Chapter 10 Modern Genetics

Do Now: 1. Why is DNA called the blueprint for life?

VII. Modern Genetics DNA ~ Deoxyribonucleic Acid LOCATION : In the NUCLEUS ONLY of each cell   FUNCTION: Controls the production of proteins, enzymes & hormones; passes genetic information on to offspring

B. DNA STRUCTURE Made of repeating units called NUCLEOTIDES. One NUCLEOTIDE is made of 3 things: 1 5-carbon SUGAR called Deoxyribose 1 Phosphate 1 Nitrogen Base

1) There are four kinds of nitrogen bases:

C. WATSON & CRICK (1960’s) ~ Discovered the shape of DNA The shape is a DOUBLE HELIX (double spiral) 2 complimentary strands

What are the corresponding nucleotides for A C T G A T G C A

Hydrogen bonds in between the nucleic acids are WEAK so they can break apart when they are getting ready to replicate during cell division

D. DNA REPLICATION 1. Replication means to COPY exactly. 2. Happens during MITOSIS   3. DNA untwists and splits down the middle. Then new nucleotides fill in the “empty” places to form 2 new identical DNA molecules.

E. RNA ~ Ribonucleic Acid How is it different from DNA? *Different 5-carbon sugar called RIBOSE *No Thymine *Has Uracil instead of Thymine *Single Strand – Single Helix

2. Three Types of RNA mRNA – “Messenger Molocule” – copies from DNA in the nucleus and brings code to ribosomes

tRNA- “Transfer Molecule” – Gathers needed amino acids and brings them to ribosomes to make protein

rRNA- Helps make proteins in ribosomes

3. LOCATION & FUNCTION Location: mRNA in nucleus and can leave nucleus tRNA & rRNA near ribosomes Function: Protein Synthesis

4. PROTEIN SYNTHESIS Begins in NUCLEUS and ends in RIBOSOMES DNA is read and transcribed into a complementary strand of mRNA (copied from DNA language to RNA language). mRNA carries code to ribosomes

3. tRNA reads code and brings in the proper amino acids to make the protein. Amino acids are linked in the correct order to form a protein. **CODON – 3 nucleotide sequence in the mRNA **ANTICODON – complementary 3 nucleotide sequence in the tRNA EX: mRNA = AUG tRNA =

http://www.youtube.com/watch?v=h5mJbP23Buo

F. MISC. GENETICS STUFF The One Gene – One Polypeptide Hypothesis For every protein that needs to be made there is only ONE gene that has the code to make it.

2. Cloning – The production of genetically identical offspring using the cells of an already living organism. Controlled by humans.

Genetic Engineering – aka “Gene Splicing” - Transferring part of the genetic code from one organism to another. - Forms recombinant DNA - Used for disease research and treatments

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