Week_6a_Proteins_and_Translation_S23

Name _____________________________________________ Proteins & Translation Pre-Class Worksheet Fill out this worksheet as you complete your pre-class assignments (Chapter 5 – Introduction & Sections 5.1-5.2). Bring your completed worksheet to class to use as a reference for in-class activities. After completing your pre-class assignments, you should be able to: • Discuss the four levels of protein structure and relate them to the function of a protein. • Define the “denatured” as it relates to protein structure. • Compare and contrast translation in prokaryotes and eukaryotes. • Describe the structure and function of the ribosome. • Explain the major events that occur during initiation, elongation, and termination of translation. • Discuss the role of tRNA in the process of translation. 1. As you read about protein structure and build your paper model of the green fluorescent protein GFP, describe each of the four levels of protein structure below (GFP model: https://cdn.rcsb.org/pdb101/learn/resources/gfp-model.pdf ). Try to use these terms into your descriptions: peptide bond, alpha-helix, beta-sheet, hydrogen bond, covalent bond. a. Primary b. Secondary c. Tertiary d. Quaternary 2. What happens to a protein if it becomes denatured? 3. Complete the following sentences: a. A codon is made up of ______ (number) of nucleotides and is found in _____________ (type of molecule). b. An anticodon is made up of ______ (number) of nucleotides and is found in _____________ (type of molecule). 4. The diagram below represents a eukaryotic mRNA molecule. Label on the diagram where you would expect to find the start codon and stop codon. You may find it helpful to refer to figure 5.20 in the textbook. trisha Narurran sequence of amino acid in a polypeptide chain folded primary chain that occur because of interaction within the backbone three dimensional structure of a polypeptide that is also due to interaction within the protein hydrophobic amino acids group together on the inside of the structure while the hydrophilic groups are on the outside interacting wt water some proteins have a quaternary structure that occurs when subunitt come together A protein is denatured when the interactions within the protein are disrupted changing the quarter navy tertiary and secondary structures and rendering the protein in tap able 3 MRNA 3 tRNA start codon stop codon

5. The diagram at right represents a ribosome bound to mRNA. a. On the diagram label the following features of the ribosome: small subunit, large subunit, aminoacyl (A) site, peptidyl (P) site, exit (E) site. b. What is the ribosome made out of? 6. Explain the major events that occur during initiation, elongation, and termination of translation a. Initiation b. Elongation c. Termination 7. Refer to Figure 5.15 in the textbook. The sequence at right represents a single codon in a molecule of mRNA. a. Write the complementary tRNA sequence that will base pair with this codon. Be sure to label the 5’ and 3’ ends. b. What amino acid do you think will be attached to the tRNA molecule that has the anticodon that you drew above? In addition to Figure 5.15, you may find it helpful to refer to the codon table in Table 5.1 in the textbook. 8. The diagram below represents a ribosome that is in the middle of the elongation phase of translation. Using Figure 5.18 as a guide, draw a picture of what the same ribosome will look like when the next tRNA has entered the A site. 9. Compare and contrast the fate of the process of translation in prokaryotes and eukaryotes. How is the process similar? How is it different? Try to u se the terms “5’ cap” and “polycistronic mRNA” in your explanation. 5’ – GUA – 3’ peptidyl P large life site amino subunit Gg A sushi RNA protein the ribosome combined with the mRNA the first tRNA molecule so translation can start RNAS bring amino acids to the ribosome and the amino acids are linked together The finished polypeptide chain is released a 3 CAU S b Val V Met phe th Aia v o I C ou A v o u v u a co o ca o c o g 3 Both processes synthesize proteins by decoding mRNA Prokaryotic translation occurs synchronously with transcription but eukaryotic translation occur at different times Eukaryotic mRNA is in the nucleus but prokaryotic mRNA olives in the cytoplasm Eukaryotes are slower at translation as well A 5 lap is added to the prokaryotic transcript that allows trans tription translation to other simultaneously