If the sequence of a codon on the mRNA is 59-AUG-39, what will the sequence of the anticodon be? Remember that the hydrogen bonding rules require antiparallel strands. It is easiest to write the anticodon first 3−9 −−−→ 59 and then reverse it to the 5−9− −−→ 39 order.
> Write a chemical equation for the transfer of an amino group from alanine to a-ketoglutarate, catalyzed by a transaminase.
> At which steps in the citric acid cycle do oxidation reduction reactions occur?
> What does the term aerobic respiration mean?
> What is the cellular location of the electron transport systems?
> What is the name of the enzyme that catalyzes ATP synthesis in mitochondria?
> How many molecules of ATP are produced when one molecule of FADH2 is oxidized by oxidative phosphorylation?
> What is the terminal electron acceptor in aerobic respiration?
> Tire pressure is measured in units of lb/in2. Convert 32 lb/in2 to g/cm2 (use the proper number of significant figures).
> What molecules serve as signals to decrease the rate of the reactions of the citric acid cycle?
> If the muscle of an organism had no lactate dehydrogenase, could anaerobic glycolysis occur in those muscle cells? Explain your answer.
> Which of the four allosteric enzymes or enzyme complexes in the citric acid cycle are under negative allosteric control? Which are under positive allosteric control?
> An essential gene has the codon 59-UUA-39 in a critical position. If this codon is mutated to the sequence 59-UUG- 39, what is the expected consequence for the cell?
> Define the term effector.
> What happens to the reading frame of a gene if a nucleotide is deleted?
> What is the major role of coenzyme A in catabolic reactions?
> Write the equation for the reaction catalyzed by glyceraldehyde-3-phosphate dehydrogenase. Highlight the chemical changes that show this to be an oxidation reaction.
> In the oxidation of succinate to fumarate, what is the structural evidence that an oxidation reaction has occurred? What functional groups are involved?
> To which family of organic molecules do a and d belong? To which family of organic molecules do b and c belong? (а) (b) CH,OH С-Н Н-С-ОН НО-С—Н НО-С—Н Н-С—ОН H--OH Н-С-ОН Н-С—ОН H-C-H H-Ć-H "0-P-O -O-P-O- (с) CH,OH (d) C=O C-H H-C-H Н-С—ОН H-C-H -0
> Describe transmembrane proteins and list some of their functions.
> Describe exercise intolerance and the cause of the condition.
> What is the chemical meaning of the term decarboxylation? Give an example of a decarboxylase.
> How many molecules of FAD are converted to FADH2 during one turn of the citric acid cycle?
> Are the following statements true or false? If false, rewrite the statements to make them accurate. Glycolysis and the citric acid cycle are aerobic processes. These anabolic processes occur in the mitochondria and the cytoplasm, respectively.
> What is the function of the promoter sequence in the process of transcription?
> Why must the NADH produced in glycolysis be reoxidized to NAD1?
> Write the equation for the conversion of isocitrate to a-ketoglutarate, and circle the chemical change that reveals the type of reaction that is occurring.
> Draw a diagram illustrating semiconservative DNA replication.
> Write a chemical equation for the production of acetyl CoA from pyruvate. Under what conditions does this reaction occur?
> In the reaction catalyzed by pyruvate dehydrogenase, pyruvate is also oxidized. What substance is reduced when pyruvate is oxidized? What is the product of that reduction reaction?
> B(OH)3 has an incomplete octet around the boron atom. Draw the Lewis structure of B(OH)3.
> Compare and contrast anabolism and catabolism in terms of their roles in metabolism and their relationship to ATP.
> What kinds of proteins are found in the inner mitochondrial membrane?
> What biochemical processes occur in the matrix space of the mitochondria?
> How do the mitochondria differ from the other components of eukaryotic cells?
> Define the term cristae.
> What is the function of an anaplerotic reaction?
> Where do the reactions of the urea cycle occur?
> What is the function of a transaminase?
> Write a balanced chemical equation for the reduction of FAD.
> Draw the structure of UDP-glucose and describe its role in glycogen synthesis.
> Consider two beakers, one containing a mixture of NaOH and NaCl (each solute is 0.10 M) and the other containing a mixture of NH3 and NH4Cl (each solute is also 0.10 M). If we add 0.10 M HNO3 (10.0 mL) to each beaker, which solution will have the greater
> Describe the function of the debranching enzyme in glycogen degradation.
> What defects of glycogen metabolism would lead to a large increase in the concentration of liver glycogen?
> a. What enzyme in glycogen metabolism is stimulated by glucagon? b. What effect does this have on glycogen metabolism?
> What does the term hyperglycemia mean?
> Why must the blood glucose level be carefully regulated?
> What is a cloning vector?
