Life Processes Class 10 Notes

Chemical Reactions and Equations Class 10 Notes


These life processes class 10 notes cover all the topics in this used as per the CBSE prescribed textbook. These biology class 10 life processes notes will help you revise the study material quickly and prepare for your exams.

What Are Life Processes?

Life processes refer to the various processes required for the maintenance of life. Because these maintenance procedures are required to prevent damage and breakdown, energy is needed for them.

This energy comes from somewhere other than the personal organism’s body. Therefore, a process must move an energy source from the outside of the organism’s body to the inside. This process is known as nutrition.

Many of these food sources are carbon-based since life on the planet is centred on carbon-based molecules. Different types of organisms can derive power via various nutritional processes based on the complexity of these carbon sources.

Organisms are classified into two types.

  • Autotrophic 
  • Heterotrophic 

What Is the Source of Food for Living Organisms?

All organisms share the general requirement for energy and materials, but it is met in various ways. Some organisms consume simple food materials derived from inorganic sources, such as carbon dioxide and water. Green plants and some bacteria are examples of autotrophs. Other organisms make use of complicated substances.

Before they can be used for body maintenance and growth, these complex substances must be broken down into simpler ones. Organisms employ bio-catalysts known as enzymes to make it happen. Thus, the survival of heterotrophs is dependent on autotrophs, either directly or indirectly. Animals and fungi are examples of heterotrophic organisms.

Nutrition Biology Class 10 Notes

Nutrition is the process of obtaining nutrients from the environment. It is the process by which an organism consumes, digests, absorbs, transports, and utilises nutrients and disposes of its byproducts.

Autotrophic Nutrition: The autotrophic organism’s needs for carbon and energy are met via photosynthesis. It is the method by which autotrophs absorb materials from the environment and transform them into forms of energy that may be stored. This substance is consumed as carbon dioxide and water, which, when exposed to sunshine and chlorophyll, are transformed into carbs. The plant uses carbohydrates to get its energy from them.

Starch, which serves as the plant’s internal energy reserve and is used as and when necessary, is created from the carbs that are not immediately consumed.

During the process, the below events occur:

  • Light energy is absorbed by chlorophyll 
  • Splitting of water molecules into hydrogen and oxygen and the transformation of light energy into chemical energy
  • Carbon dioxide is reduced to carbohydrates

Stomata are tiny spares found on the leaves. Stomata are responsible for gas exchange between the plant and the atmosphere. Two semi-circular guard cells surround each stoma. The guard cells’ role in pore opening and closure is crucial. When water enters the guard cells, they swell, which opens the stomatal pore. Similarly, if the guard cells contract, the pore closes.

Heterotrophic Nutrition: A type of nutrition in which organisms obtain nourishment (nutrients) from those other living organisms. Energy is derived from the intake and digestion of organic substances, typically plant or animal tissue, in heterotrophic nutrition.

Nutrition in Amoeba

Amoeba shows a holozoic mode of nutrition. It ingests food by temporarily extending the cell surface into the shape of fingers that fuse over the food particle to form a food vacuole. Complex compounds are broken down into simpler ones inside the food vacuole, which then diffuse into the cytoplasm. The cell’s surface is where the leftover undigested matter is ejected out.

Nutrition in Paramoecium

The cell in Paramoecium, another unicellular organism, has a distinct form, and food is taken in at a certain location. The action of cilia, which cover the whole surface of the cell, transports food to this location.

Nutrition in Human Beings 

In essentially, the alimentary canal is a long tube that runs from the mouth to the anus. Different locations are specialised to carry out specific tasks. When food enters our bodies, what happens to it? Here, we’ll talk about this process.

Our mouth waters while we eat something. This is not just water but a fluid called saliva, which is secreted by the salivary glands. Because the canal lining is gentle, the food is moistened to ensure a smooth passage. Naturally, the food must be processed to produce particles that are small and have the same texture. This is accomplished by crushing the food with our teeth in order to smooth out the digestive tract. It must be broken down into smaller molecules in order to be consumed from the alimentary canal. This is accomplished with the assistance of biological catalysts known as enzymes. 

Salivary amylase is an enzyme found in saliva that breaks down starch, a complex molecule, into simple sugar. The food is thoroughly mixed with saliva and moved all around the mouth by the muscular tongue while chewing.

The food pipe, also known as the oesophagus, transports the food from the mouth to the stomach. The stomach is a big organ that becomes bigger as food goes in. The muscular stomach walls thoroughly blend the food with additional digestive liquids.

The gastric glands found in the stomach wall are in charge of the stomach’s digestion. These expel mucus, pepsin, an enzyme that digests proteins, and hydrochloric acid. The hydrochloric acid produces an acidic environment that aids the pepsin enzyme’s function. What other purpose do you suppose the acid serves? Under normal circumstances, the mucus shields the stomach’s inner lining from the effects of the acid.

