Biomolecules Questions and Answers

Which of the following monosaccharides will form D glucaric acid structure below upon oxidation with nitric acid Cooll I OH HOT H H OH H OH COOH Select one OA OB O C CH OH D Glucitol H OH HOR OD A and B OE A and C H OH CH OH CH 01 L Glucose H OH H OR HO H H OH HOHO HORO D Glucose ON HOT H HU TOH H TOH CH OH

1 Which of the following statements about protein secondary structure is not true a Secondary structure gives the location and directionality of the backbone of proteins not R groups b Inter chain interactions between two parts of a polypeptide chain can occur in beta sheets c Protein secondary structure in maintained by hydrogen bonding between R groups and the backbone of proteins d Alpha helices are all right handed

8 A 5 solution of cane sugar molecular weight 342 is isotonic with 1 solution of substance X The molecular weight of X is 1 171 2 2 68 4 3 34 2 4 136 2

Oxyhemoglobin is diamagnetic due to electron spin coupling betwee A Low spin Fe and oxygen molecule B High spin Fe and superoxide radical C High spin Fe2 and oxygen molecule D Low spin Fe and superoxide radical

40 Which of the following properties of glucose cannot be explained by its open chain structure i Glucose does not form hydrogen sulphite with NaHSO ii On oxidation with HNO3 glucose gives saccharic acid iii Glucose is found to exist in two different crystalline forms which are named as a and B a ii only b i and iii c ii and iii d i and ii uiches proline from natural a amino acids

1 Which substance has the weakest attractions between its molecules Oformic acid O benzene O castor oil Ophenol Substance Melting Point C castor oil phenol benzene formic acid 9 8 43 2 5 7 8 K

Percentage of free space in cubic close packed structure and in body centred structure are respectively 1 48 and 26 2 30 and 26 4 32 and 48 3 26 and 32

head tail 10 H N CH n COOH mol wt x head tail HOOC CH m OH Product mol wt y If product has mol wt x y 18 then it is ar example of 1 Head to head condensation 2 Head to tail condensation 3 Tail to tail condensation Roth 1 3

example of a motif is the helix turn helix motif which can have DNA binding activity At whic rotein structure does a motif belong one of the above between secondary and tertiary etween tertiary and quaternary Sove quaternary etween primary and secondary

13 Consider a compound RR C OH X Identify X if the compound is hemiacetal a CN B NH C OH d OCH 14 Which of the following is product of the reaction of propanal with NH NHC H a imine b Shiff s base c phenylhydrazone d gem diol

Which of the following molecules is an Aldopentose O O HO HO CH OH FO H H CH OH CHO H HO H OH HO H H OH CH OH LO CHO H HO H OH HO H CH OH CH OH To HO H 11

For soap molecules to remove and dissolve oil in water what molecular features are needed A one end of the molecule must be polar B the compound must contain oxygen atoms C one end of the molecule must be nonpolar Both A and C All A B and C

Triglycerides are used for catalysis in the body made of fatty acid monomers always unsaturated soluble in water Select all that apply Saturated fatty acids contain functional groups carboxylic acid alkenes halogen amine alkanes

CO5 Advanced a The enzyme glucose isomerase can be used to convert glucose into fructose a much sweeter sugar The reaction is O C H 1 H C OH HO C H H C OH H C OH H C H OH Glucose Glucose isomerase OH H C H C 0 Several grades of glucose are available to be used in a fresh feed Glucose with a 1 weight percent inert impurity Glucose with a 5 weight percent inert impurity Glucose with a 10 weight percent inert impurity HO C H H C OH H C OH H C H OH Fructose The fructose can be sold for 0 44 lb It is estimated that a new plant can process about 18 000 lb hr of fresh glucose feed The process has been studied in the laboratory and about 60 of the glucole unconverted in fructose It is estimated that the annualized cost of a reactor and separator handmg 1800 lb hr of total fresh feed would cost 150 000 yr You may assume that this cost increased with the reactor size to the 0 7 power You may also assume that the separator achieves 100 separation of the glucose fructose mixture All the inerts leave with the glucose 0 220 1b 0 178 lb 0 167 lb Design a process to isomerize 18 000 lb hr of fresh glucose feed and produce pure fructose with maximum annual profit You may assume the process runs 24 hours day Derive any balances that may describe the system Define a variable x to stand in for the glucose in the fresh feed and a variable y to represent the fraction of glucose in the recycle and purge streams Let R be the size of the recycle stream and P be the size of the purge stream Substitute your balances into each other until you have one equation with x y and R undefined Using a spreadsheet set up separate tables for each value for x Then in each table define a range of y values y 01 y 02 y 03 etc You may find this easiest to have a separate row for each value of y Using your equations you should then be able to solve for R P all other variables the cost of the reactor the profit from product and the overall net gain Plot your value of y against the net gain for each of the three impurity percents Which operating condition recycle purge ratio impurity in feed etc gives you the highest possible profit Is the recycle purge ratio a value that you would expect PARS

