucleic acid polymer strands
The sugar deoxyribose with the _________ forms the scaffold or backbone of the molecule.
phosphate group
_________ is responsible for regulating blood sugar levels.
Insulin
If every human’s DNA has the same basic structure, then how do we all look different from one another and have different traits?
Responses
Our genetic information is a specific “code” which is found in our DNA. Everyone has a different sequence of nitrogenous bases in their DNA which make them unique from everyone else. The sequence of base pairs is our “genetic code”
Information stored in DNA must be ________ into specific functional products.
translated
If DNA of a particular species was analyzed and it was found that it contains 23 percent A, what would be the percentage of G?
27%
The sugar-phosphate backbone of a DNA double helix is joined together by ________ bonds.
phosphodiester