Ask Question, Ask an Expert

+1-415-315-9853

info@mywordsolution.com

Ask Chemistry Expert

Cytosine is one of the four bases which are used in the genetic code. It has the molecular formula C4H5N3O. The molecular structure of cytosine computed using Spartan with a 3-21G* basis set is displayed below.

problem 1: Draw an electron-dot (valence bond) structure of cytosine. Display all the lone pairs. Using your electron-dot structure, predict the structure and hybridization of the heavy atoms. Use your structure to describe why cytosine is categorized as a base.

problem 2: Calculations and experiments like X-ray crystallography show that cytosine possesses a plane of symmetry. That is, all the atoms lie in the same plane.

a) What does the molecular planarity imply regarding the hybridization of the heavy atoms?
b) Where are the lone pairs on the N and O atoms, in the plane of the molecule or perpendicular to the plane?
c) Is the hybridization adequate to describe global planarity? Describe.

problem 3: Draw a resonance structure for cytosine. Which of the two resonance structures that you have drawn makes the bigger contribution to the wave function? Describe why.

problem 4: The given bond lengths in Å were measured in compounds in which there is only one electron-dot structure, that is, no resonance: C-C, 1.54; C=C, 1.32; CΞC, 1.20; C-N, 1.47; C=N, 1.26; CΞN, 1.16; N-N, 1.47; N=N, 1.25; NΞN, 1.10; C-O, 1.43; C=O, 1.20.

The given bond lengths in Ångstrom were determined from the Spartan structure of cytosine: C1-N1, 1.37; N1-C2, 1.30; C2-C4, 1.41; C4-C3, 1.37; C3-N2, 1.35; N2-C1, 1.42; C3-N3, 1.35; C1-O1, 1.21. Interpret such cytosine data by using your resonance structures.

problem 5: Cytosine has some isomers. Draw the structures of those isomers with similar ring structure, that is, the carbon atoms and two of the nitrogen atoms lie in a 6-membered ring. Consideration of such isomers was significant in the elucidation of the structure of DNA by Watson and Crick.

156_cytosine.jpg

Chemistry, Academics

  • Category:- Chemistry
  • Reference No.:- M93224

Have any Question? 


Related Questions in Chemistry

A 100 l flask is filled with 100 g of argon at 25 c a

A 1.00 L flask is filled with 1.00 g of argon at 25 °C. A sample of ethane vapor is added to the same flask until the total pressure is 1.350 atm. What is the partial pressure of argon in the flask and what is the partia ...

A cleaning solution is found to have a oh- 32 x 10-12m

A cleaning solution is found to have a [OH-] = 3.2 x 10 -12 M. What is the [H 3 O + ] and is the solution acidic or basic?

How many seconds will be required to produce 10 g of

How many seconds will be required to produce 1.0 g of chromium metal by the electrolysis of a Cr(NO3)3 solution using a current of 3.0 A? Could someone please help me with the work for this.

Identify the atoms that are oxidized and reduced the change

Identify the atoms that are oxidized and reduced, the change in oxidation state for each, and the oxidizing and reducing agents in each of the following equations: a) Mg(s) + NiCl2(aq) ? MgCl2(aq) + Ni(s) b) PCl3(l) + Cl ...

Please respond to one of the below questions in detail

Please respond to ONE of the below questions in detail. These questions are taken from Sam Kean's "Questions and Topics for Discussion".  Your response needs to be 1-2 pages long, or approximately 700-900 words. Consider ...

A 15-gram sample of neon is placed in a sealed container

A 15-gram sample of neon is placed in a sealed container with a constant volume of 8.5 liters. If the temperature of the container is 27ºC, which of the following expressions gives the correct pressure of gas? The ideal ...

A 010 m fes04 aq solution is electrolyzed between a

A 0.10 M FeS04 (aq) solution is electrolyzed between a magnesium cathode and a platinum anode with a current density of 1.50 mA cm-2.The hydrogen over potential is 0.60 V. What will be the concentration of Fe2+ions when ...

One method to produce nitrogen in the lab is to react

One method to produce nitrogen in the lab is to react ammonia with copper (II) oxide: NH3(g) + CuO(s) Cu(s) + H2O(l) + N2(g). After using 40.0 grams of NH3, 15.5 grams of N2are produced. What is the percent yield of nitr ...

How many moles of carbon dioxide are produced when 193 mol

How many moles of carbon dioxide are produced when 19.3 mol of propane gas is burned in excess oxygen? C3H8+5O2=3CO2+4H2O? Please show work.

Aim - to understand the fundamentals of atomic structure

Aim - To understand the fundamentals of atomic structure, chemical bonding, periodic tableandits application in engineering problems - Objective - Observing and explaining the reasons of engineering chemistry related pro ...

  • 4,153,160 Questions Asked
  • 13,132 Experts
  • 2,558,936 Questions Answered

Ask Experts for help!!

Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

Ask Now Help with Problems, Get a Best Answer

WalMart Identification of theory and critical discussion

Drawing on the prescribed text and/or relevant academic literature, produce a paper which discusses the nature of group

Section onea in an atwood machine suppose two objects of

SECTION ONE (a) In an Atwood Machine, suppose two objects of unequal mass are hung vertically over a frictionless

Part 1you work in hr for a company that operates a factory

Part 1: You work in HR for a company that operates a factory manufacturing fiberglass. There are several hundred empl

Details on advanced accounting paperthis paper is intended

DETAILS ON ADVANCED ACCOUNTING PAPER This paper is intended for students to apply the theoretical knowledge around ac

Create a provider database and related reports and queries

Create a provider database and related reports and queries to capture contact information for potential PC component pro