Life processes | Important terms & definitions | Class-10

TermsMeaning
NutritionProcess of taking in and utilizing various types of foods by organisms, for obtaining energy necessary for growth and development.
AutotrophsOrganisms who can synthesize their own organic food from simple inorganic sources.
HeterotrophsOrganisms that cannot prepare its own food and depends upon other for its nutritional requirements.
EnzymesThese are the biological catalyst that speed up various biochemical reactions.
CarbohydratesBiological molecule made up of sugar or glucose, required for the production of energy.
ChlorophyllPigments found in green plants essential for the process of photosynthesis. They are located inside the thylakoid of the chloroplast.
StarchThese are storage form of glucose in plants.
GlycogenThese are storage form of glucose in animals.
PhotosynthesisIt refers to the process of synthesis of food by autotrophic organisms by utilizing carbon dioxide and water in the presence of chlorophyll that absorbs the sunlight.
ChloroplastsGreen color plastids that contain the chlorophyll pigments.
StomataStructures in plants that help in the process of exchange of gases and transpiration.
Guard cellsThese are kidney-shaped cells that make up the stomatal aperture.
Parasitic mode of nutritionIt refers to the mode of nutrition where the organism obtains its nutrition from living plants or animals without killing them.
Saprophytic mode of nutritionMode of nutrition where the organism obtains its nutrition from dead and decaying organic matter.
The organism secret certain enzymes to digest the decaying organic matter into simpler products and later absorb them.
Holozoic mode of nutritionIn this kind of nutrition, the organism feed exclusively on solid organic materials. The food is later broken down into simple molecules inside the body of the organism.
PseudopodiaThese are temporary finger-like projections of the cell surface seen in an organism like Amoeba to obtain food.
Peristaltic movementsThe rhythmic contraction and relaxation of the esophagus/food pipe while the bolus/chewed food is moving from the mouth to the stomach.
OesophagusAlso known as food pipe, that connects the mouth and stomach.
Gastric glandsThese are glands located in various portions of the stomach. These glands release mucus, HCl, and pepsinogen.
PepsinogenThe inactive form of the enzyme pepsin.
PepsinEnzyme released in the stomach that requires an acidic condition for its action on proteins.
Sphincter muscleStructure that regulates the movement of chyme/partially digested food from the stomach to the small intestine.
TrypsinProteolytic enzyme released into the small intestine by the pancreas and requires an alkaline medium for its action.
TrypsinogenInactive form of the enzyme trypsin.
BileThe bile is released into the duodenum by pancreas contains bile pigments (bilirubin and bili-verdin), bile salts, cholesterol, and phospholipids but no enzymes
Bile saltsIt helps in emulsification of fat molecules or breaking down of the large fat molecules into smaller fat molecules in the small intestine, making it easier for the enzyme lipase to act on it.
LipaseEnzyme released by the intestinal epithelial cells, that acts on the fats and break it down into fatty acids and glycerol.
VilliThe numerous finger-like projections that are present on the inner side of the small intestine and help in increasing the surface are for the absorption of digested food materials.
They are richly supplied with blood vessels that can take the absorbed food to each and every cell of the body.
RespirationProcess by which food materials are oxidized in cells to release energy.
FermentationsFermentation is an anaerobic (non-oxygen-requiring) pathway for breaking down glucose.
In muscles, lack of oxygen during intense exercise leads to lactate fermentation which ends up with lactic acid and some amount of energy as the product.
GlycolysisThe process of formation of pyruvate from glucose in the cytoplasm through a series of reaction involving several enzymes.
ATPThe energy currency of cells. Adenosine Tri Phosphate. The energy is stored in the phosphate bonds.
Breakdown of one of the terminal phosphate bond leads to the release of 30.5 KJ/mol of energy.
AlveoliThe alveoli are tiny air sacs within the lungs where the exchange of oxygen and carbon dioxide takes place.
HemoglobinIt is the respiratory pigment present in the RBC, giving it the characteristics red color, help in the transport of oxygen in the body.
Blood PlasmaPlasma is a straw coloured, viscous fluid that holds the cells of the blood.
Blood SerumIt is the blood plasma without the clotting factors.
ArteryBlood vessels that carry oxygenated blood from the heart to the tissue sites.
VeinBlood vessels that carry the deoxygenated blood from the tissues back to the heart.
Vena cavaLargest vein in the body. It is of two types- the superior vena cava (brings blood from the upper body parts) and the inferior vena cava (collects blood from the lower body parts).
AortaLargest artery in the body.
CapillariesThese are the smallest of blood vessels. They distribute oxygenated blood from arteries to the tissues of the body and to collect deoxygenated blood from the tissues back into the veins.
Pulmonary arteryBlood vessels that carry deoxygenated blood from the heart to the lungs for gaseous exchange.
Pulmonary veinBlood vessels that carry oxygenated blood from the lungs to the heart after gaseous exchange.
Double circulationIn a single cardiac cycle the blood enters the heart twice. Consists of two circuits of blood passing through heart – pulmonary circulation and systemic circulation.
Pulmonary circulationIn this circulation the deoxygenated blood is pumped from the heart to the lungs, oxygenated blood returns to the heart from the lungs.
Systemic circulationHere the oxygenated blood is pumped from the heart to all the organs and the deoxygenated blood is collected from the organs back to the heart.
SphygmomanometerIt is an instrument to measure the blood pressure.
HypertensionAlso known as high blood pressure where the blood pressure in the arteries is high.
PlateletsComponent in the blood responsible for the blood clotting/coagulation.
LymphLymph is the fluid that circulates throughout the lymphatic system.
Its composition is similar to plasma but is colorless and contains lesser protein.
It carries the digested and absorbed fats from intestine and drains the excess fluid from extracellular space back into the blood.
TranspirationThe loss of water from the leaf surface in the form of water vapors.
TranslocationTransport of soluble products of photosynthesis via phloem.
UretersTube like structure that connects the kidney and the urinary bladder.
UrethraTube like structure that runs down from the lower end of urinary bladder to conduct urine to the exterior.
NephronsBasic filtration unit of the kidneys. Consists of the bowmen’s capsule and renal tubules.
Bowman’s capsuleIt is a cup-like sack at the beginning of the tubular component of a nephron that performs the first step in the filtration of blood to form urine.
GlomerulusIt consists of a tuft of small blood vessels called capillaries located within Bowman’s capsule within the kidney.