Life processes class 10 notes

Class 10 - Life Processes Notes

What are Life Processes?

➥ Life processes encompass a set of interconnected activities within an organism that collectively contribute to its repair and maintenance. These crucial processes include Respiration (R), Excretion (E), Nutrition (N), and Transportation (T), forming the acronym RENT.

Nutrients

➥ Nutrients: Groups of food that include proteins, fats, vitamins, and minerals.

➥ Nutrition: The process of taking in and using nutrients like carbohydrates, fats, proteins, minerals, vitamins, and water by an organism.

Modes of Nutrition

⟹There are mainly two types of nutrition:-

Autotrophic Nutrition
- ⟹ Process of Autotrophic Nutrition:
  ➥ 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.
Stomata

➥ Stomata are small openings on the leaf surface that allow gas exchange (CO2 and O2) with the atmosphere.

➥ They enable the evaporation of water from the leaf surface, which helps in transpiration.

➥ Stomata also allow the intake of carbon dioxide and the release of oxygen during photosynthesis.

Heterotrophic Nutrition
- ⟹ Types of Heterotrophic Nutrition:
  - 1. Saprotrophic Nutrition:
    - ➥ The word "sapro" means rotten.
    - ➥ Obtaining food from dead and decaying matter.
    - eg:- Mushroom, yeast, bacteria.....etc.
  - 2. Parasitic Nutrition:
    - ➥ Obtaining food from a host organism without killing it.
    - eg:- Cuscuta (Amarbel), tapeworms, lice.
  - 3. Holozoic Nutrition:
    - ➥ Taking in solid food and digesting it.
    - eg:- Humans and most animals.
    - Types of Holozoic Nutrition:
      1. (i)Herbivores: Animals that eat only plants. eg:- Cow, deer.
      2. (ii) Carnivores: Animals that eat other animals. eg:- Lion, tiger.
      3. (iii) Omnivores: Animals that eat both plants and animals. eg:- Humans, bears.

How Animals Obtain Their Nutrition

⟹ The process of breaking down complex substances of food into simpler substances is called digestion.

Process of Nutrition

➥ Nutrition is the process through which animals obtain and utilize nutrients to sustain their growth, energy, and repair tissues.

Nutrients in Amoeba

➥ Amoeba is a tiny, single-celled organism that gets its nutrients through the following steps:

Nutrition in Amoeba

Ingestion: Amoeba takes in food by surrounding it with its pseudopodia (false feet) and forming a food vacuole.
Digestion: Inside the food vacuole, the food is broken down into smaller, soluble molecules by digestive enzymes.
Absorption: The nutrients from the digested food move into the Amoeba’s cytoplasm. This process is called diffusion. The remaining undigested particles are left behind.
Assimilation: The absorbed nutrients are used to produce energy needed for the Amoeba’s life processes.
Egestion: Undigested food is expelled from the Amoeba by pushing it out through the cell membrane.

Nutrition in Animals

Animals follow these steps for nutrition:

Ingestion: Intake of food by mouth.
Digestion: Breakdown of food into simpler substances.

In Mouth: Food is crushed by teeth, mixed with saliva (salivary juice), and tasted. Saliva starts breaking down starch.
In Oesophagus: Food moves through the oesophagus by peristaltic movement. No digestion occurs here.
In Stomach: The stomach breaks down food with gastric juice. It contains acid and pepsin to digest proteins.
In Small Intestine: The small intestine continues digestion, converting proteins to amino acids, carbohydrates to glucose, and fats to fatty acids and glycerol.
In Liver: The liver makes bile juice to neutralize stomach acid and help digest fats.
In Pancreas: The pancreas releases pancreatic juice, which contains enzymes to digest proteins and fats.

Absorption: Nutrients are absorbed in the small intestine through tiny projections called villi.
Assimilation: The body uses absorbed nutrients for energy and to build and repair tissues.
Egestion: Waste moves to the large intestine, where water is absorbed. The remaining waste is removed from the body through the anus.

