- Email: [email protected]
From Sonia Corina Hess
Biochemicai Education ELSEVIER
Biochemical
Education
26 (1998)
182-183
Letters to the Editor PII: SO307-4412(98)00111-3
References
From Sonia Corina Hess
(a) A.L. Lehninger, Principles of Biochemistry, Worth, New York, 1982; (b) L. Shyer, Biochemistry, 3rd edn, Freeman, New York, 1988; (c) F. Bettelheim, J. Landesberg, Laboratory Experiments for Organic and Biochemistry, 2nd edn, Saunders, Forth Worth, 1995; (d) D. Voet, J.G. Voet, Biochemistry, 2nd edn, John Wiley and Sons, New York, 1995. PI F.A. Cotton, G. Wilkinson, P.L. Gaus, Basic Inorganic Chemistry, 7”,4 L,“,,) -rl.. J”llll T-i... XX,:lr.. ....A 0”1IJ, C.\“.. I.LvI hTa... “-*l, ill” r*,rcr a,,” 1 “Lh, 10P-l 170,. de Quimica corn Materials Domesticos, [31 S.C. Hess, Experimentos Moderna, Srio Paulo (Brasil), 1997.
[ll
Soya bean urease and peroxidase: with inexpensive materials
Interesting experiments
Dear Sir Urease is an -SH (thiol) group containing enzyme. Metals such as Ag(I), Hg(II), Pb(I1) and Cu(II), among others, form complexes with the -SH groups, inactivating the enzyme [l]. The ion Cu(I1) forms a deep blue complex with ammonia, and the formation of the complex can easily be seen by direct observation [2]. Urease is found in soy bean which also contains a peroxidase that catalyses the decomposition of hydrogen peroxide to generate oxygen and water [l]. Acidic media and the ions Fe(I1) and Cu(I1) inactivate peroxidases. Fe(I1) is produced when I.‘,“‘,
F.-(Cl\ 1 V,“,
~P~C+E with I” uyu’ CA~,,P~,,C wxl,rti,,~ l”UlLU VIAL11-11 vuu 0”I”LLV.I
nf “I
P,rlTT\ .,U\“,
From V H Mulimani The use of cycle chain model for tRNA for student use
121,. L-‘
Simple experiments can demonstrate the activity and the inhibition of urease and peroxidase from soy bean. The decomposition of urea (sold at stores specialising in articles for agriculture) in the presence of urease (solution prepared by grinding soy bean with water) can be detected by the smell of ammonia and also by taking samples of the mixture and adding to them a solution of Cu(I1). (Cu(II)SO, is sold at stores specialising in articles for pools). It is possible to observe the inhibition of urease by Cu(I1) by adding a solution of that ion to a solution of urea and then adding the soy bean suspension. The absence of colour or smell indicates that no reaction occurs. The decomposition of hydrogen peroxide by a peroxidase can be easily observed by the formation of bubbles containing oxygen that are produced when soy bean solution is added to an aqueous solution of H,O, (sold at drugstores). If the solution of H,O, is mixed with acetic acid (vinegar), or with a solution of Cu(II), or with a solution of Fe(I1) (obtained by the reaction of iron wool with Cu(I1) sulphate in water) [3], the addition of soy bean extract to the mixture causes no effect, indicating that the peroxidase is inhibited. For full details of materials and methods, write to the author asking for the complete paper. Sonia Corina Hess Departamento de Quimica Universidade Federal de Mato Gross0 do Sul Caira Postal 549 7on7n_om I,“,” ,“”
PII: SO307-4412(98)00045-4
rnmnn km ._...*‘.yY c:mnAo U~rxwur) I.-Y Brasil
Dear Sir The availability of suitable molecular models is very important in the teaching of biochemistry. The most common types of model: stick, ball and stick, space-filling, typically used in lectures on structure, isomerism, etc, are generally used only for the demonstration of the configuration of small molecules such as monosaccharides and amino acids. Although detailed drawings of tRNA conformations are included in every textbook of biochemistry, they are flat representations, with ~mwdin” nf YlYL‘ otnm~ anrl hnnrlr malrs=a U’““““‘6 “I lY YIaU ““La-“, whirh ,,111u11LllY‘ I”” thr LI.” vi~~~aliratinn ..“YUI.“ULI”.I nf “L tRNA difficult. For these purposes and for student use, tRNA models built using cycle chain provide the necessary flexibility. We used cycle chain with 77 rivets and paper discs are attached on the rivets. Simple materials like cardboard, nails, fevical and gum are used for making the model. Methodology for building cycle chain tRNA (Ala)
(1) Write
the single letter initials of the nitrogenous
the n~n~r ____ T-T_~
(2) Paste (3) (4) (5) (6) (7) 10, (01
bases on
discs -_l_l.
them on alternative rivets in the sequence shown in the Figure. Place the chain on the board and fold as shown. Fix its position with nail and fevical. Mark the 3’ and 5’ ends of the chain. Recognise the base pairs which can form hydrogen bonds, then join them. Label the anticodon region which is involved in the recognition of the codon. ,LLL”T;I ,.k,., *I., ..-:.... “,:A o,.0n.-.tr\r OLC‘ rtnm. II) LL‘GLllllll‘” a.c11lr.:..rl;..” “1I11l11.gc:t0 JIIG) ,PP,%\ \LX_.rXj acGtirJr”l variable loop and CCA end, DHU arm and TYC arm.