A sphincter muscle controls the amount of food that is released from the stomach into the small intestine. The meal now moves into the small intestine from the stomach. Due to considerable coiling, the longest portion of the alimentary canal can fit into a small area. Depending on each animal’s food, its small intestine length varies. For the cellulose to be absorbed, herbivorous animals consuming grass require a longer small intestine. Carnivores like tigers have shorter small intestines because the meat is easier to digest.

Carbohydrates, proteins, and lipids are completely digested in the small intestine. For this function, it receives pancreatic and liver secretions. For the pancreatic enzymes to work, the acidic food that comes from the stomach must be converted to alkaline. The liver’s bile juice does this in addition to working on lipids.

Large globules of fat are present in the colon, making it challenging for enzymes to break them down. In order to increase the effectiveness of enzyme function, bile salts break them down into smaller globules.

Trypsin, an enzyme for breaking down proteins, and lipase, an enzyme for dissolving emulsified fats, are both found in pancreatic juice, which is secreted by the pancreas. Small intestine walls have glands that release intestinal juice. The enzymes in it ultimately turn fats into fatty acids and glycerol, complex carbs into glucose, and proteins into amino acids.

The intestine’s walls absorb the food that has been digested. Villi are many finger-like extensions that line the interior of the small intestine and increase the surface area available for absorption. Each and every cell in the body receives the absorbed food through a network of blood channels in the villi, where it is used to create new tissues, repair damaged ones, and provide energy.

The large intestine receives unabsorbed food and draws extra water from it through its wall. The anus is used to expel the remaining substance from the body. The anal sphincter controls the escape of this waste material.

Different organisms use food to gain energy in various ways. Some utilise oxygen to totally break down glucose into carbon dioxide and water, while others use other oxygen-free processes. The conversion of glucose, a six-carbon molecule, into pyruvate, a three-carbon molecule, is always the initial step. In the cytoplasm, this process happens. Pyruvate can also be transformed into ethanol and carbon dioxide. It happens in the fermentation of yeast. It’s known as anaerobic respiration when no air (oxygen) is present. In the mitochondria, pyruvate is broken down by utilising oxygen.

Three molecules of carbon dioxide are produced as a result of this reaction, which splits the three-carbon pyruvate molecule. Water is the additional component. This process is known as aerobic respiration because it occurs in the presence of air (oxygen). Compared to the anaerobic phase, the release of energy during this aerobic process is much greater. Our muscle cells’ ability to break down pyruvate occasionally shifts to another pathway when there is insufficient oxygen present. Here, the pyruvate is changed into the three-carbon molecule lactic acid. Cramps are brought on by the accumulation of lactic acid in our muscles during intense exercise.

The energy generated during cellular respiration is promptly put to use in the creation of the molecule ATP, which powers all other cellular processes. These processes include the breakdown of ATP, which produces a fixed quantity of energy that can power the endothermic reactions occurring inside the cell.

Respiration in Human Beings

Respiration is the process by which food is oxidised to release energy. There are two types of respiration: aerobic and anaerobic. Aerobic respiration increases the amount of energy available to the organism.

The energy released during cellular respiration is used right away to create an ATP molecule, which is used to power all other molecules. Cellular activities ATP is broken down in these processes, giving rise to a fixed amount of energy capable of driving endothermic reactions within the cell’s confines. 

The passage is lined with mucus, which aids in this process. After that, the air passes through the throat and into the lungs. There are cartilage rings in the throat that keep the airway from collapsing. The passage is filtered by the fine hairs present in that line passage.

The passage within the lungs becomes smaller and smaller tubes that eventually end in balloon-like structures are known as alveoli (singular–alveolus). The alveoli serve as a surface where gas exchange can occur. The alveolar membranes contain a large network of blood vessels. During the respiratory cycle, when air is required to take in and released from the lungs, the lungs always have a residual amount of air so that oxygen can be absorbed and carbon dioxide can be released.

Transportation in Human Beings Class 10 Notes

Blood is a connective tissue fluid. The cell lines are suspended in plasma, a fluid medium. We need a pumping organ to circulate blood throughout the body.

Our Pump: The Heart

Heart is a muscular organ about the shape of our fist. Because blood must transport both oxygen and carbon dioxide, the heart has distinct chambers to prevent o2-rich blood from mixing with the blood that contains CO2.  The carbon dioxide-rich blood must travel to the lungs in order for the carbon dioxide to be eliminated, and the blood and oxygen from the lungs must return to the heart. This O2-rich blood is then circulated throughout the body.

The thin-walled upper chamber of our heart i.e. left atrium, receives O2-rich blood from the lungs. When this blood is collected, the left atrium relaxes. It then contracts while the following chamber, the left ventricle, loosens, allowing blood to flow to it. The blood is pumped out to the body when the heavily muscled left ventricle contracts. As it relaxes, de-oxygenated blood flows from the body to the upper chamber present on the right, the right atrium. As the right atrium contracts, the right ventricle, the respective lower chamber, dilates. This sends blood to the right side of the heart, which then sends it to the lungs to be oxygenated.

