
Concept explainers
To determine: The positions in the purine ring of a purine
Introduction:
There are two types of nitrogenous bases: purines and pyrimidines. Adenine and guanine are the purine bases with double ring structures. Cytosine and thymine are the pyrimidines bases that have single ring structure. These bases pair with their complementary bases and form a nucleotide sequence through hydrogen bonding.

Explanation of Solution
Explanation:
Adenine is linked to thymine with double hydrogen bond and guanine is linked to cytosine with triple hydrogen bond. The two nucleotides are joined together by the phosphodiester bond.
Purine is a structure that contains nine member ring which is made up of a imidazole ring along with a pyrimidine ring. In adenine amino group present at the sixth position along with first position’s nitrogen is involved in Watson-Crick base pairing with complementary pyrimidine base which is thymine.
In guanine, nitrogen present at first position and amino group at second carbon along with oxo group at sixth carbon is involved in Watson-Crick base pairing with complementary pyrimidine base which is cytosine.
Thus, the positions of purine ring that have the property to form hydrogen bonds but do not participate in Watson-Crick base pairing are the nitrogen which is present at third and seventh position of purine ring.
Conclusion:
Third and seventh positions in purine ring are involved in hydrogen bonding but do not involve in Watson-Crick base pairing.
Want to see more full solutions like this?
Chapter 8 Solutions
Loose-leaf Version for Lehninger Principles of Biochemistry 7E & SaplingPlus for Lehninger Principles of Biochemistry 7E (Six-Month Access)
- Sodium fluoroacetate (FCH 2CO2Na) is a very toxic molecule that is used as rodentpoison. It is converted enzymatically to fluoroacetyl-CoA and is utilized by citratesynthase to generate (2R,3S)-fluorocitrate. The release of this product is a potentinhibitor of the next enzyme in the TCA cycle. Show the mechanism for theproduction of fluorocitrate and explain how this molecule acts as a competitiveinhibitor. Predict the effect on the concentrations of TCA intermediates.arrow_forwardIndicate for the reactions below which type of enzyme and cofactor(s) (if any) wouldbe required to catalyze each reaction shown. 1) Fru-6-P + Ery-4-P <--> GAP + Sed-7-P2) Fru-6-P + Pi <--> Fru-1,6-BP + H2O3) GTP + ADP <--> GDP + ATP4) Sed-7-P + GAP <--> Rib-5-P + Xyl-5-P5) Oxaloacetate + GTP ---> PEP + GDP + CO 26) DHAP + Ery-4-P <--> Sed-1,7-BP + H 2O7) Pyruvate + ATP + HCO3- ---> Oxaloacetate + ADP + Piarrow_forwardTPP is also utilized in transketolase reactions in the PPP. Give a mechanism for theTPP-dependent reaction between Xylulose-5-phosphate and Ribose-5-Phosphate toyield Glyceraldehyde-3-phosphate and Sedoheptulose-7-Phosphate.arrow_forward
- What is the difference between a ‘synthetase’ and a ‘synthase’?arrow_forwardIn three separate experiments, pyruvate labeled with 13C at C-1, C-2, or C-3 is introduced to cells undergoing active metabolism. Trace the fate of each carbon through the TCA cycle and show when each of these carbons produces 13CO2.a. Glucose is similarly labeled at C-2 with 13C. During which reaction will this labeled carbon be released as 13CO2?arrow_forwardDraw the Krebs Cycle and show the entry points for the amino acids Alanine,Glutamic Acid, Asparagine, and Valine into the Krebs Cycle. How many rounds of Krebs will be required to waste all Carbons of Glutamic Acidas CO2?arrow_forward
