Under what conditions might one expect a deficiency of hypoxan- thine-guanine phosphoribosyltransferase to affect the rate of pyrimidine nucleotide biosynthesis? How might one estimate the rate of pyrimidine nucleotide biosynthesis in living animals or people?
Q: Orotic aciduria is a rare hereditary disorder due to deficient orotate phosphoribosyltransferase and…
A: Introduction Orotic aciduria is a pyrimidine metabolism error and an autosomal recessive disorder…
Q: List the two components of the active Telomerase holoenzyme.
A: The ribonucleoprotein that is responsible for the synthesis of telomeric repeat sequence is called…
Q: If this molecule can inhibit toxic effects at 0.5mM against gastric carcinoma cells, does it mean…
A: IC50 is the concentration at which 50% inhibitory effect is observed.
Q: Draw in detail the pathway of de novo synthesis of deoxythymidine phosphate and provide a brief…
A: First carbamoyl phosphate is synthesized , which then enters the de-novo synthesis pathway for…
Q: Each of the hydroxyl groups of glucose can be methylated with reagents such as dimethyl sulfate…
A: Glucose is the primary energy source in the body. It is stored as a storage polymer, glycogen.…
Q: Bacterial species that are capable of synthesising the amino acid histidine do not need it in their…
A: Introduction Histidine is synthesized from phosphoribosyl pyrophosphate (PRPP), which is made from…
Q: How many of these strains of E. coli would have no ß-galactosidase activity?
A: Grouping functionally relevant genes together is a method used by bacteria to manage gene…
Q: .Propose a mechanism for the conversion of 5- formamidoimidazole-4- carboxamide ribonucleotide into…
A: Purine is nucleic acids that are formed by the fusion of the pyrimidine ring with the imidazole ring…
Q: Define multiubiquitinylation.
A: In the cell, proteins are degraded or modified with the help of the ubiquitin pathway. In the cell,…
Q: 6-Diazo-5-oxonorleucine (DON) irreversibly inhibits glutamine-dependent amidotransferases. CH=N+=N-…
A: Introduction: DON is a water-soluble glutamine enemy which was separated initially from Streptomyces…
Q: What is the primary and secondary structure of ubiquitin-conjugating enzyme?
A: Ubiquitin is a 76 amino acid polypeptide that is found in a eukaryotic cell. ubiquitin is served…
Q: What advantages are there for synthesizing an inactive protein that must subsequently be activated…
A: When the proteins are synthesized into naive polypeptide then these are transferred to the…
Q: 12. RNase A is a ribonuclease enzyme that degrades single stranded RNA. There are three key amino…
A: RNaseA catalysis is a typical example of acid base catalysis. Histidine is a common amino acid in…
Q: From the result shown, what might be the histidine biosynthetic pathway (the order of enzymes)?
A: Histidine biosynthesis is an ancient metabolic partway present in bacteria, archaea, lower…
Q: The enzyme chymotrypsin, catalyses the hydrolysis of nitrophenyl acetate and pther acyl esters. Name…
A: Chymotrypsin is a digestive enzyme belonging to a super family of enzymes called serine proteases.…
Q: Which of the following regulatory mechanisms will specifically inhibit pyrimidine synthesis (and not…
A: De novo pathway and salvage pathways are two pathways used for nucleotide biosynthesis. In the…
Q: . Mutants of Neurospora crassa that lack carbamoyl phosphate syn- thetase I (CPS I) require arginine…
A: The process of carbamoyl phosphate synthetase I (CPS I) occurs in the mitochondria as the enzyme is…
Q: After being stabilized with supplemental oxygen, a blood transfusion, and medication to help with…
A: Hydroxyurea: It is a class of antimetabolites. This class of drug is used to treat cancer. It is a…
Q: Mutants of Neurospora crassa that lack carbamoyl phosphate synthetase I (CPS I) require arginine in…
A: Carbamoyl Phosphate : It is an anion of biochemical significance. In land-dwelling animals, it is an…
Q: Why doesn’t polynucleotide phosphorylase (Ochoa’s enzyme) synthesize RNA in vivo?
A: Ribonucleic acid (RNA) is the first discovered inheritable material. Severo Ochoa discovered the…
Q: What is an important difference between the biosynthesisof purine nucleotides and that of pyrimidine…
A: Introduction: A nucleoside and a phosphate make up nucleotides, which are organic molecules. They…
Q: Why is ti advantageous for a cell to expend metabolic energy to polymerize gulucose molecule.?
