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Life processes

life processes

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Life processes

What are life processes ?Life processes are the basic functions

performed by living organisms to maintain their life on this Earth.

Generally these are the life processes that are basic and common in all living organisms-

1. Nutrition2. Respiration3. Transportation4. Excretion

nutrition The process of taking in food and utilising it is called

nutrition . It’s the process in which food is obtained in order to

utilise it to provide energy for performing various metabolic activities of the organism .

The term nutrition comes from nutrient . A nutrient is an inorganic or organic substance required for the maintenance of life and survival of a living organism .

A nutrient can be defined as a substance which an organism obtains from its surroundings and uses it as a source of energy or for biosynthesis of its body constituents .

Types of nutrition There are two types of nutritional modes-autotrophic and

heterotrophic . Autotrophic nutrition means that simple inorganic

substances are taken in and used to synthesize organic molecules. Energy is needed to achieve this. In photo-autotrophic nutrition light is the energy source. In most instances the light source is solar energy, the process being photosynthesis.

Heterotrophic nutrition is nutrition obtained by digesting organic compounds. Animals, fungi, many prokaryotes and protoctists are unable to synthesize organic compounds to use as food. They are known as heterotrophs. Heterotrophic organisms have to acquire and take in all the organic substances they need to survive

.

Autotrophic nutrition The green plants have an autotrophic mode of

nutrition . The autotrophic bacteria also obtain their food by the autotrophic mode of nutrition.

The autotrophic organisms contain the green pigment called chlorophyll which is able to trap the solar energy. Chlorophyll is present in chloroplasts . This trapped sunlight is utilised by the autotrophs to make food by combining inorganic materials like CO₂ and H₂O present in the environment by the process of photosynthesis .

There are other pigments that help in photosynthesis . Facuxanthin and carotenoids.

autotrophic nutritionIn this there is a process photosynthesis. Photosynthesis is a process used by plants and other organisms to convert light energy, normally from the Sun, into chemical energy that can be later released to fuel the organisms' activities.In photosynthesis chlorophyll,sunlight,water and carbon dioxide are needed.

Generally there are three processes-1.Absorption of light energy by chlorophyll.2.Conversion of light energy into chemical energy and splitting of water into hydrogen and oxygen.3.Reduction of carbon dioxide to carbohydrates. 6CO₂+12H₂OC₆H₁₂O₆+6O₂+6H₂O

Heterotrophic nutrition There are three types of heterotrophic nutrition-1. Holozoic2. Parasitic3. Saprophytic Holozoic nutrition is a method of nutrition that

involves the ingestion of liquid or solid organic material, digestion, absorption and assimilation of it to utilize it. It includes taking in the complex substances and converting them into simpler forms.

Heterotrophic nutrition Parasitic nutrition is a mode of heterotrophic

nutrition where an organism (known as a parasite) lives on the body surface or inside the body of another type of organism (known as a host). The parasite obtains nutrition directly from the body of the host.

Saprotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of dead or decayed organic matter. It occurs in saprotrophs or heterotrophs, and is most often associated with fungi (for example Mucor and Rhizobium) and soil bacteria.

Human digestive system In the human digestive system, the process of

digestion has many stages, the first of which starts in the mouth (oral cavity). Digestion involves the breakdown of food into smaller and smaller components which can be absorbed and assimilated into the body. The secretion of saliva helps to produce a amylase which can be swallowed to pass down the oesophagus and into the stomach .

Buccal cavity When we eat food then in our mouth then we take a

complex food which has to be broken down into simpler ones . In our mouth there is a gland salivary gland which releases salivary amylase that breaks down `starch into simple sugar .

Teeth helps in grinding and chewing of food . The molars are the largest of the teeth. They have a large flat biting surface. The function of the molars is to chew, crush and grind food. There are eight molars in the primary dentition and twelve in the permanent dentition.

Buccal cavity Premolar teeth are between the canine front teeth

and thetransition between the tearing function of the canines and the molars. These are transitional teeth; teeth that grinding function of the molars.

