This lesson will increase your knowledge of concepts covered in the following TEKS for biology:

1. This lesson will increase your knowledge of concepts covered in the following TEKS for biology: 3.c – Evaluate impact of research on scientific thought, society, and the environment 3.f – Research and describe the history of biology and contribution of scientists 4.a – Identify the parts of a cell 6.a – Describe components of DNA and illustrate how information for specifying the traits of an organism is carried in the DNA 6.b – Explain replication, transcription, and translation using models of DNA and RNA 6.f – Identify and analyze karyotypes 10.a – Interpret the functions of systems in organisms 10.b – Compare the interrelationship of organ systems to each other and to the body as a whole

2. Previous LessonHuman Development and Stem Cells

3. Question: What two major processes must occur for a zygote to develop into an adult human being?

4. Human Development Involves • Addition of more cells through mitosis • Creation of adult cells with special functions through cell differentiation, creating about 210 different tissues in the body

5. Question: What is a stem cell and why does it have potential to revolutionize medicine?

6. Potential of Stem Cell Research Based on: Time, July 23, 2001

7. Question: Why is there a controversy over embryonic stem cells?

8. Fig. 22.12 Embryonic stem cells are undifferentiated cells in the blastocyst

9. Fig. 22.12 Harvesting of embryonic stem cells means destruction of an embryo that could live if implanted in the uterus Excess blastocysts from fertility clinics

10. Question: Describe other sources for stem cells.

11. Today’s LessonDNA and the Human Genome Project

12. Human Development Gene Therapy DNA Fingerprinting Cancer DNA Cloning Genetic Diseases Individualism Human Genome Project

13. THE BIG PICTURE DNA is the Blueprint for Life Each person has a unique complement of DNA Each person to have a unique complement of proteins Each person having a unique appearance and behavior which causes which contributes to

14. Overview of Lesson • Humans as hunks of protein • DNA and protein synthesis • Human genome project

15. Humans may be made of up to 2 million different types of proteins • Functions of Protein • Structural • muscle, hair • Chemical • antibodies, hormones, enzymes All of the chemical reactions in cells are regulated by enzymes

16. What are proteins made of? Proteins are chains of amino acids, usually a few hundred amino acids long AA AA AA AA AA AA AA AA

17. Examples of Amino Acids Based on: Mader, S. Inquiry Into Life, McGraw-Hill

18. Formation of a Protein Note: a chain of amino acids is forming as water is removed and amino acids bond together Based on: Mader, S. Inquiry Into Life, McGraw-Hill

19. Protein structure is more than just a chain of amino acids Based on: Mader, S. Inquiry Into Life, McGraw-Hill

20. Question: How do we make millions of different proteins out of only 20 different amino acids? Answer: The identity and function of each protein is determined by its amino acid sequence and folding

21. Amino Acid Sequence of Hemoglobin Normal hemoglobin Sickle-cell hemoglobin Box shows the one amino acid difference in normal versus sickle-cell hemoglobin

22. Red Blood Cells Microsoft ClipArt Based on: Harvard Family Health Guide, 1999

23. How Do We Get Amino Acids? • Eleven of 20 amino acids can be made by the human body • Nine of 20 amino acids cannot be made by the human body. These nine are the “essential amino acids” that must be included in the diet on a daily basis

24. Overview of Lesson • Humans as hunks of protein • DNA and protein synthesis • Human genome project

25. The structure of DNA (deoxyribonucleic acid) was discovered in 1950s by Watson, Crick, Wilkins and Franklin DNA has a ladder-like shape Based on: Mader, S. Inquiry Into Life, McGraw-Hill

26. DNA is not a protein, but rather it is the instructions for making proteins

27. DNA Structure Based on: Mader, S. Inquiry Into Life, McGraw-Hill

28. Why is DNA shaped like a ladder?

29. Proteins which are linear sequences of amino acids DNA contains a linear base code that… G - C Amino acid T - A Controls production of… C - G Amino acid A - T A - T Amino acid

30. The Way DNA’s Code WorksThree nucleotides in DNA code for one amino acid in a protein

31. DNA REGULATION OF PROTEIN SYNTHESIS Sequence of bases in DNA are read as triplet codes codes for C G C T A A C G A Amino acid Amino acid Amino acid

32. So how does DNA regulate protein synthesis in a cell?

33. DNA is part of the chromosomes in cells Humans have 23 pairs or 46 chromosomes in each cell Each chromosome has specific genes Most genes code for the production of specific proteins Based on: Mader, S. Inquiry Into Life, McGraw-Hill

34. DNA Control of Protein Synthesis in Each Cell of the Body DNA in the chromosomes of the nucleus Determines Protein synthesis at the ribosomes

35. Animal Cell Based on: Raven et al., Biology, McGraw Hill • Chromosomes (containing strands of DNA) are in nucleus, the control center of cell • Proteins are made at ribosomes, the protein manufacturing sites of cell

36. DNA Control of Protein Synthesis DNA uncoils and one strand is used to produce messenger RNA (mRNA) in nucleus mRNA leaves the nucleus and goes to the ribosomes with copy of blueprint at the ribosomes, amino acids are linked together as specified by the nucleotide sequence of the mRNA

37. DNA & PROTEIN SYNTHESIS Based on: Mader, S. Inquiry Into Life, McGraw-Hill

38. Messenger RNA Codons Based on: Mader, S. Inquiry Into Life, McGraw-Hill

39. Construction of a Building Blueprint in the foreman’s office contains the instructions for the building Workers take information from the office to the building site Workers assemble the building out of concrete and steel

40. Overview of Lesson • Humans as hunks of protein • DNA and protein synthesis • Human genome project

41. The Human Genome • Defined as the sum total of genes in a human • Estimates are 30,000 genes in each human controlling production of approximately 2 million different proteins • Each gene consists of an average of several thousand bases • Total number of nucleotides is about 3 billion per human cell

42. Human Genome Project • The project began in the late 1980s • supported by 15 billion dollars • Goal of the project was to sequence the • roughly 3 billion chemical letters in DNA • that comprise the genetic code of humans • Many scientists said it could not be done • Project was completed in 2000 • - or was it?

43. What We Don’t Know about DNA • The sequence of letters in DNA for the human genome is known, but the gene-protein relationships are unknown • It is like having the numbers in a phone book without the associated names • We are learning the identity of new genes each day

44. Human Proteome Research • Scientists will take decades to • figure out which proteins go with • which genes • All of today’s medicine will seem • medieval once proteomics studies • begin to link proteins and genes • because many human diseases are • genetically based

45. Next Lesson Individuality and Cloning