Free Net Life Science Study Materials

CSIR JRF NET Life Sciences Model Question Paper for June 2017 Exam (Set 1/5)


Biosynthesis of purine & pyrimidine

CSIR JRF/NET Life Science Exam
June 2017 (I)
Model Question Paper 1/5
(Practice Questions with Answer Key)

(1). Action of topoisomerase leads to changes in

a.       Linking number of single-stranded linear DNA
b.      Lining number of double stranded linear DNA
c.       Linking number of closed circular single stranded DNA
d.      Linking number of closed circular double stranded DNA

(2). Sarcomas are cancers originating from:

a.       Spleen
b.      Lymph node
c.       Skin
d.      Connective tissue

(3). Receptor mediated endocytosis from plasma membrane requires which one of the following coat proteins

a.       Clathri
b.      Adaptin
c.       Arrestin
d.      Glycophorin

(4). Which of the following compound does not acts as ‘second messenger’ during signaling process?

a.       cAMP
b.      Calcium ions
c.       Inositol 3.4.5 triphosphate
d.      Triacylglycerol

(5). Which of the following peptide is not synthesized on ribosome?

a.       Cyclosporin
b.      Somatotropin
c.       Vasopressin
d.      Oxytocin

Continue reading

Free Net Life Science Study Materials

CSIR JRF NET Exam June 2017- Official Notification (Apply Online)


net life science 2017 apply online

CSIR JRF NET June 2017 Notification, Apply Online

Applications are invited from eligible candidates for the CSIR JRF NET Examination, June 2017. CSIR will hold the Joint CSIR-UGC Test Tentatively on Sunday 18th June, 2017 for determining the eligibility of the Indian National candidates for the award of Junior Research Fellowships (JRF) NET and for determining eligibility for appointment of Lecturers (NET) in certain subject areas falling under the faculty of Science & Technology. The award of Junior Research Fellowship (NET) to the successful eligible candidates will depend on their finding admission/placement in a university/ national laboratory/ institution of higher learning and research, as applicable.

Continue reading

biological chemistry

Physical and Chemical Properties of Water and its Biological Significance


biological significance of water

Physical and Chemical Properties of Water and its Biological Significance

Water is the most abundant substance in the living system. Water makes up about 70% or more of the weight of almost all organisms. The life has originated in remote past in the aqueous environment. The properties (both physical and chemical) of water enabled it as the ‘solvent of life’. The water possesses some unusual physical and chemical properties. These ‘unusual properties’ are responsible making water as the ‘solvent of life’. The present post describes the Physical, Chemical and Unusual Properties of Water. We will also discuss the importance or significance of these properties of water in the biological system.

The unusual properties of water are mainly due to three factors:

(A).  The small size of water molecules

(B).  The polarity of water molecules

(C).  The formation of hydrogen bonds between adjacent water molecules

Most important physio-chemical and unusual properties of water can be summarized into the following heads:

(1).  Solvent properties of water

(2).  High heat capacity of water

(3).  High heat of vaporization

(4).  High heat of fusion

(5).  Density and freezing properties

(6).  High cohesion, adhesion and surface tension of water

(7).  Water acts as a reactant

Continue reading

Biotechnology Lecture Notes

Batch Fermentation vs Continuous Fermentation Process: Similarities and Differences – A Comparison Table


Difference continuous and batch fermentation

Batch Fermentation vs Continuous Fermentation Process
(Similarities and difference between Batch Fermentation and Continuous Fermentation Process)

Batch Fermentation and Continuous Fermentation are the two commonly adopted Industrial Fermentation methods for the scale production of microbial biomass or metabolites.

Batch Fermentation: Here the fermenter is first filled with the raw material (carbon source). Then the microbes are added and allowed to ferment the raw material under optimum pH and aeration. The products remain in the fermenter until the completion of fermentation. After fermentation, the products are extracted and the fermenter is cleaned and sterilized before next round. Thus here the fermentation is done as separate batches.

Continuous Fermentation: Here the exponential growth rate of the microbes is maintained in the fermenter for prolonged periods of time in by the addition of fresh media are regular intervals. The metabolite or the product of fermentation is extracted for the overflow from the fermenter. Thus unlike batch fermentation, in continuous fermentation, the fermentation process never stops in between and it continues to run for a long period of time with the addition of nutrients and harvesting the metabolites at regular intervals.

The present post describes the Similarities and Differences between Batch Fermentation and Continuous Fermentation Process as a Comparison Table.

Similarities between Batch Culture and Continuous Culture Fermentation Methods

Ø  Both are industrial fermentation methods for the large scale production.

Ø  Both methods can be used for the production of microbial biomass or products.

Ø  Both run under controlled environmental conditions

Ø  The mechanical components of fermenter is almost similar in both types




Difference between Batch Fermentation and Continuous Fermentation Process

Continue reading

Biotechnology Lecture Notes

Industrial Fermentation Process (Batch, Fed-batch and Continuous Fermentation)


types of fermentation process

Fermentation Technology
(Types of Industrial Fermentation Processes)

Fermentation: An art from the past, a skill for the future…
Brain McNeil

What is fermentation?

Ø  Fermentation is a metabolic process which converts carbohydrates to alcohols, organic acids or gases by the activity of enzymes of microbial origin.

Ø   Microbes involved in fermentation process: Bacteria and Fungi.

Ø  The process of anaerobic respiration in the muscle cells of animals during exercise which produce lactic acid is also a type of fermentation.

Ø  The technique of fermentation was very ancient in origin.

Ø  Egyptians and Sumerians had the knowledge of the technique of converting starchy grains to alcoholics.

Ø  For a microbiologist, the word ‘fermentation’ means many processes such as:

$   A method of mass cultivation of microbes under aerobic or anaerobic conditions.

$   Any biological process occurs in the absence of oxygen.

$   Spoilage of food by microbial activity.

$   Production of alcoholic beverages, organic acids, antibiotics or biopolymers

$   Partial oxidation of carbohydrates

What is industrial fermentation?

Ø  The intentional use of fermentation technology for the large scale production of microbial biomass or metabolites is called industrial fermentation.

Continue reading