Life Processes Chapter Flashcards

Comprehensive vocabulary flashcards covering the key concepts, biological structures, and processes of the 'Life Processes' chapter, including nutrition, respiration, transportation, and excretion.

Life Processes

The processes which together perform the maintenance job of living organisms, such as nutrition, respiration, transportation, and excretion.

Nutrition

A process to transfer a source of energy (food) from outside the body of the organism to the inside.

Respiration

The process of acquiring oxygen from outside the body and using it in the process of break-down of food sources for cellular needs.

Excretion

The biological process involved in the removal of harmful metabolic wastes (such as nitrogenous materials) from the body.

Autotrophs

Organisms that use simple food material obtained from inorganic sources in the form of carbon dioxide ($CO_{2}$) and water ($H_{2}O$).

Heterotrophs

Organisms that utilize complex substances, which must be broken down into simpler ones using bio-catalysts before they can be used for the upkeep and growth of the body.

Enzymes

Biological catalysts that help break down complex food molecules into smaller molecules.

Photosynthesis

The process by which autotrophs take in carbon dioxide ($CO_{2}$) and water ($H_{2}O$) and convert them into carbohydrates in the presence of sunlight and chlorophyll.

Starch

The form in which carbohydrates not used immediately by plants are stored, serving as an internal energy reserve.

Glycogen

The form in which some of the energy derived from food is stored in the human body.

Chloroplasts

Cell organelles containing chlorophyll, visible as green dots in a leaf cross-section under a microscope.

Stomata

Tiny pores present on the surface of the leaves through which massive amounts of gaseous exchange take place for photosynthesis.

Guard Cells

Cells that regulate the opening and closing of the stomatal pore by swelling when water flows into them or shrinking when the pore closes.

Salivary Amylase

An enzyme in saliva that breaks down starch, which is a complex molecule, to give simple sugar.

Peristaltic movements

Rhythmic contractions of the muscles along the lining of the digestive canal that push food forward.

Pepsin

A protein-digesting enzyme released by the gastric glands in the wall of the stomach.

Mucus

A substance that protects the inner lining of the stomach from the action of hydrochloric acid ($HCl$) under normal conditions.

Villi

Finger-like projections on the inner lining of the small intestine that increase the surface area for absorption and are richly supplied with blood vessels.

Bile salts

Substances from the liver that break down large fat globules in the small intestine into smaller globules to increase enzyme efficiency.

Trypsin

An enzyme secreted by the pancreas used for digesting proteins.

Lipase

An enzyme secreted by the pancreas for breaking down emulsified fats.

Dental plaque

Masses of bacterial cells together with food particles that stick to the teeth, preventing saliva from neutralizing acids.

Pyruvate

A three-carbon molecule formed in the cytoplasm as the first step in the breakdown of the six-carbon glucose molecule.

Anaerobic Respiration

The process of breaking down pyruvate in the absence of oxygen, such as the conversion of pyruvate into ethanol and carbon dioxide in yeast.

Aerobic Respiration

The process of breaking down the three-carbon pyruvate molecule in the mitochondria using oxygen to yield three molecules of carbon dioxide and water.

Lactic Acid

A three-carbon molecule produced in muscle cells during lack of oxygen; its build-up during sudden activity causes cramps.

ATP (Adenosine Triphosphate)

The energy currency for most cellular processes; it releases energy equivalent to $30.5\,kJ/mol$ when the terminal phosphate linkage is broken using water.

Alveoli

Balloon-like structures within the lungs that terminate the bronchial tubes and provide a surface for the exchange of gases.

Haemoglobin

The respiratory pigment in human beings, located in red blood corpuscles, which has a very high affinity for oxygen.

Plasma

The fluid medium of blood in which cells are suspended, transporting food, carbon dioxide, and nitrogenous wastes in dissolved form.

Double Circulation

A circulatory system where blood goes through the heart twice during each cycle of passage through the body, common in vertebrates.

Systolic Pressure

The pressure of blood inside the artery during ventricular systole (contraction), normally about $120\,mm\,\text{of}\,Hg$.

Diastolic Pressure

The pressure of blood in the artery during ventricular diastole (relaxation), normally about $80\,mm\,\text{of}\,Hg$.

Arteries

Thick-walled, elastic vessels that carry blood away from the heart to various organs under high pressure.

Veins

Vessels that collect blood from different organs and bring it back to the heart; they have valves to ensure blood flows only in one direction.

Capillaries

The smallest blood vessels, with walls one-cell thick, where exchange of material between blood and surrounding cells occurs.

Platelets

Blood cells that circulate around the body and plug leaks by helping to clot blood at points of injury.

Lymph (Tissue Fluid)

A colourless fluid containing less protein than plasma that escapes from capillaries into intercellular spaces to assist in transportation and draining excess fluid.

Xylem

Vascular tissue in plants responsible for moving water and minerals obtained from the soil upwards through vessels and tracheids.

Phloem

Vascular tissue in plants that transports products of photosynthesis (sucrose), amino acids, and other substances from leaves to other parts.

Transpiration

The loss of water in the form of vapour from the aerial parts of the plant, helping in the absorption and upward movement of water and minerals.

Translocation

The transport of soluble products of photosynthesis through the phloem, achieved by utilizing energy from ATP.

Nephrons

The basic filtration units in the kidneys, consisting of a cluster of thin-walled capillaries associated with a cup-shaped Bowman's capsule.

Bowman’s capsule

The cup-shaped end of a coiled tube in the nephron that collects the filtrate from the capillary cluster.

Hemodialysis

The process of using an artificial kidney to remove nitrogenous waste products from the blood in case of kidney failure.