Energy relationships

Photosynthesis

Photosynthesis is a very importance reaction for Global let’s how to process photosynthesis from following points

                   •   Choloroplasts as the site of photosynthesis, its fine structure, thylakoids, grana and

                    stroma.

                   •   Pigments associated with absorption of light energy. Absorption spectrum of a pigment.

                    Compare with action spectrum of photosynthesis.

                   •   Mechanism of photosynthesis highlighting following points

                    •   Light reactions

                    •   Dark reactions

                    •   Light reactions

                      

Plant tissues and animal tissues

In multicellular organisms, the cells are organized into tissues, organs & organ systems. Tissue is a group of physically linked cells with common origin specialized for a particular function or functions. We can divide tissues to plant tissues and animal tissues.

Types of plant tissues, their structure & function

                    •   Plant tissues can be classified into two groups

                      •   Simple tissues – mainly one type of cells

                      •   Complex tissues – more than one type of cells

                    •   Simple plant tissues are divided into three groups

                        1. Parenchyma      2. Collenchyma     3. Sclerenchyma

                    •   The structure, function and distribution of simple plant tissues.

                    •   Modified parenchyma cells and their distribution and function

                    •   Complex plant tissues are divided into two groups.

                         1. Xylem               2. Phloem

                    •   Structure, function and distribution of complex plant tissues.

                    •   Observation and identification of  different plant tissues under light microscop

Main types of animal tissues and their characters.

    

Structures and functions of sub cellular components.

As we know all organisms are composed of cells. So it is very important thing to study about the cell.  A cell has sub cellular units. All sub cellular units have special structure and functions. Let’s explore that structure and functions one by one.

Structures and functions of organelles and sub cellular components.

   Cell wall

                          •    Outer envelope of plant cell. Animal cells do not have cell walls

                          •    Made up of cellulose and pectin. Hemicellulose, lignin suberin may also be

                             present.

                          •    May have primary and secondary walls. Explain the chemical components of

                             middle lamella, primary cell wall and secondary cell wall.

                          •    Cell wall has pits through which cytoplasm of adjoining cells join through

                             plasmodesmata.

                          •    Functions of cell wall.

                      •    Plasma membrane

                          •    Outer limit of protoplasm.

                          •    Illustrate the structure of the fluid mosaic model of the plasma membrane,

                             consisting of a bilayer of lipids, integral proteins and peripheral proteins.

                             Movable lipids give the fluidity whereas the arrangement of protein molecules

                             gives the mosaic structure.

                    

                          •    Other membranes in the cell also have the same structure.

                          •   Dynamic boundary of cell.

                             •   Permits the entry of water, ions and certain organic molecules.

                             •   Regulates the exit of waste materials.

                             •   Maintains an osmotic balance within the cell.

                             •   Receives information through receptors and transmit signals to co-ordinate

                                activities between cells.

Cells and cellular organization

 Cell theory.

All organisms are composed of cells, some of a single cell some of many cells. Recall the hierarchy of life, the levels of organization mentioned earlier. The basic  unit which can be called “living” is the cell, which may form a single celled organism (e.g.,  Chlamydomonas , Yeast) or a multicellular plant or animal. The cell is the basic structural and functional unit of life. The level of organization of matter represented by a cell shows all the characteristics of life. Any stage below level of a cell cannot be considered living, whether it is a single celled organism or multicellular  plant or an animal.

History and presentation of Cell theory

•    Robert Hooke (1663), while trying to understand why, cork which is a solid substance can float, examined thin slices using a microscope and found that they are      made up of ‘pores’ and coined the term ‘cells’ to describe the pores.

•    Anton Van Leeuwenhook (1650), a contemporary of  Robert Hooke was the first to describe and record  living single celled organisms,  Euglena  & bacteria

•    Matthias Schleiden (1831), a botanist, studying plant tissues concluded that all plants are made up of cells.

 •    Theodore Schwann (1839), a zoologist and Shleiden (1832), concluded that animal tissues are  also made up of cells.

•    Schleiden and Schwann presented the  ‘Cell Theory’ which included the following.

The main organic compounds of organisms

We can find four major organic compounds  in organisms. That major organic compounds have basic chemical nature and functions. We will study them one by one.

The major organic compounds that found in organisms are,

                    •    Carbohydrates

                    •    Lipids

                    •    Proteins

                    •    Nucleic acids

 These  major organic compounds considered as major biological molecules.

