D.N.A.

1. D.N.A. DeoxyriboNucleic Acid A molecule that contains our genetic information Is found in the nucleus of almost all cells wound up into chromosomes.

2. DeoxyriboNucleic Acid Double Helix (Twisted Ladder) Watson and Crick Double stranded Made of Nucleotides: Sugar, Phosphate, Base Has 4 nitrogen bases: Adenine, Guanine, Thymine, Cytosine Combination of these bases (order) is what makes up our traits

3. Nucleotides

4. What are the 3 parts to a nucleotide?

6. Base Pair

7. Base Pair • Complete the DNA strand T A C G C C C G T T A T C A T A A ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Hydrogen Bonds!!!

8. Purines (Adenine, Guanine) double ring • Pyrimidines (Thymine, Cytosine) single ring

10. Replication • Why Replicate (copy)? • STEPS TO COPY DNA: • DNA UNWINDS • DNA UNZIPS • BASE PAIRS ARE ADDED TO BOTH STRANDS • 2 NEW DNA MOLECULES

11. Replication

12. DNA Polymerase – adds new bases Helicase – unzips (breaks hydrogen bonds) DNA

13. DNA molecule http://www.dnai.org/index.html Base Pairing http://gslc.genetics.utah.edu/units/basics/ Replication http://www.pbs.org/wgbh/aso/tryit/dna/index-nojs.html

14. RNA • Ribonucleic acid • RNA is a messenger for DNA. • RNA takes the genetic information from DNA and takes it to the ribosomes where it makes the proteins

15. 3 differences between RNA and DNA 1. RNA = ribose (does have oxygen) DNA – deoxyribose (does not have oxygen) 2. RNA has a single strand DNA has a double strand 3. RNA has uracil as a base instead of Thymine like DNA has

16. RNA • 3 types • messenger RNA – takes info from nucleus to ribosome • transfer RNA – transfers amino acids to ribosome to make proteins • Ribosomal RNA – makes up ribosomes

19. RNA

20. Protein Synthesis • http://www.pbs.org/wgbh/aso/tryit/dna/index-nojs.html

21. Protein Synthesis

22. Protein synthesis is transferring the information that DNA gives to mRNA. mRNA transfers that information to ribosomes

26. Why ribosomes? Because ribosomes makes proteins which is the foundation for all cells.

27. Yo! Ribo! • Once the mRNA leaves the nucleus, it travels in the cell looking for a ribosome • When the mRNA finds the ribosome, the ribosome binds onto the mRNA

28. ribosomal-RNA • Notice the split in the ribosomes – there is a small part and a large part. Each of those two parts is called a 'subunit' and is made up of many proteins and RNAs. • It's a special RNA made expressly for the purpose of using in ribosomes, called 'ribosomal-RNA‘ or rRNA.

29. Let's watch them make a protein, then we'll see the secret code and how it works. • The ribosome crawls along messenger-RNA and translates the genetic code into which amino acid belongs where. • Then it super glues the amino acids together. • The chain of super glued amino acids is called a protein.

30. CODONS • The ribosome only looks at three nucleotides in a row. • These three nucleotides are the code. They are like three letter words. In English, 'dog' and 'cat' and 'you' are three-letter words that mean different things. • Those scientists call a three-nucleotide 'word' a 'codon'. • Looky! Code is part of the word codon.

31. Lets make our own message using three-letter words • If we made this chain, someone would read the message and tell each person or animal where to get in line. • As each one got in the right order, the reader would tell them to hold hands, or paws, to keep them in the right order.

32. “The Code” • The ribosome does it slightly differently. • The ribosome needs help with the reading part. It gets that help from its cousins, the transfer-RNAs.

33. The transfer-RNA • The transfer-RNAs, help the ribosome read the three letter 'words' by having three nucleotides exposed on their bottoms. • These three nucleotides are called an anti-codon. • anti-codon because they fit exactly, like a puzzle piece, with my three-letter 'words' called codon.

34. So, that's really all there is to the genetic (secret) code • The secret is that messenger-RNA is really a string of three-letter 'words' that tell the ribosome what the correct order of the amino acids are in a protein

35. Here's the whole crew, doing their thing! Watch what happens! • The transfer-RNA floats in and if its anti-codon matches up with mRNA’s codon, it gives up the amino acid it was carrying. Then the ribosome super glues the new amino acid to the end of the amino acid chain it has been growing.