- Suppose the data below are obtained for an enzyme catalyzed reaction with and without the inhibitor I. (s)( mM) 0.2 0.4 0.8 1.0 2.0 4.0 V without i (mM/min) 5.0 7.5 10.0 10.7 12.5 13.6 V with I (mM/min) 3.0 5.0 7.5 8.3 10.7 12.5 Make a Lineweaver Burke plot for this data using graph paper or a spreadsheet Calculate KM and Vmax without inhibitor. What type of inhibition is observed? show graph and work 2. Give the Lineweaver Burk equation and define all the parameters. 3. When substrate concentration is much greater than Km, the rate of catalysis is almost equal to a. kcat b. none of these c. all of these d. Kd e. Vmaxarrow_forwardPlease explain the process of how an axon degenerates in the central nervous system following injury and how it affects the neuron/cell body, as well as presynaptic and postsynaptic neurons. Explain processes such as chromatolysis and how neurotrophin signaling works.arrow_forwardPlease help determine the Relative Response Ratio of my GC-MS laboratory: Laboratory: Alcohol Content in Hand Sanditizers Internal Standard: Butanol Standards of Alcohols: Methanol, Ethanol, Isopropyl, n-Propanol, Butanol Recorded Retention Times: 0.645, 0.692, 0.737, 0.853, 0.977 Formula: [ (Aanalyte / Canalyte) / (AIS / CIS) ]arrow_forward
- Please help determine the Relative Response Ratio of my GC-MS laboratory: Laboratory: Alcohol Content in Hand Sanditizers Internal Standard: Butanol Standards of Alcohols: Methanol, Ethanol, Isopropyl, n-Propanol, Butanol Recorded Retention Times: 0.645, 0.692, 0.737, 0.853, 0.977 Formula: [ (Aanalyte / Canalyte) / (AIS / CIS) ]arrow_forwardplease draw it for me and tell me where i need to modify the structurearrow_forwardPlease help determine the standard curve for my Kinase Activity in Excel Spreadsheet. Link: https://mnscu-my.sharepoint.com/personal/vi2163ss_go_minnstate_edu/_layouts/15/Doc.aspx?sourcedoc=%7B958f5aee-aabd-45d7-9f7e-380002892ee0%7D&action=default&slrid=9b178ea1-b025-8000-6e3f-1cbfb0aaef90&originalPath=aHR0cHM6Ly9tbnNjdS1teS5zaGFyZXBvaW50LmNvbS86eDovZy9wZXJzb25hbC92aTIxNjNzc19nb19taW5uc3RhdGVfZWR1L0VlNWFqNVc5cXRkRm4zNDRBQUtKTHVBQldtcEtWSUdNVmtJMkoxQzl3dmtPVlE_cnRpbWU9eEE2X291ZHIzVWc&CID=e2126631-9922-4cc5-b5d3-54c7007a756f&_SRM=0:G:93 Determine the amount of VRK1 is present 1. Average the data and calculate the mean absorbance for each concentration/dilution (Please over look for Corrections) 2. Blank Correction à Subtract 0 ug/mL blank absorbance from all readings (Please over look for Corrections) 3. Plot the Standard Curve (Please over look for Corrections) 4. Convert VRK1 concentration from ug/mL to g/L 5. Use the molar mass of VRK1 to convert to M and uM…arrow_forward
- BiochemistryBiochemistryISBN:9781319114671Author:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.Publisher:W. H. FreemanLehninger Principles of BiochemistryBiochemistryISBN:9781464126116Author:David L. Nelson, Michael M. CoxPublisher:W. H. FreemanFundamentals of Biochemistry: Life at the Molecul...BiochemistryISBN:9781118918401Author:Donald Voet, Judith G. Voet, Charlotte W. PrattPublisher:WILEY
- BiochemistryBiochemistryISBN:9781305961135Author:Mary K. Campbell, Shawn O. Farrell, Owen M. McDougalPublisher:Cengage LearningBiochemistryBiochemistryISBN:9781305577206Author:Reginald H. Garrett, Charles M. GrishamPublisher:Cengage LearningFundamentals of General, Organic, and Biological ...BiochemistryISBN:9780134015187Author:John E. McMurry, David S. Ballantine, Carl A. Hoeger, Virginia E. PetersonPublisher:PEARSON





