Economical importance of bryophytes

-
ECOLOGICAL IMPORTANCE OF BRYOPHYTES Mosses and Bryophytes are the first organiasms to colonise rocks. They colonise rock by acidic secretion. This acidic secretion is due to the death of mosses. When the rock is decomposed it helps in soil formation. Therefore New soils are formed. The soil act as binders.  It prevent soil erosion. The water retention capacity of the soil is high ie, water holding capacity of the soil is high.  This reduces surface water run-off which prevent soil erosion. Bryophyte helps in the recycling of nutrients. ECONOMICAL IMPORTANCE OF BRYOPHYTES. 1) SPHAGNUM Sphagnum has high absorptive power with antiseptic property. This can be used to replace cotton in bandages. 2) MERCHANTIA   Mercahntia cures pulmonary tuberculosisand affliction (pain) in liver. Antibiotic substances are also extracted from bryophytes. it also acts as antiseptic, and as preservative POLYTRICHUM Polytrichum dissolove stone in kidney and in gall bladder. 3) IN RESEARCH It is used in the fie
1 comment

Mechanism of enzyme action , active sites, interactions, enzyme specificity, lowering of activation energy, notes

-
Mechanism of enzyme action

      The cellular environment normally does not favour a chemical reaction as the biological molecules are quite stable in aqueous environment in the cell at fixed temp and pH. The activation of substrate is prerequisite to overcome the transition state and to proceed the reaction in desire direction.the activation of the substrate is done by the enzyme. How the enzyme decreases the activation energy ,It will be discussed below.

  Active sites

      The enzymes have a ability to bring the substrate closer and in suitable orientation so as to favour the formation of ES ( enzyme substrate complex ) , the substrate binds to the enzyme at specific place or site called active sites.it is so designed that it will occupy by only the selected molecules, these sites have specific amino acid residues which establish covalent links with the substrate, this links provides the formation of transition state and hence lower the activation energy.each enzyme have different shapes of active sites which depends on the number and type of amino acid involved in binding with substrate and nature of the cofactors. Active site is a 3 D cleft and is a small part of the enzyme.

Binding of enzyme and substrate by multiple interactions

     The amino acids of the enzyme binds to the substrate by a number of noncovalent  interactions such as vanderwal force , hydrogen bonds, and hydrophobic interactions . since the hydrogen bonds are formed in the definite direction ( possible when the substrate have bind forming part in the appropriate position and direction) ,it also a factor of specificity of the enzyme.

Specificity of the enzyme
 
     The bonding of a enzyme and the substrate is very specific , the active site have unique geometry and is complementary to the geometry of the substrate molecule, some enzymes have absolute specificity for only one enzyme while others react with more than one substrates with the same functional groups. The enzyme catalysed a chemical reaction at a particular chemical bond regardless of others structural features.two theories are available to explain this specificity.
i. Lock and key theory
ii. Induced fit theory.

 How enzyme lower the activation energy
     We know that the enzyme enhance the rate of reaction by lowering the activation energy.dor this purpose some amount of energy must be needed ,where dose the energy come from ?
          
        The amino acids residues of enzyme at active sites interact with the substrate molecules by some weak and strong interactions , weak interactions initiate the bonding between the substrate and the active site .in the process the substrate reaches a transition state ., which is the highest energy state . the formation of each such weak interactions releses some free energy which enhances the total energy of the enzyme- substrate complex and stabilised it . the free energy release is called binding energy which helps the enzyme- substrate complex to overcome the barrier and to proceed the reaction in foreward direction. Thus the binding energy is the source of energy used by enzyme to lower the activation energy.

All the best.....

Comments

Post a Comment

Popular posts from this blog

Cell structure and cell wall of algae notes

-
Image
CELL STRUCTURE  CELL WALL FLAGELLA CELL STRUCTURE   On the basis of their organization algal cell maybe differentiate into prokaryotic, mesokaryotic, and Eukaryotic. Prokaryotic are primitive found in Cyanophycean algae characterised by absence of membrane bound organelles, absence of basic protein called histones in DNA.                A Eukaryotic cell have a well organized nucleus and membrane bound organelles.                Mesokaryotic cell has a nuclear membrane and chromosomes(Eukaryotic characters), basic proteins are absent and nucleus division like prokaryotic type (prokaryotic characters). Fou8 in members of Dynophyceae.  1.CELL WALL       Most of the non motile unicellular and multicellular algae possess a typical cellulosic cell wall of non living matter out side the cytoplasmic membrane. It composed of pure or mixed carbohydrate ( cellulose, mucilage, pectin etc.) and substances like alginic acids, fucoidin,, fucin and hemicellulose are present in brown algae
Read more

what is Haplodiplontic life cycle ( triphasic)

-
Image
Triphasic life cycle.       In triphasic life cycle there is a succession of there generation ie may be two haploid generations and one diploid generation or one haploid generation with two diploid generations.it is of following types ie ,   I.Haplobiontic type ( 2 haploid + 1 diploid)         In some rhodophyceae like Batrachospermum two well developed haploid phase are present and the diploid phase is represented by only zygote.                 The haploid plant body bears sex organs ( spermatogonia, carpogonia ) haploid gametes ( sperm and egg)  are formed in these sex organs,a diploid zygote is formed by the fusion of two gametes.the nucleus of the zygote divides meiotically to form four haploid carpogonia ,  they later develop into carposporophyte  generation ( a haploid generation) . the carposporophyte bears carpospores , after liberation carpospores are germinate into heterogeneous chantransia stage ( resting stage) , after this stage a new gametophytic
Read more