Honors Biology Unit 9 Voabualary

replication

The process by which DNA makes a copy of itself before cell division, ensuring that each new cell receives an identical set of genetic information.

deoxyribose

A sugar molecule that is a component of DNA, consisting of a five-carbon structure and lacking one oxygen atom compared to ribose.

nucleotide

A building block of DNA and RNA, consisting of a nitrogenous base, a sugar, and one or more phosphate groups.

doubl helix

The structure of DNA consisting of two intertwined strands forming a spiral shape, where the sugar and phosphate backbone is on the outside and the nitrogenous bases are paired on the inside.

DNA Polymerase

An enzyme that synthesizes new DNA strands by adding nucleotides to a growing chain during DNA replication.

DNA

A double-stranded molecule that contains the genetic instructions for the development and functioning of living organisms, composed of sequences of nucleotides.

Roslind Franklin

A pioneering British scientist known for her critical contributions to the understanding of the molecular structures of DNA, RNA, viruses, coal, and graphite. Her X-ray diffraction images of DNA led to the discovery of its double helix structure.

Francis Crick

A British biologist and co-discoverer of the double helix structure of DNA alongside James Watson, who proposed the complementary base pairing mechanism.

James Watson

An American biologist and co-discoverer of the double helix structure of DNA with Francis Crick, known for his role in elucidating the molecular structure and function of DNA.

hydrogen bond

A type of weak chemical bond formed between an electronegative atom, such as oxygen or nitrogen, and a hydrogen atom. Hydrogen bonds are crucial in stabilizing the structures of proteins and nucleic acids like DNA.

base pairing rules

• Adenine (A) always pairs with Thymine (T) via 2 hydrogen bonds.

• Guanine (G) always pairs with Cytosine (C) via 3 hydrogen bonds.

• Purines (double-ring structures: Adenine and Guanine) always pair with Pyrimidines (single-ring structures: Thymine and Cytosine) to maintain a uniform width along the DNA ladder.

Semiconservative

the method of DNA replication where a double stranded molecule separates into two-single strands, and each strand acts as a template to build a new complementary strand

helicase