Chapter 5: Life Processes Vocabulary

A comprehensive vocabulary flashcard set covering key terms, structures, processes, and quantitative details from Chapter 5: Life Processes.

Life Processes

The essential maintenance functions and activities performed together by living organisms to prevent damage and breakdown, continuing even when at rest.

Nutrition

The process of transferring a source of energy, or food, from outside the body of an individual organism to the inside.

Autotrophs

Organisms, such as green plants and some bacteria, that fulfill their carbon and energy requirements using simple inorganic sources like carbon dioxide and water.

Heterotrophs

Organisms, including animals and fungi, whose survival depends directly or indirectly on autotrophs by utilizing complex organic substances that must be broken down.

Enzymes

Biological catalysts used by living organisms to break down complex substances into simpler ones for body maintenance and growth.

Photosynthesis

The process by which autotrophs take in carbon dioxide and water from outside and convert them into carbohydrates in the presence of sunlight and chlorophyll.

Starch

The carbohydrate molecule that serves as an internal energy reserve in plants, stored when carbohydrates are not used immediately.

Glycogen

The molecule in which unused energy derived from consumed food is stored within the human body.

Chloroplasts

Cell organelles containing chlorophyll that appear as green dots in microscopic cross-sections of leaf cells.

Stomata

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

Guard Cells

Specialized cells that regulate the opening and closing of stomatal pores by swelling when water flows in and shrinking when water leaves.

Parasitic Nutritive Strategy

A nutritional method in which organisms derive nutrition from host plants or animals without killing them, practiced by organisms like Cuscuta, ticks, lice, leeches, and tape-worms.

Food-vacuole

A temporary organelle formed in Amoeba when finger-like cell surface extensions engulf and fuse over a food particle.

Cilia

Hair-like structures covering the entire surface of Paramoecium that move food to a specific intake spot.

Salivary Amylase

An enzyme present in saliva that breaks down complex starch molecules into simple sugars.

Peristaltic Movements

Rhythmic muscular contractions occurring along the lining of the alimentary canal to push food forward.

Pepsin

A protein-digesting enzyme secreted by gastric glands in the stomach wall that acts in an acidic environment created by hydrochloric acid.

Villi

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

Bile Juice

A liver secretion that converts acidic food from the stomach to an alkaline state and uses bile salts to emulsify large fat globules into smaller ones.

Trypsin

An enzyme present in pancreatic juice that functions to digest proteins in the small intestine.

Lipase

An enzyme present in pancreatic juice responsible for breaking down emulsified fats.

Dental Plaque

A sticky mass of bacterial cells and food particles on teeth that prevents saliva from reaching the tooth surface to neutralize acid.

Pyruvate

A three-carbon molecule produced in the cytoplasm during the initial step of glucose breakdown in cellular respiration.

Anaerobic Respiration

The breakdown of glucose or pyruvate in the absence of oxygen, such as during fermentation in yeast, yielding ethanol, carbon dioxide, and energy.

Aerobic Respiration

The breakdown of pyruvate in the mitochondria using oxygen to produce carbon dioxide, water, and a large release of energy.

Lactic Acid

A three-carbon molecule formed from pyruvate breakdown in muscle cells during a lack of oxygen, causing cramps.

Adenosine Triphosphate (ATP)

The universal cellular energy currency synthesized from ADP and inorganic phosphate during respiration, releasing equivalent energy of $30.5\,kJ\,mol^{-1}$ when its terminal phosphate linkage breaks.

Alveoli

Balloon-like structures at the end of respiratory passages in the lungs surrounded by blood vessels where exchange of gases occurs.

Haemoglobin

A respiratory pigment present in human red blood corpuscles that has a high affinity for oxygen and carries it to tissues.

Double Circulation

A circulatory pathway in which blood passes through the heart twice during each complete circuit of the body.

Systolic Pressure

The pressure exerted by blood against artery walls during ventricular contraction (systole), normally around $120\,mm\text{ of Hg}$.

Diastolic Pressure

The pressure exerted by blood against artery walls during ventricular relaxation (diastole), normally around $80\,mm\text{ of Hg}$.

Sphygmomanometer

An instrument used to measure arterial blood pressure.

Capillaries

The smallest blood vessels, having walls one-cell thick, across which exchange of material between blood and tissues occurs.

Platelets

Circulating blood cells that prevent loss of blood and pressure by clotting blood at points of injury.

Lymph

A colourless fluid escaping from blood capillaries into intercellular tissue spaces that transports digested fat and drains excess fluid back into blood.

Transpiration

The evaporation of water in the form of vapour from the aerial parts of a plant, driving suction pull for water and mineral transport.

Translocation

The active transport of soluble products of photosynthesis, amino acids, and other materials through the phloem tissue using ATP energy.

Excretion

The biological process involved in the removal of harmful metabolic wastes, particularly nitrogenous compounds, from the body.

Nephron

The basic microscopic filtration unit packed inside the kidney that removes nitrogenous wastes from blood.

Bowman's Capsule

The cup-shaped end of a coiled tubule in a nephron that collects filtrate from the enclosed cluster of blood capillaries.

Hemodialysis

A clinical procedure using an artificial kidney containing semi-permeable tubes suspended in dialysing fluid to filter nitrogenous wastes from a patient's blood.