Agriculture Test - 3

The correct answer is Beauveria bassiana Key Points

•  Beauveria bassiana (Hyphomycetes) is a pathogenic fungus that infects a wide range of insect species, including the Colorado potato beetle.
• Live fungi are used to combat insect pests of crop plants and to control the growth of weeds.
• Beauveria bassiana is an entomopathogen used to control crop infestations by aphids, thrips, and whitefly.
• The insect disease caused by the fungus is a muscardine which has been called white muscardine disease.
• When the microscopic spores of the fungus come into contact with the body of an insect host, they germinate, penetrate the cuticle, and grow inside, killing the insect within a matter of days.

Additional Information The Colorado potato beetle,  Leptinotarsa decemlineata Chrysomelidae Coleoptera.

• It is also known as the Colorado beetle, the ten-striped spearman, the ten-lined potato beetle, or the potato bug, is a major pest of potato crops.
• It is about 10 mm long, with a bright yellow/orange body and five bold brown stripes along the length of each of its elytra.

The correct answer is FrankiaKey Points

• Frankia is a nitrogen (N)-fixing multicellular actinomycete which establishes root-nodule symbiosis with actinorhizal plants.
• The plants that form symbiotic relationships with Frankia are called actinorhizal plants.

Actinomycetes are a remarkable type of bacteria, they function in at least three important ways.

• The Streptomyces family provides us with many of the important antibiotics we use in medicine today,
• The Frankia family works in a symbiotic relationship with many non-legume plants as nitrogen-fixing bacteria.
• Other actinomycetes are decomposers digesting tough plant tissues like the cellulose and lignin in bark, paper and stems and the chitin or hard exoskeletons of insects.

Additional Information

The correct answer is B-complex.

Key Points

• A group of water-soluble vitamins is defined as the Vitamin B complex. 
• Vitamin B complex contains 8 different components namely B2, B2, B3, pantothenic acid, B6, folic acid, biotin, and B12. 
• Folic acid is the artificial form of folate and naturally existing B vitamin.
• It is also called vitamin B9.
• Pantothenic acid is the naturally existing B vitamin that synthesis of coenzyme.
• It is also called vitamin B5.

The correct answer is legumesKey Points

•  Legumes are able to form a symbiotic relationship with nitrogen-fixing soil bacteria called rhizobium.
• The result of this symbiosis is to form nodules on the plant root, within which the bacteria can convert atmospheric nitrogen into ammonia that can be used by the plant.

picture showing root nodule on plant roots.Additional Information

• Rhizobium is a genus of Gram-negative soil bacteria that fix nitrogen.
• Rhizobium species from an endosymbiotic nitrogen-fixing association with roots of (primarily) legumes and other flowering plants.
• A legume is a plant in the family Fabaceae or the fruit or seed of such a plant. When used as a dry grain, the seed is also called a pulse. 

The correct answer is Vitamin B_12.

_{Key Points}

• Vitamin B₁₂ is a water-soluble organic compound that is essential for the production of red blood cells in humans.
• If Vitamin B12 is low, the red blood cells will not multiply which leads to Anemia.
• It contains a unique metallic ion called cobalt. 
• Cobalt is available in the major part of the Vitamin B₁₂ structure.
• Vitamin B12 is also known as cobalamins.

The correct answer is pH of buffer 1 > pH of buffer 2 > pH of buffer 3Key Points

1. 10 ml acid + 90 ml base = 80 ml basic solution, small equilibrium shift
2. 50ml acid + 50 ml base = neutral, no equilibrium shift
3. 90ml acid + 10 ml base= acidic solution , small equilibrium shift

​Here, the pH of the basic solution will be more then neutral and pH of neutral solution is more than the acidic solution.So, pH of buffer 1 > pH of buffer 2 > pH of buffer 3Additional Information

•  A buffer solution is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa.
• Its pH changes very little when a small amount of strong acid or base is added to it.
• Le Chatelier's principle states that - "If an equilibrium is subjected to a change of concentration, pressure or temperature, the equilibrium shifts in the direction that trends to undo the effect of the change".

The correct answer is Protein part of conjugate enzymesKey Points

• Apoenzyme is a term that is used to describe the protein part of a holoenzyme or conjugate enzyme.
• An apoenzyme is a type of enzyme which is inactive.
• The activation of the apoenzyme occurs upon binding of an organic cofactor or an inorganic cofactor with it.
• A cofactor required by an apoenzyme can be a metal ion, e.g. Mg2+, Fe3+, etc. or an organic molecule called coenzyme such as NAD+, NADP+, FAD2+, etc.

Confusion Points 

• Coenzymes are non-protein organic complexes, which are loosely attached to the protein part, e.g. NAD+, NADP+, etc.
• The cofactor, which is tightly bound to an apoenzyme is known as a prosthetic group, e.g. heme prosthetic group attached to catalase, peroxidase, etc.
• An apoenzyme becomes enzymatically active when bound to its cofactors and is now known as a holoenzyme.

The correct answer is Enzyme precursor Key Points

• A zymogen, also called a proenzyme, is an inactive precursor of an enzyme
• Any group of proteins that display no catalytic activity but are transformed within an organism into enzymes, especially those that catalyze reactions involving the breakdown of proteins are zymogen.
• A zymogen requires a biochemical change for it to become an active enzyme.
• The biochemical change usually occurs in Golgi bodies, where a specific part of the precursor enzyme is cleaved in order to activate it.

Additional InformationEnzyme poisons are basically enzyme inhibitors.

• Enzymes gave a wide variety of many important functions in any biological system, which makes life possible.
• Any substance which can inhibit their activity and cause a loss to biological processes, which may be life-threatening, are enzyme poisons or enzyme inhibitors.

Enzyme modulators are agents able to inhibit or activate enzymes.

The correct answer is Km value Key Points

• The catalytic efficiency of two different enzymes can be compared by comparing their Km value or Michaelis Menten constant.
• The Michaelis constant is the substrate concentration at which the reaction rate is at half-maximum.
• The Km describes the affinity of enzyme for a substrate molecule. 

The correct answer is precipitation of proteins using ammonium sulphate.

Key Points

• Protein solubility is influenced by the presence of ions. 
• At very high ionic strength, the protein solubility will decrease known as salting-out.
• Salting-out involves separating proteins depending on their solubility at a high concentration of salt.
• Ammonium sulphate is added with E. coli in the process of precipitation of proteins.