In the lungs, oxygen enters the blood.  This allows for a high-efficiency source of oxygen to the human body. The body temperature of living creatures that do not expend energy for this purpose is affected by the temperature of the environment. This separation allows for a high-efficiency source of oxygen to the human body.

The division between the right and left sides of the heart is helpful in preventing the mixing of oxygenated and deoxygenated blood. Such a division helps the body to receive oxygen very effectively. This is helpful for creatures with high energy requirements, such as birds and mammals, who must constantly expend energy to keep their bodies warm. Animals that don’t expend energy for this purpose have body temperatures that are influenced by the ambient temperature. Like many reptiles and amphibians, these creatures have three chambers in their hearts and can tolerate some blood mixed with oxygenated and deoxygenated blood. Fishes, on the other hand, have hearts with only two chambers; blood is pumped to the gills, where it is oxygenated before travelling directly to the rest of the body. As a result, throughout one cycle of movement through the body, blood in a fish only passes through the heart once. However, in other vertebrates, it passes through the heart twice throughout each cycle and is known as double circulation.

When an artery reaches an organ or tissue, it splits into smaller and fewer vessels. Since blood exits the heart at pressure, the arteries have tight, elastic walls. The smallest vessels, known as capillaries, have one-cell thick walls. Because blood isn’t longer under pressure, they do not require thick walls.

Platelets: They are responsible for maintenance. Naturally, blood loss from the system must be kept to a minimum. Furthermore, leakage would result in pressure loss, lowering the system’s efficiency.

Lymph: This other type of fluid is also used in transportation. This is known as lymph or tissue fluid. Some plasma, proteins, and blood cells escape through the pores in capillary walls into cell walls in the body tissue to form tissue fluid or lymph.

Transportation in Plants Chapter 6 Class 10 Science Notes

Transport mechanisms in plants transport basic materials from the roots and energy reserves from the leaves. These two channels are built as separate networks of conducting tubes. The xylem transports water and minerals that come from the soil first. The other, phloem, carries photosynthetic byproducts from the leaves, where they are produced, to other plant organs.

Transport of Water

The vessels and tracheids of the roots, stems, and leaves are interconnected in xylem tissue to create a continuous system of water-conducting channels that reach all parts of the plant. This means that a column of water is steadily pushed upwards. However, this pressure is unlikely to be sufficient to transport water over the heights seen in plants.

Water loss through to the stomata is modified by water from the xylem vessels in the leaf. The evaporation of molecules of water from a leaf’s cells creates a suction that draws the roots for water. Transpiration aids in the absorption upwards and movement of dissolved water and minerals from the leaves to the roots.

Transport of Food and Other Substances

Unlike xylem transport, which is largely explained by simple physical forces,  phloem translocation is accomplished with the assistance of neighbouring cells. This transport of soluble photosynthesis products is known as translocation, and it takes place in the vascular tissue of the plant. Unlike xylem transport, which is largely explained by simple physical forces, phloem translocation is accomplished with the assistance of neighbouring cells.

Excretion in Human Beings Biology Class 10 Chapter 6 Notes

The human excretory system consists of two kidneys, two ureters, a urinary bladder, and a urethra. The kidneys are in the abdomen, one on each side of the backbone. Urine produced in the kidneys travels through the ureters into the urinary bladder, which is stored until it is expelled via the urethra.

The goal of producing urine is to filter the blood’s waste products. Nitrogenous waste, such as urea or uric acid, is removed from the blood in the kidneys in the same way that CO2 is eliminated from the blood in the lungs. It is not surprising, then, that perhaps the normal filtration unit in the kidneys.

A urinary bladder tube connects the kidneys to the urinary bladder. Urine is stored in the bladder until the expanding bladder pressure causes the urge to pass it out via the urethra. Because the bladder is muscular, it is subjected to nervous control.  Each kidney’s urine then enters the ureter, the tube that joins the kidney to the bladder.

Excretion in Plants 

Method of excretion in animals differs entirely from those used by plants.

One could consider oxygen itself to be a waste product produced during photosynthesis!

We’ve already spoken about how plants utilise both CO2 and oxygen. By transpiring, they can get rid of extra water. Plants make use of the fact that a lot of their tissues are made up of dead cells and that they can even lose certain sections, like leaves, to make other wastes. Cellular vacuoles serve as storage for a variety of plant waste products. Waste materials might be kept in fallen leaves.

Other waste materials, particularly in the ageing xylem, are retained as resins and gums. Additionally, plants excrete some waste materials into the earth surrounding them.


  • Different sorts of movement might be seen as a sign of life.
  • Nutrition, respiration, material transit within the body, and excretion of waste products are all necessary for maintaining life.
  • In autotrophic nutrition, simple inorganic materials from the environment are consumed, while complex, high-energy organic components are synthesised utilising an external energy source, such as the sun. In heterotrophic nutrition, complex food that other species have manufactured is consumed.
  • n In humans, the food consumed is broken down in a number of processes in the alimentary canal before being absorbed in the small intestine and distributed to all body cells.

We hope these biology class 10 life processes notes helped clear your concepts and will help you achieve better grades.