CHAPTER-6 LIFE PROCESSES

                          CHAPTER-6

                   LIFE   PROCESSES

Introduction

Organisms need material from outside in order to grow, develop and synthesize proteins and other substances needed by our body. For this, nutrition is important in our body. So, we can define nutrition as :

Catabolic process

Catabolic processes include breakdown processes.

Anabolic process

Anabolic process means synthesis processes.

The food that we eat has nutrients in it which provide energy.

Types of nutrients

Different types of nutrients are :

1. Carbohydrates
2. Vitamins
3. Proteins
4. Fats
5. Minerals 

Nutrition

 •   Process of obtaining nutrients from the environment i.e. intake of food and then its digestion in the body.

Types of nutrition

 i.  Autotrophic Nutrition

 ii. Heterotrophic Nutrition

Autotrophic nutrition

    •   Synthesis of food by photosynthesis- ‘photo’ means light and ‘synthesis’ means production. It is the production of food with the help of sunlight.

    •   Photosynthesis equation-

          6CO2+6H2O give C6H12O6+6O2

    •   Events of photosynthesis are as follows: Absorption of light energy chlorophyll which is the green pigment and gives energy for activation of reaction. Then the splitting of water into its constituent’s hydrogen and oxygen leading to the Synthesis of ATP and NADPH2 and finally reduction of CO2 to carbohydrates.

Heterotrophic nutrition

    •   Generally take up energy from plants and animals by using them as food.

    •   Mostly of three types—holozoic, parasitic, and saprophytic.

    •   Digestion- mechanical and chemical reduction of ingested nutrients which can be then converted to energy for use.

    •   Human digestive system- consists of the long alimentary canal that includes mouth, pharynx, oesophagus, stomach, small intestine, large intestine, rectum and anus.

    •   Organs for assistance- pancreas, liver.

Nutrition in humans:

nutrition in human

Respiration

    •   It is controlled by enzymes and energy is released from the breakdown of organic substances. It is of two types that are aerobic and anaerobic.

Aerobic respiration

    •   Oxidation of food materials by oxygen

    •   Produces 36 ATP

    •   The steps followed in cellular respiration

Respiration in Human Beings

Human respiratory system starts consists of nostrils, nasal cavity, pharynx, trachea, bronchi, bronchioles and then lungs. In lungs, alveoli are present, where exchange between the oxygen and carbon-dioxide takes place.

Transportation

First and foremost things, a liquid medium is required always for transportation.

Transportation in humans

    •   Double circulation occurs in human beings i.e. the blood goes through the heart twice during each cardiac               cycle.

    •    Blood and lymph are both involved in transportation

    •   Components of blood are RBCs, WBCs, platelets, and plasma.

    •   Three types of blood vessels are arteries, veins and capillaries.

    •   Arteries carry oxygenated blood in them, except one that is pulmonary artery

    •   Veins carry deoxygenated blood in them, except pulmonary vein

    •   The Right side of the heart gets deoxygenated blood from different cells of the body

        •   The Left side of the heart receives oxygenated blood from lungs.