Incisors are the eight teeth in the front and center of your mouth (four on top and four on bottom). These are the teeth that is used to take bites of food.

Canine is used for holding, grasping, and tearing food.

oesophagus The or oesophagus, commonly known as the

food pipe or gullet, is an organ in vertebrates which consists of a fibro muscular tube through which food passes, aided by peristaltic contractions, from the pharynx to the stomach. In humans, the esophagus is usually 18–25 centimeters (cm) long. During swallowing the epiglottis tilts backwards to prevent food from going down the larynx .The esophagus travels behind the trachea and heart, passes through the diaphragm and empties into the cardiac of the stomach.

stomach In stomach there are gastric juices released to digest

food Firstly , mucus is released so that it protects inner

lining of stomach . It makes a layer which is protective against acid.

Then , hydrochloric acid is released to purify the food . The food we eat can have bacteria in it . Hydrochloric acid kills the bacteria.

Then pepsin is released which breaks down protein to its simpler form peptones

Small intestine The small intestine is where most chemical

digestion takes place. Many of the digestive enzymes that act in the small intestine are secreted by the pancreas and enter the small intestine via the pancreatic duct. Pancreatic enzymes and bile from the gallbladder enter the small intestine . Pancreatic juice helps to digest protein by trypsin and fats by lipase . Bile helps to digest fats .

Large intestineThe large intestine, also called the

colon or the large bowel, is the last part of the digestive system in vertebrates. Water is absorbed here and the remaining waste material is stored as feces before being removed by defecation.

respiration Respiration is defined as the transport of oxygen from the

outside air to the cells within tissues, and the transport of carbon dioxide in the opposite direction.

There are two types of respiration- 1. Cellular respiration -Cellular respiration is the set of

metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products.

2.Breathing -Breathing is the process that moves air in and out of the lungs, or oxygen through other breathing organs such as gills. For organisms with lungs, breathing is also called ventilation, which includes both inhalation and exhalation.

Mechanism of breathing in human beings There are generally three processes that take place

when there is breakdown of energy-1. Aerobic respiration-firstly there is breakdown of

glucose into a three carbon molecule called pyruvate .aerobic respiration takes place in mitochondria. The process in which glucose is converted into CO2 and H2O in the presence of oxygen, releasing large amounts of ATP. This process includes the Krebs cycle.

respiration

1. Anaerobic respiration-after the breakdown of glucose into pyruvate there is anaerobic respiration , in which lactic acid and less amount of energy is released .this type of respiration takes place generally in our muscles when we need a large amount of energy . It results in cramps . Cramps can be removed by a hot water bath .

2. Anaerobic respiration in yeast-yeast perspires anaerobically in which ethanol , carbon dioxide and a very less amount of energy is released .

respiration The passage of air into the lungs to supply the body

with oxygen is known as inhalation, and the passage of air out of the lungs to expel carbon dioxide is known as exhalation; this process is collectively called breathing or ventilation. In humans and other mammals, the anatomical features of the respiratory system include trachea, bronchi, bronchioles, lungs, and diaphragm. Molecules of oxygen and carbon dioxide are passively exchanged, by diffusion, between the gaseous external environment and the blood. This exchange process occurs in the alveoli air sacs in the lungs.

respiration In human beings air is taken into the body

through the nostrils is filtered by fine hairs that line the passage . The passage is also lined with mucus which helps in this process .

From nostrils the filtered hair passes through the throat which consists of rings of cartilage which ensures that there is no collapse between air passage.

Alveoli-alveoli is the balloon like structure where gaseous exchange takes place. When inside there is more pressure then oxygen diffuses in . And when inside pressure is less then carbon dioxide diffuses out

transportation The circulatory system, also called the cardiovascular

system, is an organ system that permits blood to circulate and transport nutrients (such as amino acids and electrolytes), oxygen, carbon dioxide, hormones, and blood cells to and from the cells in the body to provide nourishment and help in fighting diseases, stabilize temperature

Mechanism of Transportation in human beings There is a muscular organ called heart which plays a

major role in transportation in every animal . Because both carbon dioxide and oxygen has to be

transported , the heart has four different chambers separated by valves .

