DNA (Deoxyribonucleic Acid)

1. DNA (Deoxyribonucleic Acid) RNA (Ribonucleic Acid)

3. P P P Both DNA and RNA • Are Nucleic Acids • Macromolecules essential for Life • Have backbones of made of a sugar and phosphate group

4. Both have contain four nitrogenous bases attached to the backbone • Only certain bases are a part of DNA and RNA • The phosphate group, sugar and nitrogen bases make a nucleotide.

5. Phosphate Group O O=P-O O 5 CH2 O N Nitrogenous base C1 C4 Sugar C3 C2 Nucleotide

6. What makes DNA and RNA different from each other? • Structure (Single or Double stranded) • The sugar (Deoxyribose or Ribose) • Nitrogenous Bases on the Nucleiotide (ACTG or ACUG) • Function in the organisms (Holding information to code for specific protein that determines an organism’s traits, OR to copy instructions on how the protein should be assembled)

7. DNA vs. RNA • DNA • Double Helix (double stranded • Looks like a twisted ladder

8. 5 O 3 3 O P P 5 5 G C O 1 3 2 4 4 2 1 3 5 O P P 3 5 O O 5 P P 3 • DNA • Sugar is Deoxyribose • This gives DNA it’s name of Deoxyribonucleic Acid. A T

9. C T A G • DNA • Nitrogen bases are • Adenine (A) • Thymine (T) • Cytosine (C) • Guanine (G) • A always pairs with T • G always pairs with C

10. H-bonds G C A T BASE-PAIRINGS =Very weak bonds

11. DNA • The function of DNA is to hold the information that codes for certain proteins which determine an organism’s traits. • It is the master copy of information for the organism. When the cell is replicated it has to make copies of its DNA before it can divide. • This process is called DNA replication.

13. DNA Replication • DNA must be copied before a cell can divide. • This is called DNA Replication. • The DNA molecule produces 2 IDENTICAL new complementary strands following the rules of base pairing: A-T, G-C • Each strand of the original DNA serves as a template for the new strand

14. DNA Template Parental DNA New DNA DNA Replication Watson and Crick showed: the two strands of the parental moleculeseparate, and each functions as a template for synthesis of a new complementary strand. .

15. A---? • G---? • C---? • T---? • A---? • G---? • A---? • G---? • C---? • A---? • G---? • T---?

16. A---T • G---C • C---G • T---A • A---T • G---C • A---T • G---C • C---G • A---T • G---C • T---A

17. DNA vs. RNA • RNA • Single stranded • Looks like one-half of a zipper

18. RNA • Ribose sugar • This is where RNA gets it’s name of Ribonucleic Acid. Ribose

19. RNA • Nitrogen bases are • Adenine (A) • Uracil (U) • Cytosine (C) • Guanine (G) • A always pairs with U • G always pairs with C

20. Remember that DNA holds the instructions for making proteins that code for certain traits of an organism. • RNA copies the instructions, carries it to the appropriate part of the cell and translates it into the amino acids that code for proteins. • RNA takes the info from DNA to make proteins

21. Car Analogy From DNA to Proteins • One type of RNA, messenger RNA, copies the information from DNA in the nucleus, and brings these instructions to the cell’s factory floor, the cytoplasm. This process is called Transcription. 2. On the factory floor, mRNA moves to the assembly line, a ribosome.

23. 3. The ribosome, made of Ribosomal RNA, binds to the mRNA and uses the instructions to assemble the amino acids in the correct order. 4. The third type of RNA, transfer RNA is the supplier. tRNA delivers amino acids to the ribosome to be assembled into a protein. This is called Translation.

24. Three nitrogen bases on mRNA= a codon • Three nitrogen bases on tRNA= an anticodon • Codon and Anticodons code for amino acids that make proteins.

27. Genetic Diversity… • Different arrangements of NUCLEOTIDES in a nucleic acid (DNA) provides the key to DIVERSITY among living organisms.

28. Genetic Changes • DNA controls the structure and function of the cell. • So what happens when the sequence of DNA nucleotides in a gene is changed? • A substituted base in the DNA molecule changes the structure of a protein • Sometimes it may have little or no harmful effect. • Other times, however, the change can cause the cell to behave differently causing cancers or other harmful effects.

29. Causes of Mutations • Errors in replication • Errors in transcription • Errors in cellular division • Or by external agents (environmental factors) • Too much exposure to radiation • Pollutants • Nutritional deficiencies

30. Gene Mutations • Point Mutations – changes in a single base part of nucleotides • Substitution • THE FAT CAT ATE THE RAT • THE FAT HAT ATE THE RAT

31. Gene Mutations • Frameshift mutations- are mutations in which a single base is added to or deleted from DNA.

32. Gene Mutations • Frameshift Mutations – shifts the reading frameof the genetic message so that the protein may not be able to perform its function. • Insertion • THE FAT CAT ATE THE RAT • THE FAT HCA TAT ETH ERA T • Deletion • THE FAT CAT ATE THE RAT • TEF ATC ATA TET GER AT H H

33. Repairing DNA • Much like a book editor, enzymes proofread the DNA and replace incorrect nucleotides with correct nucleotides. • These work well, but they are not perfect.

34. Mutations in Reproductive Cells • If a mutation occurs in a reproductive cell of an organism and this cell takes place in fertilization, the altered gene would be passed on to the offspring. • Usually this is harmful to the offspring, BUT occasionally the gene mutation has a positive effect making them more likely to survive. • This can contribute to the evolution of the species.

35. Mutations in the Body Cells • If a mutation occurs in a nonreproductive cell of the body such as in the skin, muscle or bone, the mutation would not be passed on to the offspring. • The damage of the gene may impair the function of the cell. • If the mutation affects the cells ability to control cellular division, the cell may begin to divide uncontrollably resulting in cancerous tumors.