CARBOHYDRATES :: part 1

CARBOHYDRATES 

-          Carbohydrates are organic compounds that have a molecular formula Cx(H2O)y.

-          These perform vital roles in living organisms.

-          A monosaccharide is the simplest carbohydrates.

-          Carbohydrates can be classified into 4 groups based upon the no. of they have.

o   Monosaccharide

o   Disaccharide

o   Oligosaccharide

o   Polysaccharide.

-          Carbohydrates are of great importance in organisms.

-          Starch (a polysaccharide) serves as an energy store in plants.

-          Cellulose and lignin (polysaccharide) make the plant cell wall.

-          Glucose (monosaccharide) is used for the production of energy in our body.

-          Sucrose (a disaccharide) is called the cane sugar. 

TRILOBITES

                          What are TRILOBITES???

Trilobites were remarkable hard-shelled, segmented creatures that existed over 300 million years ago in the earth’s ancient seas. They became extinct before dinosaurs even came into existence and are one of the most important creatures of the Palaeozoic age.  Though the biggest of the trilobites was about 18 inches long, they were the largest creatures in the Cambrian seas- in fact, the Cambrian period is known as the age of the trilobites.

The trilobites were arthropods, and were distantly related to crabs. Their bodies were divided lengthwise into three lobes or segments, and covered with a though armoured skin. They moved about at the bottom of the sea using limbs that projected from each segment of their bodies.

Some trilobites crawled along the sea floor, some swan, and others drifted with ocean currents. The different trilobite’s species probably had different diets. Some were herbivores and ate only plants, some were scavengers, and ate carrion. When they sensed danger, they would roll up into a ball, or burrow into the sea floor.

Trilobites are special because their fossils are useful for dating rocks, since they can be found in rocks of all ages all over the world.  

            

GROWTH CURVE

 GROWTH CURVE

Growth curve is a plot between cell mass and fermentation time in a fermentation reaction. The significance of this curve is that it shows the increase in the cell mass with respect to the time of the fermentation reaction. Growth curve is drawn when an inoculum (initial mass of required microbes) is added to the nutrient media in the fermentor.

Growth curve can be divided into 4 phases:-

-          Lag phase

-          Log/exponential phase

-          Stationary phase

-          Decline/ death phase

LAG PHASE:-

-          In this phase the inoculum is added.

-          Whenever a microbe is added to a nutrient medium, the microbes do not consume the nutrients in the medium and grow at the very beginning, but every microbe need some time to adjust itself to the new environment.

-          It is the lag phase in which these microbes adjust themselves to the environment.

-          Hence there is absolutely no increase in the cell mass in this phase.

-          Lag phase ends as microbes adjust themselves to the external environment.

LOG/EXPONENTIAL PHASE:-

-          In this phase microbes are completely ready to consume the nutrients from the medium and reproduce.

-          Microbes reproduce exponentially (1 to 2....... 2 to 4 ....... 4 to 8 and so on).

-          Hence in this phase there is a drastic increase in the cell mass, the reaches a maximum point.

-          In this phase the cell birth > cell death.

-          In the lag phase microbes produce the products of our interest.

-          This phase ends when the nutrients are almost exhausted.

STATIONARY PHASE:-

-          In this phase the microbes compete for nutrients and space.

-          As a result of this stress microbes produce secondary metabolites.

-          Secondary metabolites are of great importance to the pharmaceutical industry.

-          In this phase cell birth = cell death.

-          Hence there is neither increase nor decrease in the cell mass. Hence the graph looks like a plateau.

-          This phase ends when all the nutrients of the medium are exhausted.

DECLINE/DEATH PHASE:-

-          In this phase microbes are deprived of nutrients and start dying.

-          So we can say that cell birth < cell death.

-          Hence there is a sharp fall in the cell mass and in the slope of the graph too.

