DNA Structure Quiz

Restriction Enzymes

- Made by bacteria - Cut DNA at specific sequences - Usually at 6-base sequence - Sequence is specific for each enzyme - Cuts usually staggered-sticky ends (a few are blunt cutters)

Polynucleotide

A biopolymer comprised of monomeric units of nucleotides joined together in a chain.

Pyrimidine base

A crystalline organic base that is the parent substance of various biologically important derivatives. Any of several basic compounds is derived from or is structurally related to it, especially the nucleic acid constituents uracil, cytosine, and thymine.

Guanine

A purine base found in DNA and RNA; pairs with cytosine.One of the four bases, one of the constituent bases of nucleic acids, nucleosides and nucleotides. Symbol: G

Adenine

A purine base that is a component of DNA and RNA, forming a base pair with thymine in DNA and with uracil in RNA. Symbol: A

Cytosine

A pyrimidine base found in DNA and RNA that pairs with guanine. Symbol:

Thymine

A pyrimidine base, C5H6N2O2, that is one of the principal components of DNA, in which it is paired with cytosine. Symbol: T

Purines are

Adenine and Guanine and have 2 rings

Sugar (deoxyribose)

An aldopentose (i.e. a monosaccharide with five carbon atoms) derived from the pentose sugar ribose by the replacement of a hydroxyl group with a hydrogen atom at the 2 position, leading to the net loss of an oxygen atom (hence the name)

Sugar-phosphate backbone

Forms the structural framework of nucleic acids, including DNA and RNA. This backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.

Phosphate Group

It is found in the genetic material DNA and RNA, and is also in molecules such as adenosine triphosphate (ATP) that provide energy to cells. Negatively charged.

Monomer of DNA

Nucleotide

Nucleotide

One of the structural components, or building blocks, of DNA and RNA. Consists of a base (one of four chemicals: adenine, thymine, guanine, and cytosine) plus a molecule of sugar and one of phosphoric acid.

3 Parts of a Nucleotide

Phosphate, base, sugar

Difference between 5' and 3'

The 5' and 3' mean "five prime" and "three prime", which indicate the carbon numbers in the DNA's sugar backbone. The 5' carbon has a phosphate group attached to it and the 3' carbon a hydroxyl (-OH) group. This asymmetry gives a DNA strand a "direction"

Complimentary Base Pair

The chemistry of the nitrogenous bases is really the key to the function of DNA. It allows something called complementary base pairing. You see, cytosine can form three hydrogen bonds with guanine, and adenine can form two hydrogen bonds with thymine.

Double Helix

The description of the structure of a DNA molecule. A DNA molecule consists of two strands that wind around each other like a twisted ladder. Each strand has a backbone made of alternating groups of sugar (deoxyribose) and phosphate groups. Structure: Polymer

Hydrogen Bonds

The two strands of DNA stay together by these bonds, occurring between complementary nucleotide base pairs. Two bonds occur between the adenosine and the thymine base pairs, and between the cytosine and the guanine there are three.

Purine Bases

They include the nucleobases adenine (2) and guanine (3). In DNA, these bases form hydrogen bonds with their complementary pyrimidines, thymine and cytosine, respectively. ... In RNA, the complement of adenine is uracil instead of thymine.

Pyrimidines are

Thymine and Cytosine and have 1 ring