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Catalyst and Enzyme :Similarities and Dissimilarities

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 Enzymes are biocatalysts.  Catalyst are those which accelerat the rate of reaction without affected itself.  Enzymes is a substance that catalyse biochemical reactions.  Similarties They do not initiate the reaction.  They constitute short -lived complexes by reacting with substrate molecules.  Both catalyse reversible reactions.  They increase the rate of reaction by lowering the activation energy.  They have no effect on equillibrium.  Both are effective in very small amounts.  Their quantity and quality remains unchanged in the reaction. The function of both catalyst and enzyme is to hasten the process in either direction.  Dissimilarities  Chemical nature   Enzymes are proteinous in nature while inorganic catalyst are small mineral ion.  Control   Enzyme activity can be controlled by certain regulators which can change the conformation of enzymes,catalyst are not controlled by regulators.  Effect of external factors   Enzymes are high sensitive to pH and temperature changes. Whe
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Enzymes

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 Definition : Enzymes are water soluble, colloidal organic macromolecules which are wholly or partially proteinaceous in nature; biological in origin;  produced in microamounts and capable of catalyzing specific biochemical reactions under specific conditions of temperature and pH.  Chemical nature  All enzymes are proteins but all proteins are not enzymes . Enzymes are wholly or partially proteinaceous in nature. This was first shown by J. B. Sumner.  and further supported by Northrop.  Both enzymes and proteins, when boiled with strong acid or base, undergo coagulation and lose their biological function.  Enzymes, like the protein, are macromolecules having high molecular weight ranging from 12,000 to 1million Daltons. Enzymes, on hydrolysis, yield a mixture of amino acids.  Enzymes and proteins both do not pass through dialyzing membrane.  Both are colloidal in nature    Importance of Enzymes A biological system needs the enzymes for two reactions : Metabolic actions occur at contr
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Physical and chemical properties of protein

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Most protein are colorless amorphous substance with no definite melting points or boiling points . On heating they undergo decomposition .  They forms important part of buffer system of body fluid as they are amphoteric in nature. This is due to large number of ionizable R-groups .  Isoelectric Point : This is because of presence on the protein chain of additional acidic or basic groups that are not involved in peptide linkages. Most proteins show minimum solubility and stability at their Isoelectric Point.  Precipitation / coagulation : proteins are easily precipitated by certain agents. Many of the normal function in body are essential precipitation reaction example clotting of blood. Precipitation of protein is an irreversible change and precipitated protein is said to be denatured.  Colloidal nature : These form colloidal dispersion in water. The inability of proteins to pass through a membrane is of great importance in body. Protein present in bloodstream can't pass thr
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Classification of Proteins

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 Presently there is no single system of classification of proteins is completely satisfactory. Following are the various system of classification of proteins on the basis of solubility, shape, structure, chemical composition and nature of amino acids.  On the basis of solubility  On the basis of solubility proteins are divided into following 7 categories .  Albumin : These are soluble in water, dil. Salt solution and dil. Acids and bases. They have property of coagulation on heating and these get precipitated with high salt concentration. Example : Egg albumin, serum albumin, lactalbumin(present in milk), legumelin (present in soyabeans ).   Globulin : These are insoluble in water but freely soluble in dil, salt solution. These are precipitated by half saturated salt solution. Example : Serum globulin, vitellin (egg yolk), Tuberin (potato), Myosinogen (muscles).    Glutelins : These are insoluble in water and salt solution but soluble in dilute acids and alkaline.  Example :Gluteni
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Protein Intro and specificity

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  These are complex nitrogenous organic biopolymer of amino acids showing great diversity in their organization.  Facts about proteins  The term protein was first coined by Jones J. Berzelius from Greek word " proteious " which means 'to hold first position '. It is abundant intracellular * organic biomolecule. It contributes 12% in cellular pool . These are next to water in cellular pool.  It constitute 50% or more of dry weight of cell.  Proteins form                      20% of mammalian muscles                     7% of blood plasma                     3.5% of cow milk                     12% of cereals                     20% of peas and nuts and pulses  There are 3000 types of proteins in E. Coli ,1 lakh different types of proteins in humans . 10 raise to power 10 -10 raise to power 12 different types of biomolecules  are found in about 1.5million species.  There is a co-relation between structure of proteins and their biological function which in turn
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Shell Coiling in snails 🐌

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 Maternal inheritance V/S Predetermination  Maternal inheritance : Inheritance of some traits of mother to the offspring through the cytoplasm of female gamete.  Predetermination : It is the effect of mother's genes on the characters of offspring through the cytoplasm of egg and embryo without involving plasmagenes of cytoplasm.  Shell coiling in snails 🐌  There are two types of coiling present in present in snails. 1.Dextral type 2. Sinistral type  The direction of coiling in shell is controlled by the orientation of mitotic spindle of the first cleavage of zygote. This all depends on the organization of egg before fertilisation. The spindle organisation is controlled by organisation of cytoplasm in the egg.  Dextral type : Shell is coiled clockwise (toward right when viewed from apex). It is shown by ( DD or Dd ) because D is dominant over d.  Sinistral type : Shell is coiled anticlockwise . It is shown by dd . 1.Cross between sinistral Female and Dextral male When eggs of Si
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Plastid inheritance in mirabilis

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 Plastid Inheritance in mirabilis The extra nuclear Or cytoplasmic inheritance of colour in plants plastids* was first discovered by Correns in Mirabils jalapa .  Mirabilis jalapa plant can bear 3types of branches  i.e. green , variegated and pale (or white).  Correns found that : The flowers on green branches produced plants only with green leaves irrespective of genotype or phenotype of pollen parent, The flower on pale branches produced only pale plants regardless of genotype or phenotype of pollen parent. Flowers of variegated branches formed seeds which give rise to 3types of plants : green, pale, variegated.  The type of branch giving pollen grains hardly matters for this type of inheritance. This is due to random distribution of green and colorless Plastid at the time of female gamete formation.  * Plastid : These are semi -autonomous organelle which have their own DNA, replication, transcription and translation machinery. Three types of Plastid can be identified : C
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Nuclear inheritance in paramecium (Kappa particles (K))

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 Kappa particles in Paramecium    Sonneborn   found two types of strain in paramecium .i. e. Killer and sensitive .  Killer strain : Killer strains contain Kappa particles *  .These strains produce a poisonous substance called paramecin with the help of kappa particles.  These kappa particles remain unaffected in presence of paramecin.  * kappa particles : these are self duplicating cytoplasmic particles found in Paramecium  a urelia . These particles make the animal killer when present in sufficient number.  The kappa particles can be retained one in those individuals which possess a dominant gene K (having recessive allele K) in nucleus .  Cross between killer and sensitive strain  Conjugation takes place for less time : when conjugation takes place for less than three minutes, only nuclear exchange takes place. Formation of cytoplasmic bridge doesn't takes place. After conjugation each race produces its own type.  Conjugation takes place for longer time : When conjugation
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