Structure and Function of DNA

DNA Replication and Protein Synthesis

Double Helix in Shape- two stands wound around one another.

Composed of subunits called nucleotides Parts of a Nucleotide

5 Carbon Sugar- Deoxyribose Phosphate Group Nitrogen Base (4 Flavors)

Adenine, guanine, cytosine, and thymine (A,T,C,G)

DNA Structure

Nucleotides of a DNA Molecule

Credited with Double Helix Model Spiral staircase or twisted

ladder Maurice Williams and

Rosalind Franklin worked with them also.

Watson and Crick

Chargoff’s Rule A,C,T, G always bind in a certain

way

Adenine- Thymine

Cytosine- Guanine

Hydrogen Bonds Hold Them Together

Base Paring

DNA stores all of the genetic information for the cell.

If it located in the nucleus but can also be found in the mitochondria and the chloroplast.

Serves as the blueprint for making proteins.

Function of DNA

Copying DNA to make an exact copy (in nucleus) DNA strand unwinds and separates Enzymes help new DNA chains form by using

nucleotides floating around the nucleus. Produces two new exact copies of the original

DNA strand. Occurs during S phase if interphase Remember A-T and C-G !!!

DNA Replication

http://www.google.com/url?sa=i&rct=j&q=dna+replication+animation&source=images&cd=&cad=rja&docid=yggFo-zcE1QxIM&tbnid=WWUU9yxBeeEZMM:&ved=0CAUQjRw&url=http://online.santarosa.edu/presentation/page/?48549&ei=ItF7UfWzFoLC4APAqYGADQ&bvm=bv.45645796,d.dmg&psig=AFQjCNEfZAIop_JxBaU-1fw8u3X5tMCr5Q&ust=1367155356645913

1. CTC GGG ATA CTG GGG CGT

2. ATG GCG CGT CGT CAT TAC

3. GTG CGT CAT CCC AAA TTT

4. TAC CAT ATC GTA CGT GTA

5. AAT TTA TAT CTC GTG CCC

Replication Practice

Ribonucleic Acid Structure of RNA

Made of nucleotides Sugar-Ribose Uracil Replaces Thymine and Pairs with

Adenine Single Strand not double Smaller than DNA

Part II: RNA

mRNA- messenger RNA Carries RNA info from nucleus to cytoplasm

tRNA- transfer RNA Picks up amino acids

rRNA- ribosomal RNA Makes up the ribosomes where proteins are

made.

Types of RNA

DNA VS. RNA

DNA RNA Occurs in the nucleus When the cell needs a protein is transcribes

a certain part of DNA into RNA. RNA is then the directions to make the

proteins.

Transcription

1. TAC GGC TAT ATC CTG CGC TAT ACG ATT

2. TAC CCG GAT CCG TTC ATA CGT ACT ATC

3. TAC GTA AAA AGT GGG CCC TAT GAT ATT

4. TAC GTA CGT CAT GAT TAG AGT TCT ATC

5. TAC GTA CTA GTA CCC GTA ATA AGA ATC

Transcription Practice

RNA is read in sets of 3 bases called codons.

Each codon CODES for a specific amino acid.

Start Codon –AUG Stop Codons- UAA,

UAG, UGA

The Genetic Code

Making proteins from the mRNA code. mRNA leaves the nucleus and moves to the

cytoplasm. Goes to the ribosome where it is read is sets

of 3 bases called a CODON. tRNA picks up amino acids needed to make

specific proteins

Translation

Structure of Proteins Polymers made of amino acids bonded by

peptide bonds. Specific sequence of amino acids makes each

protein. There are 20 different amino acids used to

make proteins.

Protein Synthesis

Once at the ribosome, the amino acids brought by the tRNA are bonded together by peptide bonds.

Bonded by peptide bonds. MAKES A PROTEIN.

Protein Assembly

SUMMARY

PROCESS MOLECULES LOCATION

REPLICATION

TRANSCRIPTION

TRANSLATION

Transcribe and Translate the following sequences. 1. DNA- TAC GGT ACT TAG AGA TTT AAA ATT RNA AA

2. DNA- TAC GTG GGG TTT ACT TCA CAT TTC GAG RNA AA

Translation Practice