1. 1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Human Biology Sylvia S. Mader Michael Windelspecht Chapter 21 DNA Biology and Technology Lecture Outline Part 1

2. 2 DNA Biology and Technology

3. 3 Points to ponder What are 3 functions of DNA? Review DNA and RNA structure. What are the 3 major types of RNA and their functions? Compare and contrast the structure and function of DNA and RNA. How is DNA replicated? Describe transcription and translation in detail. Describe the genetic code. Review protein structure and function. What are the 4 levels of regulating gene expression?

4. 4 What did we learn from the Human Genome Project, and where do we go from here? What is ex vivo and in vivo gene therapy? Define biotechnology, transgenic organisms, genetic engineering, and recombinant DNA. What are some uses of transgenic bacteria, plants, and animals? Points to ponder

5. 5 What does DNA do? 1.It ___________ to be passed on to the next generation. 2.DNA ________ information. 3.It undergoes ___________ to provide genetic diversity. 21.1 DNA and RNA Structure and Function

6. 6 DNA structure: A review It is a ___________________. DNA is composed of repeating ____________ (made of a pentose sugar, phosphate, and a nitrogenous base). Sugar and phosphate make up the backbone, while the ________ make up the “rungs” of the ladder. Bases have _________________: cytosine (C) pairs with guanine (G), and adenine (A) pairs with thymine (T). 21.1 DNA and RNA Structure and Function

7. 7 DNA structure Figure 21.1 The structure of DNA. 21.1 DNA and RNA Structure and Function Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. T S P T S P P S P S S S S S S b. Ladder structurea. Double helixc. One pair of bases P S P P S S S P P O C C C C C T A G C T A C G A T T A A T deoxyribose 5′ end 3′ end 5′ end 3′ end 5′5′ 4′4′ 1′1′ 3′3′2′2′ 1′1′ 2′2′3′3′ 4′4′ 5′5′ 1′1′ 2′2′ 4′4′ 5′5′ phosphatepyrimidine basepurine base P P OH 3′3′ 3′3′ P P

8. 8 How is DNA replicated? The 2 strands unwind as the _________ are broken. Complementary nucleotides are added to each strand by DNA polymerase. Each new double-stranded helix is made of 1 new strand and one old strand (__________________________). The sequence of bases makes each individual unique. A A A A A A A A A A A A T T T T T T T T G G G G G G G G G G G G C C C C C C C C C C 21.1 DNA and RNA Structure and Function

9. 9 DNA replication Figure 21.2 Semiconservative replication. 21.1 DNA and RNA Structure and Function Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. A A A A A A A A A A A A A A A A A A A A T T T T T T T T T T T T T G G G G G G G G G G G G G G G G C C C C C C C C C C C C C A T T G C A T T G C C Daughter DNA double helix old strand 3′3′ new strand region of completed replication daughter DNA double helix old strand new strand 5′ region of replication: new nucleotides are pairing with those of parental strands region of parental DNA double helix DNA polymerase enzyme 3′3′5′

10. 10 RNA structure and function It ______________. RNA is composed of repeating nucleotides. Sugar-phosphate is the backbone. Bases are A, C, G, and _______ (U). 21.1 DNA and RNA Structure and Function

11. 11 3 types of RNA –______________ (mRNA) carries genetic information from DNA to the ribosomes. –______________ (rRNA) joins with proteins to form ribosomes. –____________ (tRNA) transfers amino acids to a ribosome where they are added to a forming protein. 21.1 DNA and RNA Structure and Function RNA structure and function

12. 12 RNA structure Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. S S S S G U A C G U A C ribose one nucleotide P P P P Base is uracil instead of thymine. Figure 21.4 The structure of RNA. 21.1 DNA and RNA Structure and Function

13. 13 Types of RNA Figure 21.9 The roles of all three forms of RNA in translation. 21.1 DNA and RNA Structure and Function Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. UCA UG GA U G C large ribosomal subunit a. An mRNA is threaded between ribosomal subunits and a polypeptide extends to the side. mRNA tRNA P site anticodon polypeptide b. A ribosome has two binding sites where codons bind to anticodons. A tRNA bearing a polypeptide is at the P site. A new tRNA amino acid is approaching the A site. c. A tRNA amino acid is coming to the ribosome. Upon arrival, its anticodon, CUG, will bind to its codon, GAC. anticodon A site codon val tryp ala ser met small ribosomal subunit asp C A