biological chemistry

Enzyme Specificity (Biochemistry Lecture Notes)


Biochemistry of Enzyme Substrate Specificity and its Classification With Examples

.“There is more to life than increasing its speed…”

                                                                                    Mahatma Gandhi


Enzymes are biological catalysts. They accelerate the rate of metabolic reactions in the cells by reducing the activation energy of the reactants. Almost all enzymes are specialized proteins with definite structural conformations.

Important characteristic features of enzyme are:

1. Catalytic Power (ratio of enzyme catalyzed rate of a reaction to the un-catalyzed rate)

2. Regulation (control of enzymatic reaction)

3. Specificity (Selectivity of enzyme to their substrate)

What is enzyme specificity?

Specificity is the ability of an enzyme to choose exact substrate from a group of similar chemical molecules. The specificity is actually a molecular recognition mechanism and it operates through the structural and conformational complementarity between enzyme and substrate. Enzymes show different degrees of specificity towards their substrate.

how enzyme and substrate binds .. conformational asymmetry of enzyme and substrate

The specificity shown by enzymes are grouped into 6 categories

1.  Bond specificity

2.  Group specificity

3.  Substrate specificity

4.  Stereo specificity (Optical specificity)

5.  Geometrical specificity

6.  Co-factor specificity

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biology career opportunities and Notifications

JNU Faculty Job Vacancy May 2015: in Biotechnology, Molecular Biology & Nano science


Assistant Professor, Associate Professor and Professor Job Vacancy in Jawaharlal Nehru University (JNU), New Delhi: Notification, May 2015, Advt.No. RC/50/2015

The JNU has openings for faculty positions at the level of Professor, Associate Professor and Assistant Professor in the areas of specialization as indicated against each. The essential qualifications/ scales of pay for these positions are given below. Candidates with good academic record, teaching/research experience and working in related areas of research are encouraged to apply. University also solicits applications from candidates with research interests that are interdisciplinary.

Vacancies in Biological/Life Science at a glance

JNU Departments Post/Position No. of Vacancies Category
School of Biotechnology Professor 1 Unreserved
Associate Professor 2 Unreserved
Assistant Professor 1 SC
Assistant Professor 1 OBC
Centre for Molecular Medicine Associate Professor 2 SC 1, ST 1
Centre for Nano Sciences Professor 1 Unreserved
Associate Professor
(Exp. Nano Biology)
1 Unreserved
Associate Professor
(Nano-chemistry)
1 Unreserved

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mcq biology

Biology MCQ-04 Biochemistry: Carbohydrates – Part 3 for JRF/NET Life Science Examination


Biochemistry Quizzes

Biology MCQ (Multiple Choice Questions in Life Science)
(Sample/Model/Practice Questions for JRF/NET Life Science Examination, ICMR JRF, DBT JRF, GATE, ICAR NET, PG Entrance)


Biochemistry: Carbohydrates Part 3 (MCQ 04)


1. Which of the following is an example for a trisaccharide?

a.       Verbascose
b.      Stachyose
c.       Raffinose
d.      Sucralose

2. Chrysolaminarin is ________.

a.       A storage polysaccharide of green algae
b.      A storage polysaccharide of brown algae
c.       A storage polysaccharide of red algae
d.      A storage polysaccharide of diatoms

3. Which of the following is an example for an artificial sweetener of saccharide origin?

a.       Sucralose
b.      Saccharin
c.       Stachyose
d.      All of these

4. In a chemical reaction ‘X’ is able to convert Cu2+ ions to Cu+ ions. If ‘X’ is a carbohydrate, which of the following best explains to be the ‘X’?

a.       ‘X’ is a reducing sugar
b.      ‘X’ is a non-reducing sugar
c.       ‘X’ is a monosaccharide
d.      Both (a) and (b)
e.       Both (a) and (c)

5. Which of the following is a reducing sugar?

a.       Glucose in closed ring form
b.      Glucose in open chain form
c.       Sucrose

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mcq biology

Biology MCQ-03 Biochemistry: Carbohydrates – Part 2 for JRF/NET Life Science Examination


Biochemistry Quizzes

Biology MCQ (Multiple Choice Questions in Life Science)
(Sample/Model/Practice Questions for JRF/NET Life Science Examination, ICMR JRF, DBT JRF, GATE, ICAR NET, PG Entrance)


Biochemistry: Carbohydrates Part 2 (MCQ-03)


1.  The vitreous humor of eye is composed of_______.

a.       Heparin
b.      Hyaluronic acid

c.       Keratan Sulfate
d.      Chondroitin sulfate

2. N-acetyl glucosamine (NAG) and N-acetyl muramic acid (NAM) in peptidoglycan is connected by ____glycosidic linkage.

a.       α 1 – 4
b.      β 1 – 4

c.       α 1 – 2
d.      β 1 – 2

3.  Sulbactam is a ____________.

a.       β-lactam antibiotic
b.      β lactamase

c.       β lactamase inhibitor
d.      A class of penicillin

4.  Which of the following is not a sugar molecule of the O-antigen of gram negative bacteria?

a.       Tyvelose
b.      Abequose

c.       2 keto-3-deoxyoctanoate
d.      Teichoic acid

5.  Glycosidic bond between galactose and glucose in lactose is____.

a.       α 1 – 4
b.      β 1 – 4

c.       α 1 – 2
d.      β 1 – 2

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mcq biology

Biology MCQ-02 Biochemistry: Carbohydrates – Part 1 for JRF/NET Life Science Examination


Biochemistry Quizzes

Biology MCQ (Multiple Choice Questions in Life Science)
(Sample/Model/Practice Questions for JRF/NET Life Science Examination, ICMR JRF, DBT JRF, GATE, ICAR NET, PG Entrance)


Biochemistry: Carbohydrates Part 1 (MCQ-02)


1. The general chemical formula of carbohydrate is

a.       (CH2O)n
b.      (CH2O)2n

c.       (CHO)n
d.      CnH2nO

2. Which of the following is an aldotriose?

a.       Dihydroxyacetone
b.      Glyceraldehyde

c.       Ribulose
d.      Erythrose

3. What is the molecular formula of sucrose?

a.      C12H22O11
b.      C10H20O10

c.       C6H12O6
d.      C12H20O11

4. The glycosidic linkage between glucose molecule in maltose is

a.      β 1 – 4
b.      α 1 – 2

c.       α 1 – 4
d.      β 1 – 2

5. A keto pentose will have _____ sterioisomers.

a.      4
b.      6

c.       8
d.      10

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