Biochemical
Education
26 (1998)
182-183
Letters to the Editor PII: SO307-4412(98)00111-3
References
From Sonia Corina Hess
(a) A.L. Lehninger, Principles of Biochemistry, Worth, New York, 1982; (b) L. Shyer, Biochemistry, 3rd edn, Freeman, New York, 1988; (c) F. Bettelheim, J. Landesberg, Laboratory Experiments for Organic and Biochemistry, 2nd edn, Saunders, Forth Worth, 1995; (d) D. Voet, J.G. Voet, Biochemistry, 2nd edn, John Wiley and Sons, New York, 1995. PI F.A. Cotton, G. Wilkinson, P.L. Gaus, Basic Inorganic Chemistry, 7”,4 L,“,,) -rl.. J”llll T-i... XX,:lr.. ....A 0”1IJ, C.\“.. I.LvI hTa... “-*l, ill” r*,rcr a,,” 1 “Lh, 10P-l 170,. de Quimica corn Materials Domesticos, [31 S.C. Hess, Experimentos Moderna, Srio Paulo (Brasil), 1997.
[ll
Soya bean urease and peroxidase: with inexpensive materials
Interesting experiments
Dear Sir Urease is an -SH (thiol) group containing enzyme. Metals such as Ag(I), Hg(II), Pb(I1) and Cu(II), among others, form complexes with the -SH groups, inactivating the enzyme [l]. The ion Cu(I1) forms a deep blue complex with ammonia, and the formation of the complex can easily be seen by direct observation [2]. Urease is found in soy bean which also contains a peroxidase that catalyses the decomposition of hydrogen peroxide to generate oxygen and water [l]. Acidic media and the ions Fe(I1) and Cu(I1) inactivate peroxidases. Fe(I1) is produced when I.‘,“‘,
F.-(Cl\ 1 V,“,
~P~C+E with I” uyu’ CA~,,P~,,C wxl,rti,,~ l”UlLU VIAL11-11 vuu 0”I”LLV.I
nf “I
P,rlTT\ .,U\“,
From V H Mulimani The use of cycle chain model for tRNA for student use
121,. L-‘
Simple experiments can demonstrate the activity and the inhibition of urease and peroxidase from soy bean. The decomposition of urea (sold at stores specialising in articles for agriculture) in the presence of urease (solution prepared by grinding soy bean with water) can be detected by the smell of ammonia and also by taking samples of the mixture and adding to them a solution of Cu(I1). (Cu(II)SO, is sold at stores specialising in articles for pools). It is possible to observe the inhibition of urease by Cu(I1) by adding a solution of that ion to a solution of urea and then adding the soy bean suspension. The absence of colour or smell indicates that no reaction occurs. The decomposition of hydrogen peroxide by a peroxidase can be easily observed by the formation of bubbles containing oxygen that are produced when soy bean solution is added to an aqueous solution of H,O, (sold at drugstores). If the solution of H,O, is mixed with acetic acid (vinegar), or with a solution of Cu(II), or with a solution of Fe(I1) (obtained by the reaction of iron wool with Cu(I1) sulphate in water) [3], the addition of soy bean extract to the mixture causes no effect, indicating that the peroxidase is inhibited. For full details of materials and methods, write to the author asking for the complete paper. Sonia Corina Hess Departamento de Quimica Universidade Federal de Mato Gross0 do Sul Caira Postal 549 7on7n_om I,“,” ,“”
PII: SO307-4412(98)00045-4
rnmnn km ._...*‘.yY c:mnAo U~rxwur) I.-Y Brasil
Dear Sir The availability of suitable molecular models is very important in the teaching of biochemistry. The most common types of model: stick, ball and stick, space-filling, typically used in lectures on structure, isomerism, etc, are generally used only for the demonstration of the configuration of small molecules such as monosaccharides and amino acids. Although detailed drawings of tRNA conformations are included in every textbook of biochemistry, they are flat representations, with ~mwdin” nf YlYL‘ otnm~ anrl hnnrlr malrs=a U’““““‘6 “I lY YIaU ““La-“, whirh ,,111u11LllY‘ I”” thr LI.” vi~~~aliratinn ..“YUI.“ULI”.I nf “L tRNA difficult. For these purposes and for student use, tRNA models built using cycle chain provide the necessary flexibility. We used cycle chain with 77 rivets and paper discs are attached on the rivets. Simple materials like cardboard, nails, fevical and gum are used for making the model. Methodology for building cycle chain tRNA (Ala)
(1) Write
the single letter initials of the nitrogenous
the n~n~r ____ T-T_~
(2) Paste (3) (4) (5) (6) (7) 10, (01
bases on
discs -_l_l.
them on alternative rivets in the sequence shown in the Figure. Place the chain on the board and fold as shown. Fix its position with nail and fevical. Mark the 3’ and 5’ ends of the chain. Recognise the base pairs which can form hydrogen bonds, then join them. Label the anticodon region which is involved in the recognition of the codon. ,LLL”T;I ,.k,., *I., ..-:.... “,:A o,.0n.-.tr\r OLC‘ rtnm. II) LL‘GLllllll‘” a.c11lr.:..rl;..” “1I11l11.gc:t0 JIIG) ,PP,%\ \LX_.rXj acGtirJr”l variable loop and CCA end, DHU arm and TYC arm.