DNA The Structure of DNA http://academy.d20.co.edu/kadets/lundberg/images/biology/dna21.gif – DNA image The Structure of DNA

Name the organelle and give its function. Nucleus: control body of the cell; contains the genetic material (DNA) Ribosome: site where proteins are made Golgi Aparatus: modifies, sorts, and packages materials from the ER for storage in the cell or secretion outside the cell Endoplasmic Reticulum: aids in processing carbohydrates, lipids and proteins for export from the cell Plant Animal Endoplasmic Reticulum Once a protein synthesized on a membrane-bound ribosome, it passes across the membrane of ER where the protein is processed by enzymes and folded into its correct three-dimensional conformation. Following the ER, the protein enters the Golgi apparatus where it is further modified by the addition of polysaccharide chains and packaged into vesicles. The ultimate fate of the protein is to be secreted out of the cell via exocytosis of the vesicles. Nucleus Golgi Body Ribosome

What is located in the nucleus? What type of organic compound is DNA? What is the monomer of DNA?

They all share a universal genetic code. What does the DNA of all these organisms have in common? The answer – Universal genetic code They all share a universal genetic code.

What is the name of these monomers? C amine group carboxyl group variable R group N H O R C amine group carboxyl group To what organic compound group do they belong?

Polypeptide Chain – A Protein What does the chain of amino acids represent? Threonine Arginine Glycine Proline Asparagine Alanine Polypeptide Chain – A Protein

History of Heredity Why am I so gorgeous?

Gregor Mendel But, I haven’t figured out how this happens Gregor Mendel determined that traits were passed from generation to generation.

Frederick Griffith Griffith was working on a vaccine for Streptococcus pneumoniae He worked with 2 strains of the bacteria: Smooth capsule that causes disease Rough capsule that does not cause disease

Frederick Griffith He added these bacteria strains, some dead and some living, to lab rats. These are his results:

Frederick Griffith Live Smooth Bacteria Live Rough Bacteria Dead Smooth Bacteria Live R+ dead S Bacteria

Griffith Proved: That somehow the dead bacteria have passed their disease-causing substance to the harmless, living bacteria. Griffith discovered a factor that could transform harmless bacteria into disease-causing bacteria

DNA What was this substance called? http://academy.d20.co.edu/kadets/lundberg/images/biology/dna21.gif

Oswald Avery Avery’s team determined that genes are composed of DNA

Erwin Chargaff Chargoff discovered that DNA has the same amount of adenosine as thymine and the same amount of cytosine as guanine. A = T and G = C A T C G

Rosalind Franklin & Maurice Wilkins Franklin and Wilkins used x-ray to discover that DNA was a double helix.

Watson and Crick Watson & Crick won a Nobel Prize for discovering the structural model of DNA. They credited Wilkins and Franklin. Wilkins also got a Nobel Prize but Franklin did not. Rosalind had passed away and the Nobels are not awarded posthumously. 1953

DNA is a Nucleic Acid What is a nucleic acid? Nucleic acids are one of the major organic compounds.

Auld Lang Syne! Nucleic acids contain C, H, N, O, P Are made up of nucleotide monomers sugar phosphate nitrogen base Store genetic information Help make proteins Examples: DNA & RNA NUCLEIC ACIDS very large linear molecules made up of nucleotides containing C, H, N, O, P store genetic information, help to make proteins examples: DNA and RNA DeoxyriboNucleic Acid

DNA Structure For what does DNA stand? What is the monomer for nucleic acids? What is the structure of this monomer? phosphate nucleotide sugar nitrogen base The numbers are the positions of the carbons on the sugar. (the 3’ end) 5 4 3 2 1 (the 5’ end) N base PO4 Sugar PO4 N base Sugar DeoxyriboNucleic Acid

A NUCLEOTIDE 3. Nitrogen Base 1. Phosphate Group 3. Nitrogen Base 2. 5-Carbon Sugar (Dexoyribose or Ribose) 1. Phosphate Group 2. 5-Carbon Sugar (Dexoyribose or Ribose) 1. 2. 3. 3. Nitrogen Base H H2 H3 O C N P 1. 2. 3. Nucleotides, too

