Biological Science (6th Edition)
6th Edition
ISBN: 9780321976499
Author: Scott Freeman, Kim Quillin, Lizabeth Allison, Michael Black, Emily Taylor, Greg Podgorski, Jeff Carmichael
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 8, Problem 14PIAT
The catalytic activity of PAH also requires a coenzyme that is oxidized in the reaction. This coenzyme is then subsequently reduced by NADH to regenerate it for additional PAH reactions. If a person were diagnosed with a novel form of PKU, in which the PAH enzyme was fully functional, what defects would you look for to explain the accumulation of phenylalanine?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Hexokinase catalyzes the first step of glycolysis, in which glucose is phosphorylated to form glucose‑6‑phosphate. Give two reasons why a Mg2+ cation is required to facilitate this reaction.
In Bacillus subtilis, threonine is metabolized by the following sequence of reactions: (a) oxidation; (b) decarboxylation;(c) transamination; and (d) oxidation to produce pyruvate. Outline this sequence of steps, show the structures of thesubstances, use abbreviations for the cofactors, and show any enzyme-bound coenzymes.
What type of enzyme bound intermediate is likely for reaction (d)?
Explain why, glucose-6-phosphate will prefer to go via the pentose phosphate route. What additional chemical is created by this route, and what role does it play in anabolic pathways?
Chapter 8 Solutions
Biological Science (6th Edition)
Ch. 8 - 1. If a reaction is exergonic, then which of these...Ch. 8 - 2. What is a transition state?
a. the shape...Ch. 8 - 3. How does pH affect enzyme-catalyzed...Ch. 8 - Explain how feedback inhibition regulates...Ch. 8 - 5. Explain the lock-and-key model of enzyme...Ch. 8 - If you were to expose glucose to oxygen on your...Ch. 8 - Prob. 7TYUCh. 8 - Using what you have learned about changes in Gibbs...Ch. 8 - MODEL Draw a chemical equation to represent the...Ch. 8 - Prob. 10TYPSS
Ch. 8 - Prob. 11PIATCh. 8 - 12. MODEL The first reaction in the catabolism of...Ch. 8 - 13. PROCESS OF SCIENCE Protein structure is often...Ch. 8 - 14. The catalytic activity of PAH also requires a...Ch. 8 - 15. The functional form of PAH contains four...Ch. 8 - 16. SOCIETY Starting in the 1960s, newborns that...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.Similar questions
- When the enzyme is incubated with oxaloacetate, will oxaloacetate be observed?arrow_forwardExplain the basis for the following statement: As a coenzyme, pyridoxal phosphate is covalently bound to enzymes with which it functions; yet during catalysis the coenzyme is not covalently bound.arrow_forwardUDP-glucuronosyltransferase enzymes bind the organic compound UDP-glucuronic acid (UDP-GA) in order to catalyse the transfer of a glucuronic acid group from UDP-GA to a drug molecule, releasing UDP from the active site as a product. UDP is then regenerated by the activity of another enzyme. What terms could be used to describe UDP-GA?arrow_forward
- Are any of the intermediates in the β-oxidation pathway chiral? Explain.arrow_forwardGlyphosate, which inhibits the EPSP synthase reaction of the shikimic acid pathway, is a phosphonic acid derivative of glycine; hence its name (glycine phosphonate). Based upon your knowledge of the EPSP synthase reaction (see pages 908–909), would you expect the inhibition to be competitive or noncompetitive with respect to each of the substrates? Briefly explain your answer.arrow_forwardThe immediate precursor to acetyl–CoA from glycolysis is pyruvate.a) Write the pathway (not the mechanism) for the series of steps for this conversion. Includestructures for all coenzymes and reactants for each step.b) Discuss the mechanistic advantages offered by this multienzyme complex. Be specific and giveexamples.c) The last step of the reaction, catalyzed by enzyme 3, includes three coenzymes and oxidation.Write the mechanism for this enzyme.arrow_forward
- Put these steps in the mechanism of chymotrypsin catalysis in order from first to last. Note that some references may not break out each of these steps individually, but all steps should be ordered. There will be eight steps.arrow_forwardCopper is a cofactor in several enzymes, including lysyl oxidase and superoxide dismutase.Ceruloplasmin, a deep-blue glycoprotein, is the principal copper-containing protein in blood. It isused to transport Cu2+ and maintain appropriate levels of Cu2+ in the body’s tissues.Ceruloplasmin also catalyzes the oxidation of Fe2+ to Fe3+, an important reaction in ironmetabolism. Because the metal is widely found in foods, copper deficiency is rare in humans.Deficiency symptoms include anemia, leukopenia (reduction in blood levels of white blood cells),bone defects, and weakened arterial walls. The body is partially protected from exposure toexcessive copper (and several other metals) by metallothionein, a small, metal-binding protein thatpossesses a large proportion of cysteine residues. Certain metals (most notably zinc and cadmium)induce the synthesis of metallothionein in the intestine and liver.In Menkes syndrome intestinal absorption of copper is defective. How can affected infants…arrow_forwardThere is another class of aldolase enzymes known as Class II. These enzymes are found in fungi, algae, and some bacteria. This class differs for Class I in that these enzymes do not have a Lys residue associated with their active sites, but contain a divalent cation (usually Zn2+ or Fe2+) in the active site. Outline a possible mechanism for a Class II aldolase and explain the function of the metal ion in the reaction.arrow_forward
- Some bacteria use the citric acid cycle intermediate, a-ketoglutarate, plus acetyl-CoA, as the starting point for lysine biosynthesis. The first part of this biosynthetic pathway uses the same chemical strategy found in the citric acid cycle. Propose a four-step pathway for the conversion of a-ketoglutarate to 2-oxoadipate. Draw the three missing intermediates, and indicate the chemistry involved in each reaction. Include any cofactors that you think might be required for specific steps.arrow_forwardDuring glycogen synthesis, glucose-1P is converted into a molecule called UDPG. This reaction also cleaves uridine triphosphate (UTP) forming uridine monophosphate and pyrophosphate (PPi). Provide four reasons why UTP can be used to power this reaction (no diagrams necessary).arrow_forwarda-Ketoglutarate plays a central role in the biosynthesis of several amino acids. Arrange the reactions to outline the net synthesis of a-ketoglutarate from pyruvate. Your proposed sequence must not include reactions that result in the net consumption of other citric acid cycle intermediates. Pyruvate + ATP + CO, + H,0 → oxaloacetate + ADP + P; + H+ a-Ketoglutarate + CoA + NAD+ → succinyl-CoA + CO,+NADH + H+ Pyruvate + CoA + NAD+ acetyl-CoA + CO,+NADH + H+ Oxaloacetate + acetyl-CoA → citrate + CoA Oxaloacetate + NADH + H+ malate + NAD+ Citrate → isocitrate Isocitrate + NAD+ a-ketoglutarate + CO,+NADH + H* 2.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
BiochemistryBiochemistryISBN:9781305577206Author:Reginald H. Garrett, Charles M. GrishamPublisher:Cengage Learning
Biochemistry
Biochemistry
ISBN:9781305577206
Author:Reginald H. Garrett, Charles M. Grisham
Publisher:Cengage Learning
Mitochondrial mutations; Author: Useful Genetics;https://www.youtube.com/watch?v=GvgXe-3RJeU;License: CC-BY