DNA "The Blueprint of Life"

DNA stands for... DeoxyriboNucleic Acid

DNA FACTS Shape is a double helix   established by James Watson and Francis Crick in 1953

codes for your genes  (traits) made of repeating subunits called nucleotides

What is a nucleotide? Base Sugar Has three parts: PHOSPHATE DEOXYRIBOSE (sugar) BASE  (A,T,G,C) Phosphate Base Sugar

Nitrogenous Bases Purines (double ring) Adenine Guanine Pyrimidines (single ring) Cytosine Thymine

Complimentary Base-Pair Rule The sides of the DNA ladder are phosphate & deoxyribose sugar held together by  hydrogen bonds

Base Pair Rule One side:     A   T   A      T   C   A      T   G   C      G   G   G Other side:

What is the relationship between GENES and DNA?

How the Code Works The combination of A,T,G,C determines what traits you might have..... C A T C A T   =  purple hair T A C T A C  =  yellow hair

Think of the bases of DNA like letters. Letters form words.... Words form sentences....                 *endless                combinations

DNA REPLICATION the process by which DNA makes a copy of itself Where: nucleus When: cell division SEMI-CONSERVATIVE half of the old (parent) strand is saved DNA Helicase: unwinds and unzips the DNA DNA Polymerase: adds new complimentary bases to the old (parent) stands

Let's Review What We Know About DNA 1.  DNA stands for:   De _____ ribo ______  acid 2.  What is the shape of DNA? ______________ 3.  Who established the structure of DNA?  ____________ and ______________ 4.  Adenine always pairs with _______________ 5.  The sides of the DNA ladder are deoxyribose and _______________

6.  Guanine always pairs with _____________ 7.  What is the complementary sequence:   C A T  T  A G 8.  The two sides of DNA are held together by _______ bonds. 9.  DNA is composed of repeating subunits called ______________________ 10.  What are the 4 bases that make up the rungs of the DNA ladder? ____________________

Draw Replication… Use this picture to help you start: I have unzipped the first 15 bases on each strand for you. Continue to unzip the DNA and create the new complimentary strands. G C A T G C A G G A T C T G A A T G G C G C C C T T G A G T Helicase T A C C G C G G G A A C T C A C G T A C G T C C T A G A C T

RNA - the messenger   *single stranded *ribose sugar *contains no thymine, uracil instead *follows base pair rule, but A ⇒ U DNA:   A  T  A   G  A  G RNA:   U A U C U C

mRNA carries the "message" from the DNA to the ribosomes, where proteins are made

Makes up the structure of the ribosome.

Transports the amino acids to the ribosome creating a sequence connected by peptide bonds to make the protein.

What is a gene? A section of DNA, with many bases that codes for a protein Proteins are the building blocks for organisms…TRAITS

How do we get from DNA to a protein?

DNA --> RNA --> Protein Protein Synthesis DNA -->  RNA -->  Protein

Transcription -  process where RNA is made from DNA Occurs in the nucleus (only reads one strand of the DNA) The messenger RNA (mRNA) is able to leave the nucleus through the semi-permeable nuclear membrane.

Let’s Practice Transcription… If this is your DNA, what would the complementary RNA strand look like: DNA: T A C G C T A A A G T G RNA: DNA: T A C A G C T A T A C A A U G C G A U U U C A C A U G U C G A U A U G U

Translation - process where proteins are made from RNA

Translation The mRNA attaches to a ribosome that “reads” the code from the DNA. The code occurs in the three letter sections called Codons.

The ribosome “calls” the complimentary tRNA anticodon to match up with the mRNA codon.

Translation Every protein created begins with the START codon AUG. AUG codes for the amino acid methionine. Every protein ends with the STOP codon, UGA, UAA, or UAG.

How do I know which codon calls which protein?

Let’s Practice Translation… Messenger RNA: A U G U U C G C A Amino Acid (AA): Messenger RNA: A U G C U A U A A Messenger RNA: A U G A C C G U G Meth. Phe. Ala. Meth. Leu. Stop Meth. Thr. Val.