Honors Biology Nucleic Acids Vocab

Nucleotides

The building blocks of nucleic acids that consist of a sugar, a phosphate, and a nitrogen base.

Nucleic acids

The 4th biomolecule essential to life

Nitrogen bases

A part of the building block for nucleic acids. In the case of DNA, holds the 2 strands together using hydrogen bonds. Examples are adenine, thymine (in DNA), guanine, cytosine, and uracil (in RNA).

Double-helix

The shape of DNA that resembles a staircase

Antiparallel

DNA strands are parallel, but in different directions– one strand is upside down.

Complementary base pairs

Nitrogen base adenine always pairs with either thymine or uracil, and cytosine always pairs with guanine.

Hydrogen bond

Attraction of H (+) ion to another atom by electrostatic charge; opposite charges attract (+ is attracted to -). This is seen between the nitrogen bases.

Covalent bond

When 2 atoms share electrons to fill their outer energy level and make up most molecules in the human body. This is seen between phosphates, sugar, and nitrogen bases.

DNA replication

The process by which a molecule of DNA is replicated

Semi-conservative replication

The two DNA copies have one original strand and one new one

Template strand

The strand that undergoes DNA replication first, nucleotides are added from top to bottom.

Lagging strand

The strand that undergoes DNA replication second, nucleotides are added from bottom to top.

Helicase

The enzyme that breaks the hydrogen bonds of DNA in replication.

DNA polymerase

The enzyme that replicates DNA to build a new strand.

Ligase

The enzyme that “glues” nucleotides together.

Cell cycle

The series of events that divides a cell into 2 daughter cells. Consists of interphase, mitosis, and cytokinesis.

Interphase

Longest part of the cell cycle where the cell grows and replicates DNA to prepare for separation. Includes G1, G0, S and G2 phases.

Mitosis

Process of the nucleus dividing, forming two nuclei with similar chromosomes. Includes prophase, metaphase, anaphase, and telophase.

Cytokinesis

Division of the cytoplasm that results in two cells with identical nuclei.

Cancer

Uncontrollable cell growth

Apoptosis

Programmed cell death