Oxygen rich blood is received by the left atrium . The left atrium is relaxed when it is receiving blood . It contracts when it is passing blood to left ventricle .

heart The deoxygenated blood is received by right atrium .

It relaxes when its receiving blood and contracts when it passes blood to right ventricle .

Ventricles have thicker walls than artery . Left ventricle has more thick walls because it has to pump blood all over body and right ventricle has thinner walls as compared to the left ventricle because it has to pump blood only to lungs so it needs less pressure .

BLOOD VESSELS Arteries-these are the blood vessels which carry

blood from heart to other parts of the body. Aorta is the largest artery . These have thicker walls . These blood vessels are deep inside the body .

Veins – these are the blood vessels that take blood from all other organs to heart . These have thinner walls as compared to arteries . These are visible sometimes because they are on the upper layer of the body .

Capillaries – these are very fine blood vessels , which connect the arteries and veins . They form a network of blood vessels all over the body .

blood Blood is a bodily fluid in animals that delivers

necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells.

Blood is a connective fluid tissue. There are four components of blood-

1. RBC2. WBC3. Platelets4. Plasma

Components of blood When we are injured then white blood corpuscles

fight the germs that enter our body when we get injured .

Platelets helps in clotting of blood . Whenever we are injured and there is bleeding then platelets forms web so that blood does not flow.

Blood plasma is the pale yellow liquid component of blood that normally holds the blood cells in whole blood in suspension; this makes plasma the extracellular matrix of blood cells. It makes up about 55% of the body's total blood volume.

Transportation in plants

In plants there is transportation of both water and food .

Water in plant is conducted due to xylem.at the roots cell in contact with the soil actively take up ions. This creates a difference in the concentration of these ions between the root and the soil. Water therefore moves into the root from the soil to eliminate this difference .

Food in plant is transported by the tissue phloem. When the leaves prepare food then phloem transports food in whole plant . Food is specially delivered to those parts which are growing .

excretion The excretory system is a passive biological system

that removes excess, unnecessary materials from the body fluids of an organism, so as to help maintain internal chemical homeostasis and prevent damage to the body. The dual function of excretory systems is the elimination of the waste products of metabolism and to drain the body of used up and broken down components in a liquid and gaseous state. In humans and other amniotes (mammals, birds and reptiles) most of these substances leave the body as urine and to some degree exhalation, mammals also expel them through sweating.

Function of kidney in excretion Humans have two kidneys and each kidney is supplied

with blood from the renal artery. The kidneys remove from the blood the nitrogenous wastes such as urea, as well as salts and excess water, and excrete them in the form of urine. This is done with the help of millions of nephrons present in the kidney. The filtrated blood is carried away from the kidneys by the renal vein . The urine from the kidney is collected by the ureter, one from each kidney, and is passed to the urinary bladder. The urinary bladder collects and stores the urine until urination. The urine collected in the bladder is passed into the external environment from the body through an opening called the urethra.

How is urea produced? Within the kidney, blood first passes through the

afferent artery to the capillary formation called a glomerulus and is collected in the Bowman's capsule - found in the liver, which filters the blood from its contents—primarily food and wastes. After the filtration process, the blood then returns to collect the food nutrients it needs, while the wastes pass into the collecting duct, to the renal pelvis, and to the ureter, and are then secreted out of the body via the urinary bladder.

Excretion in plants Plants produce carbon dioxide and water as

respiratory waste products. In green plants, the carbon dioxide released during respiration gets utilized during photosynthesis. Oxygen can be thought of as a waste product generated during photosynthesis, and exits through stomata, root cell walls, and other routes. Other waste materials that are exuded by some plants — resin, saps, latex, etc. are forced from the interior of the plant by hydrostatic pressures inside the plant and by absorptive forces of plant cells. Plants also excrete some waste substances into the soil around them

Name – Anushka SinghClass - 10-ERoll number-03