A: Human blood possesses sugar in the form of glucose, it is being carried to all cells as a source of…
Q: What are the low-molecular-weight precursors needed for the de novo biosynthesis of the purine ring,…
A: Purine nucleotides are synthesized in the body via de novo synthesis or salvage pathway. Adenine and…
Q: the structures of chymotrypsin and other serine proteases revealed that the active sites of these…
A: Chymotrypsin and trypsin are examples of serine proteases. Chymotrypsin cleaves the peptides of…
Q: 14C-Labeled glyceraldehyde 3-phosphate was added to a yeast extract. After a short time, fructose…
A: Glyceraldehyde 3-phosphate (G3P) is also known as triose phosphate or 3-phosphoglyceraldehyde. It is…
Q: In the serine protease triad, the proximity of an aspartate carboxylate group of histidine raises…
A: Serine protease is a class of proteolytic enzymes in which serine residue is present at the active…
Q: What cofactors are necessary for methyltransferases t Homocysteine Methionine o work?
A: Methyltransferases are primarily responsible for the transfer of methyl groups to other molecules.
Q: Mutations in the Galactose-1-Phosphate Uridyl Transferase Gene Can you use RFLP to identify this…
A: Mutation --It is an alteration in the sequence of nucleotides in a genome of an organism , virus…
Q: comparing the synthesis of pyrimidines vs. purines
A: The purines and pyrimidines are the two families of nitrogenous bases , which are make up nucleic…
Q: Why is carboxyl terminal domain (CTD) phosphorylation functionally important?
A: Transcription is the molecular mechanism in which the information in DNA is transcribed into the…
Q: The text states that in E. coli ribonucleotide reductase Tyrosine-122 was identified as the source…
A: Ribonucleotide reductase (RNR) is a key enzyme that mediates the synthesis of deoxyribonucleotides,…
Q: The structure of adenylate cyclase is similar to the structures of some types of DNA polymerases,…
A: adenylate cyclase DNA polymerases Convert ATP to cAMP Adds dNTP to DNA Plays role in signal…
Q: Phosphoribosyltransferase (PRT) catalyzes the attachment of a salvaged purine nitrogenous base on…
A: In salvage pathway, PRPP is used as a source of the ribose 5-phosphate group.
Q: What is the function of a novel metagenomic alpha/beta-fold esterase? And how does its structures…
A: The alpha/beta-hydrolase fold family of enzymes is quickly establishing a reputation as one of the…
Q: Why do E. coli cells with a defective lacZ gene fail to show galactoside permease activity after the…
A: Galactoside permease also known as Beta-galactoside permease is a protein which is encoded by lacY…
Q: Since mammalian DNA contains roughly 25% thymine residues, why do mammalian cells need a thymine-DNA…
A: Introduction: DNA is the type of nucleic acid that is present in the nucleus of the cell. It is the…
Q: Please describe the enzyme - mediated reactions required for a histidine, freely floating in the…
A: Histidine is a amino acid which is used in protein biosynthesis. The biosynthesis of histidine…
Q: Why Phenylmethylsulfonyl fluoride (PMSF, shown in Fig.) does not inhibit aspartate protease as…
A: The chemical compounds which are used to protect the proteins from the digestive function of the…
Q: In studies of the amino acid sequence of wild-type and mutant forms of tryptophan synthetase in E.…
A: The nitrogenous bases that form the mRNA chain are Adenine (A), Guanine (G), Cytosine (C), and…
Q: The natural sulfur cycle involves many sulfur- reducing and sulfur-oxidizing bacteria. For example,…
A: Sulphur cycle describes the flow of Sulfur from inorganic component to organic component of the…
Q: List all the enzymes of nucleotide biosynthesis that use glutamine as an amino group donor.
A: Introduction- Nucleotide plays an important role in many biological systems as biosynthesis of…
Step by step
Solved in 2 steps
- What would be the effect on the activity of phosphofructokinase of the mutation of Asp103 to the unusual amino acid shown below? Explain in terms of actual structures of the side chains of Asp and this unusual amino acid.The objective is to study a novel protease P isolated from the digestive tract of an Amazonian insect. This protease can exist into two forms Pi and Pa which have identical amino acid sequences (both of 80 kDa). However, only Pa shows proteolytic activity. To better understand the activation mode of Pi (inactive form) in Pa (active form), the following experiment was done using DIPF. DIPF (diisopropylphosphofluoridate) is a well-known irreversible inhibitor of serine proteases. It reacts with the catalytic serine residue of the active site of proteases as shown below: Enzyme -CH₂OH + CH(CH3)2 O F-P=0 O CH(CH3)2 Diisopropylphospho- fluoridate (DIPF) Enzyme -CH,—O CH(CH3)2 O <=0 O CH(CH3)2 DIP-Enzyme Both proteases Pa and P₁ were incubated with 32P-DIPF for 30 min at 37°C, and then dialysed to remove excess of unreacted radiolabelled reagent. The two proteases were then analyzed in Sodium Dodecyl Sulphate-Polyacrylamide Gel Electrophoresis (SDS-PAGE), with and without 2-mercaptoethanol.…Wild-type E. coli cells can synthesize all 20 common amino acids, but some mutants, called amino acid auxotrophs, are unable to synthesize a specific amino acid and require its addition to the culture medium for optimal growth. Besides their role in protein synthesis, some amino acids are also precursors for other nitrogenous cell products. Consider the three amino acid auxotrophs that are unable to synthesize glycine, glutamine, and aspartate, respectively. Match each nitrogenous product with the mutant or mutants that would fail to synthesize it. Each mutant may fail to synthesize more than one nitrogenous product, and some nitrogenous products may fail to be synthesized by more than one mutant. glycine auxotrophs glutamine auxotrophs aspartate auxotrophs Answer Bank adenine nucleotides cytosine nucleotides guanine nucleotides uridine nucleotides
