Biology Unit 3 study Guide

What is DNA?
the hereditary material in almost every organism on earth. Double helix shaped. in Nucleus/ chromosomes

3 components of DNA
a sugar molecule, a phosphate molecule, and a chemical base.

DNA is a polymer
(large molecule made up of smaller molecules called monomers); the sugar, the phosphate, and the chemical base are the monomers
.1 sugar + 1 phosphate + 1 base = 1 nucleotide

4 Bases of DNA
Codeadenine (A), guanine (G), cytosine (C), and thymine (T). like a code.

Sides of the ladder
Backbone.are repeating, alternating sequences of sugar and phosphate (s-p-s-p-s-p…)

rungs of the ladder
two bases that are bonded together by a hydrogen bond

DNA pairs
adenine (A) ALWAYS pairs with thymine (T)
A-T is connected by 2 H bonds
guanine (G) ALWAYS pairs with cytosine (C)
G-C is connected by 3 H bonds

broken into two parts “Deoxyribo” and “nucleic acid.” The “Deoxyribo” part refers to the type of sugar molecule.

deference between RNA and DNA
DNA has no oxygen while RNA has oxygen