> l-Alanine can be converted to pyruvate. Can l-alanine also be converted to glucose? Explain your answer.
> a. What causes the genetic disease xeroderma pigmentosum? b. Why are people who suffer from xeroderma pigmentosum prone to cancer?
> What is the role of guanosine triphosphate in gluconeogenesis?
> Use the periodic table and determine the shorthand electron configuration of each of the following atoms. a. I b. Al c. V
> Of what value is the NADPH that is produced in the pentose phosphate pathway?
> A family started a batch of wine by adding yeast to grape juice and placing the mixture in a sealed bottle. Two weeks later, the bottle exploded. What metabolic reactions—and specifically, what product of those reactions—caused the bottle to explode?
> What enzymes catalyze the conversion of pyruvate to ethanol and carbon dioxide?
> Explain the value of alcohol fermentation in bread making.
> Write a balanced chemical equation for the conversion of pyruvate to lactate.
> What molecule serves as an allosteric inhibitor of hexokinase?
> What are the major products of glycolysis?
> What features do the reactions catalyzed by hexokinase and phosphofructokinase share in common?
> Draw the intermediate that would be formed in each of these reactions. (а) (b) CH,OH С-Н Н-С-ОН НО-С—Н НО-С—Н Н-С—ОН H--OH Н-С-ОН Н-С—ОН H-C-H H-Ć-H "0-P-O -O-P-O- (с) CH,OH (d) C=O C-H H-C-H Н-С—ОН H-C-H -0-P-0- -O-P-O-
> Why are red blood cells particularly susceptible to a deficiency of an enzyme in the glycolysis pathway?
> How does the presence of the insulin receptor on the surface of a cell identify that cell as a target cell?
> Match each of the following enzymes with the appropriate class of enzymes that it represents. (Hint: An enzyme classification may be used more than once or not at all.) a. Phosphoglucose isomerase b. Phosphofructokinase c. Triose phosphate isomerase d
> Write a chemical equation for the transfer of a phosphoryl group from ATP to fructose-6-phosphate.
> Where in the muscle cell does glycolysis occur?
> How many molecules of ATP are produced by substrate level phosphorylation during glycolysis?
> What are the end products of glycolysis?
> How are amino acids transported into the cell?
> How are fatty acids taken up into the cell?
> Write an equation showing the hydrolysis of sucrose.
> What is a hydrolysis reaction?
> What is meant by the term high-energy bond?
> All of the following Lewis structures are incorrect. Find the errors and write the correct structures. а. с. H :F: H-C=0=H :F-S - F H. :F: b. :0: Н-с—Н
> Describe the structure of ATP.
> Referring to the structures in Figures 20.1 and 20.3, draw the structures for nucleotides consisting of the following units. Figures 20.1: Figures 20.3: a. 29-Deoxyribose, thymine, one phosphoryl group b. Ribose, cytosine, three phosphoryl groups c.
> How does insulin affect the storage and degradation of glycogen?
> Describe the reaction catalyzed by the branching enzyme.
> What components of nucleic acids are heterocyclic amines?
> What do the three irreversible reactions of glycolysis have in common?
> Write a “word” equation showing the reaction catalyzed by glycogen synthase.
> What is the function of the ribosomal A-site in protein synthesis?
> What structural features of trypsin, chymotrypsin, and elastase account for their different specificities?
> Draw a DNA sequencing gel that would represent the sequence shown below. Be sure to label which lanes of the gel represent each of the four dideoxynucleotides in the chain termination reaction mixture. 59-GACTATCCTAG- 39
> What is meant by the term chromosome walking?
> How does a dideoxynucleotide cause chain termination in DNA replication?
> Where are the proteolytic enzymes pepsin and trypsin formed? Where do they carry out their function?
> What are the potential benefits of the information gained in the Human Genome Project?
> How is the polymerase chain reaction applied in forensic science?
> A wax found in the head of sperm whales is cetyl palmitate. What fatty acid and what alcohol are used to form this compound?
> Explain why UV lights are effective germicides on environmental surfaces.
> What is an allosteric enzyme?
> What are deletion and insertion mutations?
> Draw the structure of an alanine residue bound to the 39 position of adenine at the 39 end of alanyl tRNA. The amino acyl linkage is formed between the 39—OH of the tRNA and the carboxylate group of the amino acid methionine. АТР
> What peptide sequence would be formed from the mRNA. 59-AUGUGUAGUGACCAACCGAUUUCACUGUGA-39?
> Draw the Lewis structure of HS-.
> Why must pyruvate be used and NADH be reoxidized so that glycolysis can continue?
> Why does an enzyme lose activity when the pH is drastically changed from optimum pH?
> What are the two tRNA binding sites on the ribosome?
> Which amino acids are encoded by six codons?
> Why is the genetic code said to be mutation-resistant?