- Can you please order the following steps involving the regeneration of ribonucleotide reductase that occurs in most animals so that it may carry out the formation of deoxyribonucleotides. (Note that not all steps are shown.) 1. Reduction of thioredoxin 2. Reduction of ribonucleotide reductase 3. Oxidation of thioredoxin reductase 4. Reduction of thioredoxin reductaseWhy is the position of Cys 58 important in 3GRS(GLUTATHIONE REDUCTASE)? When Cys 58 is mutated to GLY 58 how would it impact the 3D structure and function of 3GRS? explain in terms of how Cys and GLY have different properties and how it would impact the function of 3GRS (the binding sites etc.) You can see your structure(3GRS ) here or any other website: https://www.rcsb.orgWhy Phenylmethylsulfonyl fluoride (PMSF, shown in Fig.) does not inhibit aspartate protease as potent as serine protease?
- Certain glutamine analogs irreversibly inactivate enzymes that bind glutamine. Identify the nucleotide biosynthetic intermediates that accumulate in the presence of those compounds.Orotic aciduria is a rare hereditary disorder due to deficient orotate phosphoribosyltransferase and orotidine-5'-decarboxylase activities that are encoded by Uridylate (UMP) synthetase gene in de novo pyrimidine biosynthesis. The characteristic of this disorder is excessive excretion of orotic acid in urine. A mutation of UMP synthetase gene has been identified as R96G (at amino acid position 96, Arginine is changed to Glycine). In orotic aciduria, predict the consequences of deficient UMP synthetase by identifying which downstream enzyme missing its action. One of important molecules to be derived from pyrimidine biosynthesis is deoxycytidine triphosphate (dCTP) for DNA replication and repair. How is dCTP synthesized, include what enzymes and important intermediates in the pathway? 3. As thymidine triphosphate (dTTP) is needed for DNA replication and repair, what enzymes and intermediates are required to get dTTPThe majority of bacterial mutations that need isoleucine also require valine for growth. Why? Which enzyme or process would be deficient in a mutant that requires solely isoleucine for growth (rather than valine)?
- Which of the following statements regarding Anfinsen's denaturing experiments with ribonuclease A are valid? (i) Exposing the denatured protein to air oxidation and then dialysis to remove urea restored the protein to its original functionality. (ii) Removing urea by dialysis and then allowing air oxidation of the denatured protein restored the protein to its original functionality. (iii) Denaturing the protein with both urea and β-mercaptoethanol yielded an inactive protein. (iv) Protein folding is determined by its primary sequence.3) Histone deacetylases (HDACs) are zinc-dependent enzymes that catalyse the conversion of acetyllysine to lysine. e) HN a) Propose the mechanism for the HDAC-catalysed reaction. b) What is the role of zinc ion in HDAC catalysis? c) d) f) HDAC NH₂ Draw the pH-activity profile for HDAC-catalysed conversion of acetyllysine to lysine. Explain. Suggest two acetyllysine analogues that are substrates for HDACs. One should be a better substrate than acetyllysine, whereas the other one should be a worse substrate than acetyllysine. Explain. Mutations in the HDAC sequence could lead to a loss of the catalytic function. Which mutations are problematic? Lysine acetylation is a reversible reaction using acetyl-CoA as a co-substrate. Which coenzymes are required for synthesis of acetyl-CoA in nature? Propose the mechanism.In the case of normal RNase A, Anfisen found that oxidizing the Cys residues before slowly removing the urea gave a very different result than oxidizing the Cys after slowly removing the urea. When the urea was removed first, Anfisen recovered 100% of the catalytic activity. When the urea was removed after oxidation, only about 1% of the activity (1/105) was recovered. The conclusion was that 104 of every 105 molecules was misfolded, and therefore catalytically inactive. Let's say someone raises an objection to this interpretation, and says that perhaps, instead, something chemically happens to the active site of RNase A when it is oxidized before refolding, and that the ~1% activity measured represents the residual and greatly reduced enzyme activity of all of the molecules, and the number is just coincidently similar to 1/105. (In other words, instead of 104 completely inactive molecules for every 1 completely active molecule, all molecules are equally damaged, and only function at…