DNA Review

• The structure of DNA is a double helix, which is similar to a “twisted ladder.” It’s structure consists of a 5 carbon sugar called (deoxyribose), a phosphate group and one of four nitrogen bases (Adenine, Thymine, Cytosine or Guanine).

• The nitrogen bases hold the codes for proteins which determine our genetic traits.

RNA

The structure of RNA is a single strand nucleic acid involved in the making or proteins or Protein Synthesis.

It’s structure is made up of a 5 carbon sugar called Ribose, a phosphate group and one of four nitrogen bases (Adenine, Cytosine, Guanine and Uracil (takes the place of Thymine and pairs to Adenine)

There are 3 types of RNA:

mRNA – messenger RNA which is the transcriber.

tRNA - transfer RNA which is the transfer of amino acids and translator.

rRNA – ribosomal RNA which helps make up part of the Ribosomes.

Important Vocabulary Terms

• DNA Triplet: a 3 base section of DNA that carries the code for specific amino acids to make a protein.

• Codon: a 3 base section mRNA that codes for a specific amino acid (ex: AUG – start codon).

• Anticodon: a 3 base section of tRNA that complementary to mRNA (ex: UAC) and carries the amino acid.

Protein SynthesisProcess by which an organism’s genetic code (DNA) is translated into protein.

Two steps of Protein Synthesis

Info from DNA copied to a strand of mRNA

writes

Step 1: Transcription:

Info from mRNA used to form amino acid chains

(protein)

reads

Step 2: Translation:

Building RNA - Transcription

1.DNA must first unwind.

2. RNA Polymerase, an enzyme, separates strands of DNA exposing the nitrogen base pairs.

3. RNA Polymerase then matches RNA nucleotides with one side of the DNA template.

NO “T”

A U

C G

In RNA,

A bonds with T (on DNA strand), but U bonds with A (on RNA strand)

4. The mRNA is then spliced because DNA also carries information that does NOT code for proteins.

The spliced portion is called an Exon because this is the region of DNA that codes for protein & will exit nucleus

The Intron is the noncoding region of DNA that does NOT code for proteins and is spliced out and remains in the nucleus

5. The spliced mRNA leaves the nucleus & attaches to ribosomes in the cytoplasm.

rRNA

Translation: the building of proteins by using the information from mRNA.1. mRNA strand attaches to the ribosome and is used to translate into a protein.

2. tRNA molecules transfer amino acids to the ribosomes.

3. As tRNA bases pair up with mRNA, it leaves amino acids which are used to form the protein chain.

http://creationwiki.org/images/e/ed/Translation.JPG

REVIEW: What are 3 differences between DNA and RNA?

• DNA is double stranded • RNA is single stranded• DNA has Thymine • RNA has Uracil• DNA has Deoxyribose sugar• RNA has Ribose sugar