The Role and Structure of RNA - Mrs. West

Nucleic Acids DNA vs. RNA Chapter 12-3 Nucleic Acids There are 2 types of nucleic acids.

DNA RNA

All living organisms have both DNA and RNA. Nucleic acids are made of nucleotides. They carry genetic information. DNA vs. RNA DNA

Deoxyribonucleic acid Double-stranded Sugar = deoxyribose Nucleotide Bases: Adenine Thymine Guanine Cytosine

RNA Ribonucleic acid Single-stranded Sugar = ribose Nucleotide Bases: Adenine Uracil Guanine

Cytosine DNA DNA Nitrogen Bases

G bonds to C A bonds to T G and A are purines C and T are

pyrimidines DNA Nucleotide Structure DNA Double Helix 2 strands wrapped around each other

Strands are twisted because of the bonding of pyrimidines to purines DNA Double Helix

Strands are oriented in opposite directions 3 to 5 OR 5 to 3

Function of DNA DNA can be copied, but that does NOT explain how a gene works. DNA contains coded instructions for making

proteins. The first step of making proteins is decoding the genetic messages by copying the nucleotide sequence from DNA into RNA. RNA

RNA Nucleotide Structure Ribose RNA Single Helix 1 twisted strand 3 Types

mRNA Messenger RNA tRNA Transfer RNA rRNA

Ribosomal RNA Functions of RNA

In most cells RNA molecules have just one job protein synthesis. All 3 types of RNA are involved in protein synthesis. Amino acids are the building blocks of proteins. The assembly of amino acids is controlled by RNA.

mRNA Messenger RNA serve as messengers from DNA to the rest of the cell. They carry copies of

the instructions found on genes. tRNA tRNA takes the messages from mRNA

and decodes them for the ribosome. During the construction of a protein, transfer RNA transfers each amino acid to the ribosome. rRNA

Proteins are assembled on ribosomes.

Ribosomes are made up of ribosomal RNA. Ribosomal RNA helps build the actual protein. rRNA puts together the amino acid messages carried by mRNA and decoded by tRNA. DNA vs. RNA Venn Diagram

DNA Bot h RNA