Life Processes

What are Life Processes?

The basic functions performed by living organisms to maintain their life on earth, including nutrition, respiration, transportation, and excretion.

Autotrophic Nutrition

A mode of nutrition in which organisms (like green plants) synthesize their own food from simple inorganic substances like CO_2 and water in the presence of sunlight and chlorophyll.

Photosynthesis Equation

6CO2 + 12H2O \xrightarrow[\text{Chlorophyll}]{\text{Sunlight}} C6H{12}O6 + 6H2O + 6O_2

Heterotrophic Nutrition

A mode of nutrition where organisms depend on other organisms for their food, as they cannot synthesize it themselves.

Holozoic Nutrition

A type of heterotrophic nutrition where organisms take in solid food and break it down inside their bodies (e.g., Amoeba, humans).

Enzymes

Biological catalysts that break down complex food molecules into simpler ones during digestion (e.g., salivary amylase, pepsin, trypsin).

Villi

Finger-like projections in the inner lining of the small intestine that increase the surface area for the absorption of digested food.

Aerobic Respiration

The process of breaking down glucose into CO_2, water, and a large amount of energy in the presence of oxygen.

Anaerobic Respiration

The process of breaking down glucose in the absence of oxygen, producing either ethanol and CO_2 (in yeast) or lactic acid (in human muscle cells).

ATP (Adenosine Triphosphate)

The energy currency for most cellular processes, produced during respiration.

Double Circulation

A circulatory system where blood travels through the heart twice during one complete cycle of the body (e.g., in humans).

Xylem

Vascular tissue in plants responsible for the transport of water and minerals from the roots to the leaves.

Phloem

Vascular tissue in plants responsible for the transport of soluble products of photosynthesis (sucrose and amino acids) from leaves to all parts of the plant.

Nephron

The basic structural and functional unit of the kidney, responsible for the filtration of blood and the formation of urine.

Stomata

Tiny pores present on the surface of the leaves that facilitate massive amounts of gaseous exchange (CO2 and O2) and transpiration.

Guard Cells

Kidney-shaped cells that surround the stomatal pore; they regulate the opening and closing of the pore by swelling when water flows into them.

Bile Juice

A secretion from the liver stored in the gallbladder that makes the acidic food coming from the stomach alkaline and emulsifies fats into small globules.

Pepsin and Trypsin

Protein-digesting enzymes; Pepsin acts in the acidic medium of the stomach, while Trypsin acts in the alkaline medium of the small intestine.

Alveoli

Balloon-like structures within the lungs that provide a maximized surface area for the exchange of gases between the air and the blood capillaries.

Hemoglobin

The respiratory pigment found in red blood cells that has a high affinity for oxygen, transporting it from the lungs to all the tissues of the body.

Blood Platelets

Cell fragments in the blood responsible for coagulation or clotting at the site of an injury to plug leaks and prevent blood loss.

Lymph

A colorless fluid (tissue fluid) that escapes into intercellular spaces, carrying digested fats and draining excess fluid back into the blood.

Translocation

The process of transporting food (sucrose) and other substances like amino acids through the phloem from the leaves to storage organs and growing parts.

Bowman's Capsule

A cup-shaped structure at the upper end of a nephron that encloses the glomerulus and collects the initial filtrate from the blood.