BIOLOGY

Biology-the area of science dealing with living things. It includes biological concepts and process skills, technology and attitudes and values for addressing the needs and problems of society. In recent years, the development of techniques in genetic engineering and increased understanding of the molecular basis of cellular processes have led to the emergence of a new and exciting field of scientific research called biotechnology.

ORGANIC COMPOUNDS- characterized by the presence of carbon.

-Carbohydrates - are made up of carbon, hydrogen, and oxygen (e.g., sugar, starches, and cellulose) atoms. They have the general formula CHOn. Their sizes range from the small simple sugars like glucose and fructose to the large and complex forms like starch and glycogen. Only the simple sugars (monosaccharides) can easily pass across cell membranes. Most carbohydrates serve as energy molecules or energy reserves in living organisms.

Cellulose - gives strength and protection to plant cells.

Lipids - are macromolecules such as fats, oils and waxes. They are made up of carbon, hydrogen, and oxygen. The building blocks used to form fats are fatty acids and glycerol. Some excess food in the body is stored as fats. Lipids that are liquid at room temperature are known as olls. Waxes serves as protective body covering to organisms. They make plant and animal tissues water-resistant.

Proteins - are made up of repeating units of amino acids. They are a component of the muscles and all other tissues. In the form of enzymes, they control the rate of chemical reactions inside the cell. Without the enzymes, such chemical processes hardly occur.

Enzymes - are proteins that act as catalysts (substances that can increase or speed up chemical reaction). Enzymes are specific in their actions. They are not used up in the reaction.

Nucleic Acids - are carriers of hereditary information in living organisms. What an organism looks like, and what it can do, are controlled by nucleic acids.

Vitamins - are substances necessary in very small amount for body growth and activity. They are also needed to prevent certain diseases. Vitamins are organic substances essential to life but not required as energy sources. The sources of most Vitamins are plants and bacteria.

INORGANIC COMPOUNDS

- characterized by the absence of carbon.

Water - is the most abundant inorganic compound. About 65% to 95% of the substances of every living thing is water. It is the medium of transport for food, minerals and other substances in

Carbon dioxide - supplies the carbon found in substances made by living things.

- are chemical elements or compounds occurring naturally. They may come from the soil maybe dissolved in water, or maybe found as salt in seawater. Minerals are absorbed by plant roots in the form of ions.

LIFE FUNCTIONS

- All living things carry out certain activities or functions in order to maintain life.

Nutrition is the process of ingesting and absorbing food to provide the energy for life, promote growth, and repair or replace damages tissues.

Transport involves movement of nutrients water. ions. and other materials into and out of the various cells and tissues of organisms. This process includes absorption of small molecules across cell membranes and secretion of biochemicals such as enzymes, mucous, and hormones. In many species, the circulatory system plays an important role in transport.

Metabolism includes the process by which nutrients and simple molecules are used to form more complex molecules for growth, repair, and reproduction (anabolism). Metabolism also includes the process of breaking down complex molecules to release energy from chemical bonds (catabolism) and to provide small molecules such as simple sugars and amino acids as budding blocks for more complex molecules (anabolism).

An internal balance in all aspects of metabolism and biological function is called homeostasis.

Digestion is a special form of catabolism that breaks food down into smaller molecules and releases energy.

Absorption allows small molecules to pass through cell membranes throughout the body tissues.

This allows for a gas exchange and in some species such as plants and fungi nutrients are obtained Dy absorpuon from son and water.

The behavior of living things is a response to stimuli in the environment. These stimuli may include things such as light, chemical signals, noise, or a change in the seasons.

Excretion- the elmination or waste produels.

Reproduction is the process by which an organism produces offspring either sexually or asexually.

Its main purpose is for the perpetuation of species. It is classified into two types, namely:

1. Asexual - is the reproduction without the use of gametes or sex cells. One parent organism ran reproduce by itself.