SPM Biology 2016

Question

2 . Diagram 2.1 shows a reaction of enzyme R on substrate P.

Rajah 2.1 menunjukkan tindak balas enxim R ke atas susbtrat P.

(a) (i) Name substrate P and enzyme R.

Namakan substrat P dan enzim R.

(ii) Explain process Q.

Terangkan proses Q.

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(b) Daigram 2.2 shows the stages in the reaction of enzyme R.

Rajah 2.2 menunjukkan peringkat-peringkat dalam tindak balas enzim R.

(i) Explain why enzyme R only acts on substrate P as shown at stage II in Diagram 2.2.

Terangkan mengapa enzim R hanya bertindak ke atas substrat P seperti yang ditunjukkan pada peringkat II dalam Rajah 2.2.

(ii) Only a small quantity of enzyme R is needed in the reaction. Explain why.

Hanya sedikit kuantiti enzim R diperlukan dalam tindak balas itu. Terangkan mengapa.

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(c) Diagram 2.3 shows the action of molecule X on enzyme R. Explain how the presence of molecule X affects the reaction of enzyme R with substrate P.

Rajah 2.3 menunjukkan tindakkan molekul X ke atas enzim R. Terangkan bagaimana kehadiran molekul X mempengaruhi tindak balas enzim R dengan substrat P.Cher Questions Solution Bank Rumusan Jawapan SPM & IGCSE Questions Answers Solution

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Answer ( 1 )

    2
    2021-01-06T11:13:46+08:00

    2. a)i)P: Lactose

    R: Lactase

    ii) -Q is a hydrolysis process which requires water to breakdown the bonds between molecules.

    -Larger molecules get broken down into smaller molecules

    -P(Lactose) is hydrolysed into glucose and galactose with the help of R(Lactase) and the addition of water.

     

    b)i) -Enzymes are very specific they only bind to a particular substrate.

    -P is able to bind and fit within the active site of R but S is not.

    ii)-Enzyme R doesn’t get destroyed and used up.

    -One enzyme can be used to catalyse the same reaction many times.

     

    c)-Molecule X is an inhibitor.

    -The inhibitor competes with substrate P for binding with active site of enzyme R. This inhibitor has a shape which allows it to fit into the active site.

    -Lesser chance for substrate P to bind to the active site. This reaction doesn’t get catalysed by R, it slows down.

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