Respiration

➥The process by which a living being utilises the food to get energy, is called respiration. Respiration is an oxidation reaction in which carbohydrate is oxidized to produce energy. Mitochondria is the site of respiration and the energy released is stored in the form of ATP (adenosine triphosphate). ATP is stored in mitochondria and is released as per need.

Steps of Respiration

>➥The breakdown of glucose into pyruvate occurs in the cytoplasm. During this process, a glucose molecule, with 6 carbon atoms, is transformed into pyruvic acid, which consists of 3 carbon atoms.

Respiration involves
Gaseous exchange: Intake of oxygen from the atmosphere and release of CO2 → Breathing.
Breakdown of simple food in order to release energy inside the cell → Cellular respiration.

Fate of Pyruvic Acid in Mitochondria: Pyruvic acid undergoes further breakdown within the mitochondria, and the resulting molecules vary based on the type of respiration specific to the organism.

⟹ Types of Respiration

Aerobic Respiration: Aerobic respiration occurs in the presence of oxygen. Pyruvic acid undergoes conversion into carbon dioxide, releasing energy, and culminating in the formation of water molecules.
Anaerobic Respiration: Anaerobic respiration occurs in the absence of oxygen. Pyruvic acid is converted into either ethyl alcohol or lactic acid. Ethyl alcohol typically forms in microbes such as yeast or bacteria during anaerobic respiration. Lactic acid is produced in certain microbes and muscle cells during this process.

breakdown of glucose by various pathways

Pain in Leg Muscles While Running

➥Intense running triggers anaerobic respiration in muscle cells, driven by an increased demand for energy.
➥The process of anaerobic respiration produces lactic acid, contributing to a throbbing pain in the leg muscles.
➥Resting after the activity helps alleviate the pain caused by the deposition of lactic acid in the muscles.

ATP

➥ATP serves as the energy currency within cells.
➥ATP is an acronym for Adenosine Tri-Phosphate.
➥This molecule is generated as a byproduct of reactions such as photosynthesis and respiration.
➥The three phosphate bonds in ATP are high-energy bonds, and their breaking releases a substantial amount of energy.
➥The released energy is subsequently utilized for various metabolic reactions.

Respiration in Humans

➥The human respiratory system is a complex network crucial for breathing, gas exchange, and cellular respiration.
➥A well-organized respiratory system is essential for efficient breathing and gas exchange.
➥Breathing involves inhaling oxygen and exhaling carbon dioxide.
➥Gas exchange occurs in the lungs, where oxygen is supplied to all cells in the body.
➥Cellular respiration takes place in every cell, contributing to overall energy production and cellular function.

Respiratory System

➥The human respiratory system involves the nose, nasal cavities, pharynx, larynx, trachea/windpipe, bronchi, bronchioles, and alveoli.
➥Bronchioles and alveoli are enclosed in a pair of lungs.
➥The rib cage, muscles associated with the rib cage, and diaphragm all help in the inhalation and exhalation of gases.
➥The exchange of gases takes place between an alveolar surface and surrounding blood vessels.
➥Alveoli provide a large surface area for the exchange of gases.

Inhalation and Exhalation

Inhalation is the process of taking in air rich in oxygen.
Exhalation is the process of expelling air rich in carbon dioxide.
A single breath involves both inhalation and exhalation.
Individuals breathe multiple times throughout the day.
The frequency of breaths in one minute is referred to as the breathing rate.

Cellular Respiration

Cellular respiration involves a series of metabolic reactions within cells, transforming the biochemical energy derived from food into a chemical compound known as adenosine triphosphate (ATP).

Respiration in Plants

In contrast to animals and humans, plants lack specialized structures for gaseous exchange.
Gaseous exchange in plants occurs through stomata in leaves and lenticels in stems.
Plant roots, stems, and leaves exhibit a considerably lower respiratory rate compared to animals.

Transportation

All living organisms, including animals, rely on essential components like air, water, and food for survival, obtained through processes such as breathing, drinking, and eating.
Transportation systems, like vascular tissue in plants and specialized circulatory systems in animals, facilitate the distribution of necessary substances to cells and tissues.