THE AFRICAN BULL FROG

                        THE AFRICAN BULLFROG

      

The African bullfrog is one of the largest frogs in south america. It measures up to 24 centimeters and may weigh over two kilograms. It has a chubby body with a board head and has olive-greenish colored bumpy skin. This frog eats lots and lots of really big bugs, fish,and mice. It has tooth projections on its lower jaw to restrain struggling prey,and will eat prey much anything that will fit in its mouth. The males of this species are known to give nasty bites,      so be careful around them!!!!!!!!!! 

FERMENTOR

FERMENTOR / BIO-REACTOR

               

Fermantor is a large metallic vessel which has mechanism to adjust optimal temperature, pH, sterility and other growth conditions of specific microorganisms. Large scale industrial production of biological products is done with the help of fermenter. The basic design of fermentor includes a closed vessel with air inlets, agitator and some other required features.

1.    Air inlet / sparger:- some microbes require air(oxygen) for their healthy growth, so sterile air is sent in through sparger. It is placed at the bottom of fermentor.

2.    Agitator / Impeller :- Impeller is a paddle like structure that is connected to a motor. It spins in the broth to maintain a uniform mixture of nutrients and microbes in the broth.

3.    Baffles :-  Baffles are rectangular strips of metal attached to the walls of the fermentor. These help in aeration of the broth and to increase turbulence.

4.    Anti foam :- Continuous aeration and agitation can cause formation of foam.  Foam hinders in proper aeration of microbial broth. Foam can be controlled adding anti foam agents like silica, mustard oil and etc.

5.    pH control :- Every organism need an ideal pH for its survival. Metabolism of microbes can change the pH of the broth, which in turn is harmful for the growth of microbes. Hence a pH meter is used to probe the pH value and buffers are added to stabilize pH .

6.     Temperature control :- Every organism can survive only under certain temperature. Microbes produce heat during their metabolic processes which can be harmful for their growth. Hence the temp of broth is maintained by passing cold water through the water jacket around the fermentor.

7.    Addition port :-This port is a provision made for the addition of inoculum  (the initial mass of microbes added to the broth is called inoculum).

8.    Aseptic conditions:- Fermentation can only be successful if the fermentor and apparatus are sterile. Before fermentation all the apparatus including the nutrient medium are sterilized using steam.

9.    Steam inlet:- Steam is sent into the fermentor to sterilize it. 

10.  Harvest port :- The product of fermentation is retrieved through harvest port.

11.  Nutrient media :- Microorganism require proper nutrition for their proper growth and development. A typical nutrient media must contain a carbon source , nitrogen source and sources of other vital nutrients like phosphorus, magnesium, calcium, vitamins and etc.

APPLICATIONS OF FERMENTOR

-       Used for the production of beverages.

-        Used for the production of organic compounds like ethanol, citric acid and acetic acid.

-       Used for the production of various intra-cellular and extra-cellular proteins.

HUNGRY PLANTS

                                              HUNGRY PLANTS


Sundews are generally small plants that grow in flat rosettes. These leaves bear tentacles that radiate in all directions, each bearing a mucilage, giving  the plant its dewy appearance.Insects are attracted towards the plant by its looks and smell of the leaves and get mired in the sticky dew.The struggling victim stimulates its tentacles to bend and touch it, drawing it closer to the leaf. At the same time glands in the leaf  secretes some powerful digestive enzymes. Sundew absorbs the nutrients from the insect within 24-48 hours. when finished its tentacles release the carcass ready for an another meal. 

INTRODUCTION TO THE CELL

CELL

-          This most basic and living unit of any organism.

-           Cell organelles perform various functions in the cell, as organs and organ systems do in our body.

 CELL MEMBRANE

 -  Cell membranes are semi permeable.

-   These membranes are composed of proteins and phospholipids.

-    FUNCTIONS

                                1- Separates cell organelles from external environment.

                                2- Control the exchange of gases and solutes.

                                3- At times functions as a site for photosynthesis and etc.

4- It carries receptors to which various hormones,   antibiotics and other chemicals may attach   and invite a variety of reaction

 MEMBRANE PROTEINS

-  Different types of proteins occur in different membranes.

- Usually hydrophobic portions of the proteins interact with lipids while hydrophilic aqueous contents of the membrane.