Aspirin has a density of 1 40 g cm What is the volume of an aspirin tablet in cm weighing 250 mg

Amino acids are compounds that con tain both amine and organic acid functional groups Which compound is an amino acid 1 H OH H C C 3 HH 2 H OH H III H C C C N HHH 4 O O OH HO H C C N I H H H H H

Cung Hyu H H t Each Carbon has 4 BUNDS NH H sil OH H HH H H Paclitaxel Taxol C HO 0 H H H until OH H O H H

How many of the following compounds are steroids HO Im H H C CH H C D H CH Ill H H H Q H C H OH H CH H CH H H H C O CH I B H CH OH E OH CH

Which ONE of the following reagents would be best suited to detect the presence of an important Cysteine on the cell surface of a protein Carboxypeptidase A Streptavidin

Identify the constituents of this nucleotide NH HO 1 0 11 HO P O OH N OH O a adenine ribose phosphate group O b guanine ribose phosphate group O c adenine deoxyribose phosphate group hosphate groun

Which of the following reactions can be catalyzed by a decarboxylase a OH OH G b HO CH CH C 0 NH3 i H3NCH CH CH HO CH CH NH3 H C CH CH C O

mistry What is the right option and why The figure below shows a cartoon of the reaction of a lactam antibiotic in the active site of transpeptidase R OH SER R The mechanism of reaction is SN2 IZ Which ONE of the following statements about the reaction is INCORRECT HN SER The B lactam has reactivity similar to an ester The product ester is protected from bulk water and enzymes so is not easily hydrolysed The driving force for the reaction comes from release of ring strain in the B lactam The carboxylate group could form an ion pair with amino acid residues of the protein S

OH I C OOC CH CH OPO OP O3 OOC CH CH OH ob

Which of the following does not involve nuclear chemistry Atomic Bombs The sun A combustion reaction Fusion Fission

Chemistry How would the following fatty acid be classified CH3 CH2 CH CH 2 CH2 5 COOH Question 9 options omega 3 and polyunsaturated omega 6 and polyunsaturated omega 3 and unsaturated

VI Answer the following questions a draw the structure of guanine deoxiribonucleotide 6 What is the following IUPAC name of the following Br 2 1 H C CH3 0 CH 3 H HO H OH H OH OH Draw the structure of the peptide following sequence of amino acids Cys Thr Ser Ile Cys d Draw the structure of Alpha D altropiranosa o stained from the

Draw the skeletal line structure of the triacylglycerol that could be formed from oleic acid

following structure in an example of O II H N CH C N CH C N CH C 00 H H 11 H 948 CH T OH O a amino acid O b protein O c O d tripeptide hydrocarbons CH I C O OH

CH H N CH COH CH structure in an example of 010 i NH C10 O a amino acid O b O c protein O d carboxyl acid hydrocarbons

Problem 1 Circle and name the following parts of an amino acid a amino groups use red ink b a carbon use blue ink c carboxyl group use green ink d R side chain use black ink H N HO NH OH HO NH CH3 of hoo NH OH NH NH HN HO NH CH3 NH NH OH NH OH

34 5L of carbon dioxide gas at 1atm and 200 C is reacted with excess water What mass of glucose C6H12O6 would be formed Reaction 6CO2 g 6H O g C6H12O6 902 g