Transportation in Humans

The circulatory system in humans serves as the primary transportation mechanism.
Comprising blood, blood vessels, and the heart, it facilitates the supply of oxygen and nutrients while eliminating carbon dioxide and other excretory products.
Additionally, the circulatory system plays a vital role in the body's immune response, aiding in the fight against infections.

HEART

The heart is a muscular organ composed of cardiac muscles.
The heart, compact enough to fit within an adult's wrist, serves as a vital pumping organ for blood circulation.
Comprising four chambers—right atrium, right ventricle, left ventricle, and left atrium—the human heart orchestrates the rhythmic processes of systole (contraction of cardiac muscles) and diastole (relaxation of cardiac muscles).
Through systole and diastole, the heart efficiently propels and circulates blood, ensuring essential oxygen and nutrients reach the body's tissues and organs.

ARTERIES

Thick-walled blood vessels transport oxygenated blood from the heart to various organs, with the exception of pulmonary arteries.
Pulmonary arteries deviate from the norm by carrying deoxygenated blood from the heart to the lungs, where the blood undergoes oxygenation.

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 the lungs to the heart.
Valves are present in veins to prevent backflow of blood.

Capillaries

Capillaries are blood vessels distinguished by their single-cell walls.
Blood, a connective tissue, functions as the carrier for various substances in the body and is comprised of three main components: Plasma, Blood cells, and Platelets.

Blood Plasma

This is a light-colored fluid primarily composed of water, constituting the matrix of blood.

Blood Cells

There are two main types of blood cells: Red Blood Cells (RBCs) and White Blood Cells (WBCs).

Red Blood Cells (RBCs)

These cells are red due to the presence of the pigment hemoglobin. Hemoglobin readily binds with oxygen and carbon dioxide, facilitating the transport of oxygen.
Additionally, a portion of carbon dioxide is transported through hemoglobin.

White Blood Cells (WBCs)

These cells are pale white and play a crucial role in the immune system.

Platelets

Responsible for blood coagulation, platelets serve as a defense mechanism preventing excessive blood loss in the event of an injury.

LYMPH

Lymph resembles blood but lacks red blood cells (RBCs).
Formed from leaked fluid in tissues, lymph is collected by lymph vessels and returns to blood capillaries.
Lymph, a yellowish fluid with fewer proteins than blood, plays a vital role in the immune system.
It flows from tissues to the heart, assisting in transportation and germ destruction.

Double Circulation

The heart receives oxygenated blood from the lungs, pumps it to various parts of the body, and then receives it back for another circulation.
Consequently, the blood completes a full round through the body, passing once through the right half as deoxygenated blood and once through the left half as oxygenated blood.

Transportation in Plants

Transportation is a crucial process in plants.
It encompasses the movement of water and essential nutrients throughout the plant to support its survival.
Plants conduct the transportation of food and water through distinct pathways.

Xylem

Xylem is responsible for transporting water.

Phloem

Phloem is dedicated to the transportation of food.
Energy is used from ATP (adenosine triphosphate) for the transport of food.

Transport of Water

Root cells in contact with the soil actively absorb ions, establishing a concentration difference between the root and the soil.
Water moves into the root from the soil to equalize this ion concentration difference. Additionally, the evaporation of water molecules from leaf cells generates suction, drawing water from the xylem cells in the roots.

Transpiration

Transpiration refers to the loss of water in vapor form from the plant's aerial parts.
This process aids in the absorption and upward transport of water and dissolved minerals from the roots to the leaves, contributing to temperature regulation.

Transport of Food and Other Substances

The movement of soluble products resulting from photosynthesis is termed translocation, and it takes place within the vascular tissue section called the phloem.
Energy is harnessed to accomplish translocation in the phloem.
Substances such as sucrose are actively transferred into phloem tissue, utilizing energy derived from ATP.

Xylem vs. Phloem

Xylem: Transports water and minerals from the roots to various parts of the plant. No energy is used.
Phloem: Transports the products of photosynthesis from the leaves to other parts of the plant. Energy is used from ATP (adenosine triphosphate).

Excretion in Plants

➥ Plants remove waste products through:

Gaseous Excretion: Through stomata and lenticels.
Excretion in Roots: Removal of waste through root exudates.

Class - 10th