1. End Show 12–3 RNA and Protein Synthesis Slide 1 of 39 Copyright Pearson Prentice Hall 12–3 RNA and Protein Synthesis 106. What are genes? They are coded DNA instructions that control the production of proteins. 107. How does this happen? Genetic messages can be decoded by copying part of the nucleotide sequence from DNA into RNA. RNA contains coded information for making proteins.

2. End Show 12–3 RNA and Protein Synthesis Slide 2 of 39 Copyright Pearson Prentice Hall The Structure of RNA 108. What is the structure of RNA? It consists of a long chain of nucleotides. Each nucleotide is made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base. 109. What are the differences between the NA’s? The sugar in RNA is ribose instead of deoxyribose. RNA is generally single-stranded. RNA contains uracil in place of thymine. 110. What are the 3 types of RNA? Messenger (mRNA), transfer (tRNA), and ribosomal (rRNA).

3. End Show 12–3 RNA and Protein Synthesis Slide 3 of 39 Copyright Pearson Prentice Hall Types of RNA It carries copies of instructions for assembling amino acids into proteins from the nucleus to the ribosome (it’s the messenger or carries DNA’s message). 111. What is the function of mRNA?

4. End Show 12–3 RNA and Protein Synthesis Slide 4 of 39 Copyright Pearson Prentice Hall Types of RNA It and proteins make up the ribosome. Ribosome Ribosomal RNA 112. What’s the function of rRNA?

5. End Show 12–3 RNA and Protein Synthesis Slide 5 of 39 Copyright Pearson Prentice Hall Types of RNA During protein construction, it transfers each amino acid to the ribosome. It transfers DNA’s instruction into amino acid language. Amino acid Transfer RNA 113. What’s the function of tRNA?

6. End Show Slide 6 of 39 Copyright Pearson Prentice Hall Genes are coded ____ instructions that control the production of proteins. ____ is the molecule that makes proteins. What are the 3 differences in structure does RNA have that DNA does not? Match the following: 1.mRNAa. brings amino acids to ribosome 2.rRNAb. built in nucleus, carries DNA code 3.tRNAc. makes up part of the ribosome

7. End Show 12–3 RNA and Protein Synthesis Slide 7 of 39 Copyright Pearson Prentice Hall Transcription 114. What is transcription? It is the process where mRNA molecules are produced by copying part of a nucleotide sequence of DNA into a complementary sequence in RNA (when DNA’s code is copied or transcribed). 115. How does this occur. Transcription requires the enzyme RNA polymerase. 116. What does RNA polymerase do? RNA polymerase binds to DNA and separates the DNA strands during transcription. It then uses one strand of DNA as a template from which nucleotides are assembled into a strand of mRNA.

8. End Show 12–3 RNA and Protein Synthesis Slide 8 of 39 Copyright Pearson Prentice Hall Transcription 117. What are promoters and why are they important? They are the regions of DNA that RNA polymerase binds to. They are signals in DNA that indicate to the enzyme where to bind to make mRNA.

9. End Show 12–3 RNA and Protein Synthesis Slide 9 of 39 Copyright Pearson Prentice Hall RNA Editing 118. What are introns and exons? Introns – segments of eukaryotic DNA that are not involved in coding for proteins. Exons - the DNA sequences that code for proteins.The introns are cut out of RNA molecules. 119. What happens with introns and exons? Introns are removed, and the exons are the spliced together to form mRNA. Exon Intron DNA Pre-mRNA mRNA Cap Tail

10. End Show Slide 10 of 39 Copyright Pearson Prentice Hall What’s the name of the process where DNA’s instructions are copied and mRNA is formed? What is the name of the enzyme that unzips DNA and creates mRNA? Regions of DNA code that tell RNA Polymerase where to begin making proteins are called _____. The regions of DNA that don’t code for proteins are called ______. The regions that do code for proteins are called ______. Does mRNA include the intron (non-protein coding) segments of DNA?

11. End Show 12–3 RNA and Protein Synthesis Slide 11 of 39 Copyright Pearson Prentice Hall The Genetic Code 120. What is the language of the mRNA instructions? The genetic code (4 letters are used - the bases: A, U, C, and G). 121. What is a codon? It consists of three consecutive nucleotides on mRNA that specify for a particular amino acid.