9 Identify each of the following as part of the primary secondary tertiary or quaternary structure of a protein a Hydrogen bonds form beta sheets b Amino acids join through peptide bonds to make a polypeptide c Several different polypeptides form a single biologically active protein d Polar side chains are attracted by aqueous parts of the surroundings while nonpolar side chains are repelled This causes the protein to form into a specific three dimensional shape e The polypeptide coils into a stabilized helix because of hydrogen bonds that occur between the first and fourth amino acid groups

7 What is the isoelectric point of the following peptide pKa values are provided A pl 8 0 B pl 5 5 C pl 6 0 D pl 3 5 H N ZI OH LOH group NH3 COzH sidechain pka 8 0 3 0 4 0

8 What is the correct description of the following peptide A Tripeptide B Tetrapeptide C Pentapeptide D Polypeptide H N OH

9 What is the formal charge on the following peptide at pH 5 0 H N A 2 B 1 C 0 D 1 E 2 OH NH group pka NH3 9 1 COzH 2 9 sidechain 8 3

In the slowest rate determining step of the reaction mechanism for citrate synthase what is the role of the histidine OXC Oxaloacetate CH COO HC C SCA H CO 70XC CH HC C SCA Coo HO O Nucleophilic attack on oxaloacetate O Stabilize the enolate intermediate through hydrogen bonding O Hydrolysis of acetyl CoA O Induce a pKa shift in citrate 0

ein Syniesis EXERCISE DNA and RNA Secondary Structures 5 G G C A T A G A 3 Create the complementary strand for this DNA fragment Remember to label the 3 and 5 ends of the new DNA strand References

H N CH CN CHCN CHC 0 CH CH CH CH CH3 C O NH b Give the full name of the amino acid at the C terminal end of this tripeptide H H N CH C N CH 6 6 6 CH 0 0 i H CH CH CH3 CH3 CH C CH C O T OH

H C H3C CHO 50 OH CH CH CO H H CH CH CH CO H C C H OH Saturated H C OH H CH CH CH CH CH CO H CH CH 7 CH3 C C CH3 CH CO H H Unsaturated

Consider the amino acids glycine valine and lysine a How many tripeptides can be formed from these three amino acids if each is used only once in the structure b Using three letter abbreviations for the amino acids give the sequence of each of the possible tripeptides c Draw the structure of the dipeptide that has valine at its N terminal amino acid and glycine as its C terminal amino acid Circle each peptide bond

8 Write the balanced nuclear equations for the Beta Alpha and Gamma decay of Radium 226 9 How are the mass number and atomic number of the nucleus affected by the loss of the following a beta particle b alpha particle c gamma particle

Do the following for your first oil fat a Draw the skeletal structure of the predominant fatty acid on a piece of paper b Circle the hydrophilic portion of the fatty acid c Draw a square around the hydrophobic portion of the fatty acid

H The monosaccharide a is a ketose is produced shown here b is a D sugar c is an aldose H HO H MO CHO OH OH 4

A 40 0 glucose solution is available How many mL of this solution is needed to make 24 0 glucose solution with a total volume of 74 0 mL Your Answer

require more than one step CHOOSE 6 of the following 7 Place a star next to the synthesis yo DO NOT want graded

20 Draw a cis fatty aci 21 Which fatty acid in the figures below would you expect to be most soluble in water HO HO 22 Which fatty acid in the figures below will have a higher melting point HO Octanoic acid trans Oleic acid OH

oltr OH will close 14 H 4 Step 6 Show structures of a and B variations of the D Sorbose CH OH CH OH ot H H H 0H 1204 YOH a sorboyamone OH H 6H ot Step 7 Explain how a and variations of the D Sorbose differ from each other T H OH B JOH CH OH Sorborum

Draw a triacylglycerol (triglyceride) made from glycerol, myristic acid [CH, (CH₂),,COOH), palmitic acid [CH,(CH₂),COOH), and oleic acid [CH, (CH₂),CH=CH(CH₂),COOH(cis)]. Place palmitic acid at the middle position. Cis/trans isometry is graded; it may help to draw hydrogen atoms associated with the carbon atoms of the double bond.

How many hydrogen bonds can form between any tetrose sugar and water molecules? 4 9 8 12

In the peptide, Ala-Leu-Cys-Met, there are__ peptide bonds and the amino terminal is the amino acid A. 4; Alanine B. 4; Methionine C. 3; Methinine D.3; Alanine E. 3; there is no amino end