Enzym

A       IDENTITAS

          Hari/Tanggal    : Selasa / 3 Juli 2012

          Waktu               : 14.30-17.30

B       KEGIATAN                  

          Enzym 

C       RINGKASAN KEGIATAN

          Sore ini kami mendapat materi praktikum tentang determination of reducing sugar by 3,5-dinitrosalicylic acid (DNS) reagent. Adapun tujuan praktikumnya: mempelajari bagaimana menggunakan centrifuge, mempelajari penggunaan yang tepat dari micropipettes, mempelajari operasi dasar dari spectrometer, dan mempelajari 3,5-dinitrosalicylic acid colorimetric method for the determination of reducing sugar. Alat dan bahan yang perlu dipersiapkan antara lain:

1.      Material

Tepung gandum.

2.      Instruments

Electronic balance: centrifuge, spectroohotometer, boiling water bath, gas bath thermostatic oscillator.

3.      Equipments

Graduated test tube: 25 mlX9

Pasteur pipette: 1 mlX2

Beaker: 250 mlX50 mlX1

Cone shaped bottle: 100 mlX1

Micropipette: 1mlX1

Plastic squeeze bottle, test tube rack, glass rod

4.      Reagent preparation

Glucose standard solution, DNS reagent

5.      Steps

·      Accurately weigh 5 g flour and put it in clean and dry cone shaped bottle

·      Dissolve the flour in 100 ml distilled water and mix it evenly

·      Put the flour suspension into 50^o C gas bath thermostatic oscillator for 30 min

·      Take 40 ml solution to a 50 ml tube, then centrifuge for 15 min at 8000 rpm/min

·      Collect the supernatant solution for reducing sugar analysis

·      Make a standard curve and calculate the content of reducing sugar in  the samples. Sandard glucose concentration gradient 0,2;0,4;0,6;0,8;1,0 ul. Samples 1,0 ulX3.

·      Mix each tube and boil them in boiling water bath for 5 minutes

·      Cool the tubes to room temperature, add deionized water to 25 ml and mix it evenly

·      Set the 0 tube (blank) to zero and measured the absorbance at the wavelegth of 540 nm

·      Record the data and process the result.

·      Set the glucose content as the abscissa, A540 as vertical axis, and draw standrad curve by computer

·      Calculate the evarage of A540 of the samplesa

·      According to the standard curve, calculate the content of reducing sugar in the samples.