Life Processes

Main concept:

Nutrition in plant ,Nutrition types, Nutrition in human
Respiration in plant, Respiration in human being
Transportation in plant , Transportation in human being
Excretion in plant, Excretion in human being

What are the life processes?

The maintenance function of the living organism must go on even , We are sleep and we are sitting. These works are going on from these all works performing definitely we need energy. This energy come from the outside of the body, which we call food ,to the inside a process called ‘nutrition’. different organisms can uses different kind of ‘nutritional processes’.

For suppose body needs to grow kinds of molecules ,for this the chemical reaction in the body is is necessary oxidizing -reduction reaction takes plays some of the most common chemicals break into molecules. for this many organisms uses uses oxygen source from the out side.t then this oxygen uses break down the food for cellular needs ,we call ‘respiration’ .

Since food and oxygen are taken up at one place in the body of the organisms, while all parts of the body needs them .This situation creates a need for a ‘transportation system’ for carrying food and oxygen from one place to another place in the body.

The waste by the byproducts are needed to be removed from the body and discarded outside by the process, we call ‘excretion’. Multi cellular organisms design a specialized tissue for the excretion will be developed to transport the waste away from the cell to this excretory tissue.

Firstly we would discuss nutrition.

Nutrition

Simply,The process by which an organism takes food and utilizes it,is called Nutrition.Organisms need energy to perform various activities and they need various raw materials for growth and repair of the body.

Modes Of Nutrition

Nutrition In Plants ,Plants are autotrophs .They prepare their own food.
Nutrition In Animals.
Animals are heterotrophs. They depend on plants or others.

Autotrophic nutrition:

An organism prepares its own food from simple inorganic materials like water ,carbon dioxide and other salts in the presence of sunlight is called Autotrophic nutrition .

Autotrophs are obtain energy by using photosynthesis process carbohydrates are utilized for providing energy to the plants.these carbohydrates are stored in the form of starch.which serves as the internal energy reserve to be used as and when required by the plant.similarly some of the energy is stored in our body in the form of glycogen.

This equation for the photosynthesis

Main events in photosynthesis:

Absorption of light energy by chlorophyll
Conversion of light energy to chemical energy and splitting of water molecules into hydrogen and oxygen
Reduction of carbon dioxide to carbohydrates.

These steps occur slowly one after another.

If we observe the picture carefully, the cross section of the leaf under the micro scope.you will notice the small cells in green dots. These green dots are called chloroplast,which contain chlorophyll.

We observe in the next picture tiny pores present on the surface of leaves. Heavy amount of gases exchanging takes place in the leaves through these pores for the purpose of photosynthesis.gases exchanging across the stems roots and leaves.large amount of water lost by the stomata. plants close the pores if does not need.opening and closing the pores by the guard cell.

Heterotrophic nutrition

An organism dependent on other organisms to survive.Organisms that cannot prepare their own food and depend on other organisms are known as heterotrophs. These type of nutrition is known as heterotrophic nutrition

Examples are animals, fungi and bacteria.

Heterotrophic nutrition involves intakes of complex material prepared by other organisms.

How do Organisms obtain their food?

Unicellular/Single-celled organisms - Food is taken up through the entire surface.

Example - Amoeba, Paramecium

But in multicellular organism takes several steps, it may take long time

Example- human beings and animals.

Nutrition in Human beings

The various steps of nutrition in human beings are as follows:

Ingestion:

In human beings, food is ingested through the mouth. The food is put into the mouth

Teeth

Chewing/grinding of food into small pieces ,this process is called Mastication

Tongue

Rolling of food + tasting of food + swallowing/pushing down the food

Salivary glands

secrete saliva + mucus (it is a sticky material)

Esophagus

The slightly digested food in the mouth is swallowed by the tongue and goes down the food pipe called oesophagus.Taking food from mouth to stomach by peristaltic movements

(contraction and expansion of muscles of the esophagus).

Stomach

The stomach is a J-shaped organ present on the left side of the abdomen.Gastric glands present in the stomach secrete gastric juice.The gastric juice contains three substances: Hydrochloric acid, the enzyme pepsin, and mucus.The partially digested and semi liquid form of food (chyme)then goes from the stomach into the small intestine.

Small intestine

The small intestine is the largest part of the alimentary canal, it is the site of the complete digestion of carbohydrates, proteins and fats. Walls of small intestine secrete intestinal enzyme which converts carbohydrates into glucose, fats in fatty acid + glycerol and proteins into amino acids. It has villi (finger projection) which help in the absorption of food into blood

It receives the secretions of the liver and pancreas.The food is acidic which is made alkaline for the pancreatic enzymes to act. The

pancreas secretes pancreatic juice which contains enzymes like trypsin for digesting proteins and lipase for breaking down emulsified fats.

Large intestine

It absorbs excess water and the remaining material is eliminated from

the body through the anus.

Respiration

Respiration is a process by which food is broken down by release of energy.

Respiration are divided into two types:

1. aerobic

2.anaerobic

Types of respiration

Aerobic respiration

It occurs in presence of oxygen

It occurs in mitochondria

More amount of energy released

Finally give water and carbon dioxide

Anaerobic respiration

It occurs in Absence of oxygen
It occurs in cytoplasm.
Less amount of energy released
Finally gives alcohol and lactic acid

Different pathway of breakdown glucose:

The first step is the breakdown of glucose ( six-carbon molecule) into a three-carbon molecule called pyruvate which takes place in the cytoplasm. The pyruvate can be converted into ethanol and carbon dioxide which takes place in yeast during fermentation. Since the process occurs in the absence of air (oxygen), it is called anaerobic respiration. The pyruvate is broken down into a three-carbon pyruvate molecule in the presence of oxygen to give three molecules of carbon dioxide and water. This process takes place in mitochondria. Since this process takes place in the presence of oxygen, it is known as aerobic respiration. Here the pyruvate is converted into lactic acid when there is a lack of oxygen in our muscle cells, which is also a three-carbon molecule. This build-up of lactic acid in our muscles during exercises or running.