- Other membrane proteins may function as receptors for ligands, electrons carrier.

- Some membrane proteins are glycosylated for cell to cell adhesions.

- They play important rule in the immune response.

-  The structure of a membrane can be explained with a fluid mosaic model.

NUCLEUS

- It is found in all eukaryotic cells.

- It is largest of all cell organelles.

- Nuclear membrane contains pores to allow exchange of substances between nucleus and cytoplasm.

-  Nucleus contains one or more nucleoli, chromatin and gel like nucleoplasm.

- Chromatin is composed of DNA which is compliced with basic proteins called histons.

- DNA and histons are organised into bead like structure called NUCLEOSOMES.

-The loosely coiled chromatins that stain less are called euchromatin and the tightly coiled are called   heterochromatin

CYTOPLASM

-          This is the aqueous substance inside the cell.

-          The solute part of cytoplasm is called cytosol.

-          Cytosol is 90% of water in which ions, salts, sugars, amino acids, fatty acids, nucleotides and gases are dissolved.

-          The nucleus and cytoplasm constitute the protoplasm.

-          Cytoplasm is also the site of many other metabolic pathways.

 ENDOPLASMIC RETICULUM ( ER )

-          It is complex network of membranes running through the cytoplasm of the eukaryotic cells.

-          It consists of flattened membranes called CISTERNAE.

TYPES:-

1.       Rough endoplasmic reticulum (RER)

§  It has ribosomes embedded on the surface of cisternae , making it look rough.

§  It helps in protein synthesis.

§  ER sacs covered with ribosomes are called microsomes.

2.       Smooth endoplasmic reticulum (SER)

§  It does not have ribosomes embedded on it.

§  This helps in lipid synthesis.

§  It is also the site of glycosylation.

RIBOSOMES

-          This is found in plant animal and bacterial cells.

-          Found throughout the cytoplasm in large numbers.

-          This is the site of protein synthesis.

-          Each ribosome consists of two subunits a smaller unit and a larger unit.

-          It consists of equal amount of RNA and protein.

-          RNA found here is called ribosomal RNA (rRNA).

-          TYPES:-

      

1.       70S

§  This type is found only in prokaryotes.

§  It has two subunits 50S and 30S.

§  S stands for Svedberg (unit of sedimentation rate).

2.       80S

§  Found only in eukaryotic cells.

§  The two subunits are 60S and 40S.

GOLGI APPARATUS

-          Found in all eukaryotes.

-          Consists of flattened membrane bound sacs called cisterane.

-          Cisterane is formed by the fusion of vesicles, which bud off from the ER.

-          Site of glycosylation.

-          It synthesizes lysosomes.

-          Packing and moving of organelles in and out if the cell.

LYSOSOMES

                              - These are single membrane organelles.

                            -  Contains hydrolytic enzymes like protease, nuclease and lipase.

MITOCHONDRIA

-          These are elongated organelles bounded by two membranes,

-          Inner membrane is folded and called cristae.

-          Its matrix contains few ribosomes, DNA and phosphate granules.

-          Its matrix site for kerbs cycle.

-          Its site for respiration and ATP synthesis.

-          Cristae is the site for oxidative phosphorylation.

-          It is known as power house of the cell.

PLASTIDS

-          These are found only in plant cells and bounded by two membranes.

-          Types

1)       Chloroplast   - contains chlorophyll and green in clour and carries out photosynthesis.

2)       Chromopast – these are non photosynthetic colored plastids containing red, orange and yellow pigments.

3)       Leucoplasts  -  Colorless plastids and lack pigments. These are modified into food storage sites.

    CYTOSKELETON

     
       -These are fibrous protein structure which exsists in all eukaryatic cells giving them their shape.

                   -Types

1)       Microtubules

-   Un-branched, hollow cylindrical organelles and consists of protein called tubulin.

-  These are responsible for the movement of chromosomes and other organelles such as golgi vesicle.

2)    Micro filaments

-  These are fine protein filaments.

- Made of actin.

- Occur in sheets or bundles just below the all membrane.

                                                        - Involved in endocytosis and exocytosis.