Nucleic Acids

Nucleic Acids

• Macromolecules made up of nucleotide subunits• Found in all living things and viruses• Two most common are: • Deoxyribonucleic acid (DNA)• Ribonucleuic acid (RNA)

Nucleotides

• Consists of • A phosphate group• A pentose (5 C sugar)• A nitrogenous base

• Purine: the nitrogenous base is double ring• Pyrimidine: the nitrogenous base is single ring

Nucleic Acid Strands

• Nucleotides bond together through dehydration synthesis • Phosphate group of one nucleotide and the sugar

on the next nucleotide

DNA

Used for carrying hereditary information and the recipe for making proteins.

Contains deoxyribose Has four different nucleotides

Adenine and Guanine are purines Cytosine and Thymine are

pyrimidines.

DNA Structure

The shape of DNA is a double helixTwo nucleotide strands run

anti-parallel to each otherLooks like a twisted ladder

The sugar and phosphate groups make up the sides

The nitrogenous bases make up the rungs.

Nitrogenous bases held together by hydrogen bonds

Complimentary Base Pairing• A always binds with T • They can both make 2

hydrogen bonds

• C always binds with G • They can both make 3

hydrogen bonds

RNA

• Single stranded• Generally shorter than DNA• Uses Adenine, Cytosine, Guanine, and Uracil

instead of Thymine• Contains ribose (instead of deoxyribose)

Three Types of RNA

• Messenger RNA (mRNA)• Transports the “message” of DNA from the nucleus to

the ribosome

Three Types of RNA

• Transfer RNA (tRNA)• Brings amino acids to

the ribosome to be incorporated into the newly forming polypeptide chain

Three Types of RNA

• Ribosomal RNA (rRNA)• Makes up a part of ribosomes, which makes proteins