The energy released during cellular respiration is immediately used to synthesize a molecule called ATP. ATP is the energy currency of the cell. ATP is broken down giving rise to a fixed amount of energy which can derive the endothermic reactions taking place in the cell The rate of breathing in aquatic organisms is much faster than that seen in terrestrial organisms because the amount of dissolved oxygen is low compared to the amount of oxygen in the air.

Respiratory system in human beings

Nostril

Air is taken into the body.

Nasal passage

It is a channel for airflow through the nose.

Nasal cavity

It is lined with hair and mucous membrane. It warms, moisturizes and filters air before it reaches the lungs.

Pharynx

it contains rings of cartilage which ensure that the air -passage does not collapse.

Larynx

it houses the vocal cords and manipulates pitch and volume, which is essential for phonation. It is also known as the voice box.

Trachea

Pharynx splits into the trachea and esophagus. It connects the larynx (or voice box) to the bronchi of the lungs. It provides airflow to and from the lungs for respiration.

Bronchi

They are the main passageway into the lungs. They are the extension of the windpipe that shuttles air to and from the lungs. The oxygen goes to the lungs and carbon dioxide leaves the lungs through them.

Bronchioles

Bronchi get smaller when they reach closer to the lungs tissues and are called Bronchioles. They are the passageways by which air passes through the nose or mouth to the alveoli of the lungs.

Alveoli

they are smaller tubes which finally terminate in balloon-like structures which are called alveoli. They allow carbon dioxide and oxygen to move between the lungs and the bloodstream.

Blood capillaries

They are the sites of transfer of oxygen and other nutrients from the bloodstream to other tissues in the body. They also collect carbon dioxide and waste materials and return them to the veins.

In human beings, the respiratory pigment is hemoglobin which has a very high affinity for oxygen. This pigment is present in the red blood corpuscles. Carbon dioxide is more

soluble in water than oxygen.

Transportation

The movement of any substance from one place to another is known as transpiration or circulation. Water and nutrients required for all metabolic activities should be transported in the body of plants and animals.

Circulatory system in human beings consists :

heart(pumping organ)
arteries and veins (blood vessels)
blood and lymph(circulatory medium)

Heart

The human heart is about the size of a human fist and is divided into four chambers,namely two ventricles and two atria. The ventricles are the chambers that pump blood and the atrium are the chambers that receive blood. Among which both the right atrium and ventricle make up the “right heart,” and the left atrium and ventricle make up the “left heart.”

The structure of the heart also houses the biggest artery in the body – the aorta.The right and the left region of the heart are separated by a wall of muscle called the septum. The right ventricle pumps the blood to the lungs for re-oxygenation through the pulmonary arteries. The right semilunar valves close and prevent the blood from flowing back into the heart. Then, the oxygenated blood is received by the left atrium from the lungs via the pulmonary veins.

The blood goes only once through the heart in one cardiac cycle is known as single circulation.

eg: fish etc,

The blood goes twice through the heart in one cardiac cycle is known as Double circulation.

eg: human and mammals

Blood vessels

There are different types of blood vessels in our body each carrying out specialized functions. Three types of blood vessels are: Arteries, Veins and Capillaries.

Arteries:

These are thick-walled blood vessels which carry oxygenated blood from the heart to different organs. Pulmonary arteries are exceptions because they carry deoxygenated blood from the heart to lungs, where oxygenation of blood takes place.

Veins:

These are thin-walled blood vessels which carry deoxygenated blood from different organs to the heart, pulmonary veins are exceptions because they carry oxygenated blood from lungs to the heart.Valves are present in veins to prevent backflow of blood.

Capillaries:

These are the blood vessels which have single-celled walls.

Blood

Blood is a connective tissue which is fluid in nature. The solid components of Blood(Blood corpuscles) are:

RBC(Red Blood Cells) - It carries oxygen and carbon dioxide and also contains Haemoglobin which imparts red colour to the blood

WBC(White Blood Cells) - It provides body defence by engulfing the germs and produces antibodies

Blood Platelets - During any injury, it helps in blood clotting

Lymph:

Lymph is similar to blood but RBCs are absent in lymph. Lymph is formed from the fluid which leaks from blood capillaries and goes to the inter-cellular space in the tissues. This fluid is collected through lymph vessels and finally returns to the blood capillaries. Lymph also plays an important role in the immune system. Lymph a yellowish fluids escape from the blood capillaries into the inter-cellular spaces contain less proteins than blood. Lymph flows from the tissues to the heart assisting in transportation and destroying germs.

Transportation in plants

The plant transport systems move energy stores from leaves and raw materials from roots. Both of these pathways are constructed independently through different conducting tubes Xylem moves water and minerals obtained from soil whereas phloem transports products of photosynthesis from leaves to other plant parts

Transport of water

Leaves and stems of the xylem tissue are interconnected forming a continuous system of water-conducting channels reaching all plant parts. water lost through stomata is replaced by water from the xylem vessels in the leaf. Evaporation of water molecules from leaf cells creates a suction, pulling water from xylem cells of the roots.

Transport of food and other substances

The transport of soluble products of photosynthesis is called translocation.

Translocation occurs in the vascular tissue phloem where apart from the transport of products of photosynthesis, it also transports amino acids and other substances which are specially delivered to the storage organs of fruits, roots and seeds and even to the growing organs.

Translocation in phloem can be achieved by utilizing energy, derived from ATP, for instance, transfer of sucrose into phloem tissue.