Nucleotides A G T C Adenine Purines Guanine Thymine Pyrimidines There are four nitrogen bases making up four different nucleotides. A Adenine Purines Guanine G N base T Thymine Pyrimidines Cytosine C

Chargaff’s Base Pair Rules Adenine always bonds with thymine. Adenine (A) to Thymine (T) A T The lines between the bases represent hydrogen bonds C G Guanine always bonds with Cytosine. Guanine (G) to Cytosine (C)

Pairing DNA Nucleotides What is a nucleotide? What is the base pairing rule? What would be the complementary nucleotide pairing? P N-b Nucleotide S C G Rule A Review slide. Make sure students can pick out the sugar, phosphate group, and nitrogen bases as well as know how the bases pair up (have them tell you the what the answers are before you animate it) A to T A C to G T G

3’End 5’End ladder shaped molecule DNA DOUBLE HELIX

Purpose of DNA Why do we have DNA? DNA contains our genetic codes For what does it code? for proteins What actually makes you look the way you do - DNA or Proteins?

What is RNA? RNA stands for RiboNucleic Acid DNA must have a “helper” molecule. sugar phosphate nitrogen base RNA is a single stranded nucleic acid made up of monomers called nucleotides

RNA Nucleotides B A C A - Sugar (ribose) B - Phosphate C - Nitrogen base nitrogen base sugar phosphate B Name the parts of the nucleotide. RNA is made of nucleotide subunits arranged in a single strand Ask students which molecules are which (before you animate the answers) A C

RNA Identify the parts of the RNA strand. Nitrogen Base Sugar (ribose) Make sure students know the molecules located in RNA. Have the students notice that RNA is single stranded whereas DNA is a double helix. Sugar (ribose) Phosphate Group

Notice that RNA has Uracil (not thymine) Rules for Base Pairing Cytosine pairs with Guanine C = G Adenine pairs with Uracil A = U IMPORTANT!!!!!!! Notice that RNA has Uracil (not thymine)

Rules for Base Pairing C = G A = U C G A U G C T A 3’ DNA strand Teacher FYI – the transcription process moves from the 3’ end of DNA to the 5’ end and synthesizes an RNA strand of opposite polarity T A RNA strand 5’ DNA strand

What is the function of RNA? Carries DNA’s message code Helps make protein Types of RNA Messenger RNA (mRNA) Transfer RNA (tRNA) Ribosomal RNA (rRNA) Ask students the function of RNA; they should recall this from the organic molecules unit. Introduce the three types of RNA; you don’t need to give their functions here. Messenger (mRNA) Transfer (tRNA) Ribosomal (rRNA)

Comparing DNA & RNA DNA RNA √ √ √ √ Sugar is deoxyribose Sugar is ribose Adenine base is present Cytosine base is present √ √ √ Review the differences between DNA & RNA Have them tell you the answers to each before you animate the answers √

Comparing DNA & RNA DNA RNA √ √ √ √ Guanine base is present Thymine base is present Uracil base is present Shape is double helix √ √ √ Review the differences between DNA & RNA Have them tell you the answers to each before you animate the answers √

Comparing DNA & RNA DNA RNA √ √ √ √ Shape is single stranded Located in nucleus Located in cytoplasm Stores genetic information √ √ √ Review the differences between DNA & RNA Have them tell you the answers to each before you animate the answers √

Comparing DNA & RNA DNA RNA √ √ √ √ √ Functions in protein synthesis Composed of nucleotides Template for synthesis of proteins Transcribes the Template More than one type √ √ √ Review the differences between DNA & RNA Have them tell you the answers to each before you animate the answers You will probably have to tell them the answers to the 1st, 3rd & 4th question on this slide since they don’t know about protein synthesis yet; it will be a good review at the end of the chapter though. √ √