  Carbohydrates

                    •   Most abundant organic matter on earth

                    •   The substances that we know as sugars and flour in day-to-day life are examples

                    •   Major elemental composition is C,H,O

                    •   General formula C_x(H₂O)_y - Hydrates of carbon contains the same proportions of

                         H:O (2:1)   found in water

                    •   Monosaccharides, disaccharides and polysaccharides are the three main classes

                         of  carbohydrates                                    

             Monosaccharides

                      •   Name monosaccharides  according to the number of C atoms as; Triose

                          (3C ) e.g. Glyceraldehyde, Tetrose (4C)  e.g. Erythrose - rare in nature,

                          Pentose (5C)  e.g.Ribose,  Ribulose, Hexose(6C) e.g. glucose, fructose, galactose.

                      •   All Monosaccharides are reducing sugars  

                      

             Disaccharides

                      •  Maltose, Lactose are reducing sugars, Sucrose is not a reducing sugar.

             Polysaccharides

                       •     Polysaccharides structured as, 1-4 glycosidic bonds and 1-6

                             glycosidic bonds. Straight chains and branched chain structure. Basic

                             structure and functions of starch, glycogen and cellulose.  Amylase

                             activity on starch. Inulin as an example of  another polysaccharide and

                             hemicellulose, pectin and chitin as important polysaccharide derivatives  

                               

    

Importance of water for life.

As you know, water is essential thing for our daily life. We can't live without water. Why water importance for every living beings? be course it is the most abundant inorganic compound in living matter.
We use water for drink,food process, cleans, and many more works. lets explore functions of water in organisms.

The main functions of water in organisms

We can see 4 main functions of water in organisms. they are,

1. Component of  protoplasm
2. Solvent
3. Reactant
4. Maintaining turgidity

Other than, We can find many functions of water. I created a table with that functions. that table includes water's property role and examples. you can study it easily.

Characteristics and variations of Living organisms

Do you can identify a Living organisms?..yes.. all  living organisms can identify another living organisms. but scientist couldn't give a one sentence or paragraph to describe living organisms. so,We have to learn variations and Characteristics to describe living organisms. lets explore variations and Characteristics of living organisms.

Variations of Living organisms

Living organisms show a wide range of variation in size, shape, form and distribution
examples:
Size – Bacteria – 0.25   – 2   μ   to  Giant Sequoia (Giant Red Wood)– 100 m
Shape – Organisms are diverse in shape
Form – a cellular , unicellular, multi cellular
Distribution – Terrestrial, aquatic, arboreal, aerial

 Characteristics of living organisms

We can see following  Characteristics from living organisms study them carefully.

                   (1)   Order and organization
                       From molecular level to biosphere there is an order and organization in organisms to
                       perform their biological activities efficiently

                 (2)   Metabolism
                       The sum of all chemical activities taking place in an organism is  its metabolism. It
                       includes catabolic reactions and anabolic reactions.

                 (3)   Growth and development
                       All organisms begin their life as a single cell. During growth an irreversible increase
                       in dry mass occurs, which is characterized only by the living. Growth and
                       development are two consequent processes that happen in the life span of organisms.

Introduction to Biology and “Biology College”

You are warmly welcome to "Biology College". first, I’ll say about me. I'm a science student studying in biological science. I'm like to do researches and practicals in biology. so I thought to share my knowledge via my Biology College blog. if you are prefer to biology I'm sure you will like to this blog.

Let’s see about biology. Biology is a very beautiful and interesting subject that studying about the life. This subject divide to many sections as example microbiology, biochemistry, astrobiology...ect: As you know biology very useful to our daily life. It helps to us to continue a healthy life. Do you know the importance and main targets from biology? lets collect some of them.

 The importance and main targets of biology

•   Understanding biological diversity :

                 There has been life on earth for over 3.5 billion years. We should understand that there are around 30 million species of animals and plants in the world. There is a dynamic relationship between the world of life and the inanimate world.

 •   Understanding the human body and its functions:

                 We should be able to appreciate the organization of the human body, how systems within the body are interconnected and the way structure is related to function.

 •   Management of natural resources and environment:

                 The natural resources are limited and with the current increase in

                 growth of human population there is a threat of depletion of natural resources. Destruction of Ozone layer in the atmosphere, acid rain, global warming caused by increasing concentrations of CO  in the atmosphere, pollution of rivers and underground water supplies leading to a dearth in drinking water in the future etc, are some of the results.