12. End Show 12–3 RNA and Protein Synthesis Slide 12 of 39 Copyright Pearson Prentice Hall The Genetic Code 122. What do codons do? They specify for a particular amino acid that is to be placed on the polypeptide chain. 123. Can more than one codon ‘code’ for a single amino acid? Yes, some amino acids can be specified by more than one codon. 124. What are start and stop codons? There is 1 codon (AUG) that can either specify the amino acid methionine or serve as a “start” codon for protein synthesis, and there are 3 “stop” codons that do not code for any amino acid. These “stop” codons signify the end of a polypeptide.

13. End Show 12–3 RNA and Protein Synthesis Slide 13 of 39 Copyright Pearson Prentice Hall The Genetic Code

14. End Show 12–3 RNA and Protein Synthesis Slide 14 of 39 Copyright Pearson Prentice Hall Translation 125. What is translation? It is the decoding of an mRNA message into a polypeptide chain (protein). 126. Where does it happen? On ribosomes. 127. Describe translation. During translation, the cell uses information from messenger RNA to produce proteins. 128.When does it begin? It begins when mRNA attaches to a ribosome. As each codon of the mRNA molecule moves through the ribosome, the proper amino acid (aa) is brought into the ribosome by tRNA. In the ribosome, the aa is transferred to the growing polypeptide chain.

15. End Show 12–3 RNA and Protein Synthesis Slide 15 of 39 Copyright Pearson Prentice Hall Translation 129. How does tRNA know what aa to bring to the ribosome? Each tRNA molecule carries only one kind of aa. In addition to an aa, each tRNA molecule has 3 unpaired bases called the anticodon, which are complementary to one mRNA codon. 130. When does the polypeptide chain begin to form? When the ribosome encounters the start codon. 131. When does the polypeptide chain end? When the ribosome encounters the stop codon.

16. End Show Slide 16 of 39 Copyright Pearson Prentice Hall A _____ is a segment of 3 nucleotides that code for specific ____ _____ that are brought to the ribosome by tRNA. The decoding of an mRNA message into a polypeptide chain (protein) is the process known as __________. Each tRNA has its own code of ___ nucleotides and has to match with the ______ located on the tRNA. This is how tRNA knows which amino acid is needed.

17. End Show 12–3 RNA and Protein Synthesis Slide 17 of 39 Copyright Pearson Prentice Hall Translation Lysine tRNA Phenylalanine Methionine Ribosome mRNA Start codon The ribosome binds new tRNA molecules and amino acids as it moves along the mRNA.

18. End Show 12–3 RNA and Protein Synthesis Slide 18 of 39 Copyright Pearson Prentice Hall Translation Protein Synthesis tRNA Ribosome mRNA Lysine Translation direction

19. End Show 12–3 RNA and Protein Synthesis Slide 19 of 39 Copyright Pearson Prentice Hall The Roles of RNA and DNA 132. How are DNA and RNA related to protein synthesis? The cell uses the DNA instructions to create RNA (mRNA). The DNA stays in the nucleus. mRNA leaves the nucleus for the cytoplasm through a nuclear pore, and heads for a ribosome to make proteins. 133. How are genes related to protein synthesis? Genes are simply sections of DNA that code for specific proteins. Many proteins are enzymes, which catalyze and regulate chemical reactions. Proteins are each specifically designed to build or operate a component of a living cell.

20. End Show Slide 20 of 39 Copyright Pearson Prentice Hall The cell uses the ___ instructions to create RNA (mRNA). mRNA leaves the nucleus for the cytoplasm through a nuclear pore, and heads for a ______ to make proteins. How are genes related to protein synthesis?

21. End Show Slide 21 of 39 Copyright Pearson Prentice Hall 12–3 The role of a master plan in a building is similar to the role of which molecule? a.messenger RNA b.DNA c.transfer RNA d.ribosomal RNA

22. End Show Slide 22 of 39 Copyright Pearson Prentice Hall 12–3 A base that is present in RNA but NOT in DNA is a.thymine. b.uracil. c.cytosine. d.adenine.

23. End Show Slide 23 of 39 Copyright Pearson Prentice Hall 12–3 The nucleic acid responsible for bringing individual amino acids to the ribosome is a.transfer RNA. b.DNA. c.messenger RNA. d.ribosomal RNA.

24. End Show Slide 24 of 39 Copyright Pearson Prentice Hall 12–3 A region of a DNA molecule that indicates to an enzyme where to bind to make RNA is the a.intron. b.exon. c.promoter. d.codon.

25. End Show Slide 25 of 39 Copyright Pearson Prentice Hall 12–3 A codon typically carries sufficient information to specify a(an) a.single base pair in RNA. b.single amino acid. c.entire protein. d.single base pair in DNA.