Unit3 - Unit 3 1 UNIT 3 PART A: MYOGLOBIN PART B:...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Unit 3 1 U NIT 3 P ART A: M YOGLOBIN P ART B: H EMOGLOBIN P ART C: I NTRODUCTION TO E NZYMES P ART D: E NZYME K INETICS P ART A: M YOGLOBIN Assignment: Nelson & Cox, pp. 157 - 162 (stop at "Oxygen is transported in the blood by hemoglobin"; skim pp. 160 - 161). Hemoglobin and myoglobin play vital roles in one of the most important aspects of animal metabolism - the utilization of oxygen. The most efficient energy - generating mechanisms in animal cells require molecular oxygen. Proteins that deliver oxygen to cells, and store it, until needed, are essential. Oxygen delivery is carefully regulated to meet the demands of tissues. Studies on oxygen transporting proteins have provided vast insight into the function and regulation of proteins. Myoglobin stores and transports oxygen in vertebrate muscle tissue. The atomic structure of myoglobin was determined by x-ray crystallography in the 1950's. Because of the wealth of information on myoglobin it has become a classic example of protein structure and function.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Unit 3 2 1. Discuss the following terms: (pp. 157 - 158) a. Ligand b. Binding site c. Induced Fit d. Substrate e. Catalytic (active) site 2. Some important features of myoglobin: a. Why do multicellular organisms transport oxygen on Fe +2 incorporated into a heme group (p. 158)? b. Discuss the role of the heme group (Fig 5-1, p. 159) 1) Identify the pyrrole ring 2) Point out the six coordination points to iron 3) Discuss the oxidation state of iron in myoglobin (and hemoglobin) c. What is a "globin" (p. 159)? Use Fig. 5-3 (p. 160) to describe the secondary and tertiary structure of myoglobin. Describe the location of the heme group in the protein. d. Describe the polar or non-polar character of the inside and outside of the native protein. e. What is the physiological role of myoglobin? 3. Based on what you learned in Unit 2, review how myoglobin folding occurs.
Background image of page 2
Unit 3 3 4. The oxygen binding site in myoglobin involves the heme group and two histidine residues. Is it surprising to find histidine residues in the interior of a protein? Explain. 5. Use Fig. 5-4 (p. 161) to discuss the oxygen binding behavior of myoglobin. a. What is the meaning of P 50 ? b. What is the P 50 of oxygen binding to myoglobin? c. What does the hyperbolic shape of the binding curve tell you about the sensitivity of myoglobin to changes in ligand concentration (p. 163)? 6. Protein structure affects how ligands bind a. Use Fig 5-5 (p. 162) to discuss the role of the distal histidine in the myoglobin ligand binding site. b. Discuss the role of the globin protein in preventing heme iron oxidation (p. 158). c. What is "molecular breathing" and why is it important in terms of myoglobin's function (p. 162)? P
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 13

Unit3 - Unit 3 1 UNIT 3 PART A: MYOGLOBIN PART B:...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online