Life Processes Lecture Notes

Vocabulary flashcards covering the biological concepts of nutrition, respiration, transportation, and excretion in plants and animals based on the Life Processes lecture.

Life processes

The essential maintenance functions which together perform the job of keeping living organisms alive even when they are not performing active movements.

Nutrition

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

Respiration

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

Excretion

The biological process involved in the removal of harmful metabolic waste by-products, such as nitrogenous materials, from the body.

Autotrophs

Organisms that fulfill their carbon and energy requirements using simple inorganic sources like $CO_2$ and water, such as green plants and some bacteria.

Enzymes

Biological catalysts that break down complex substances into simpler ones to be used for the upkeep and growth of the body.

Photosynthesis

The process by which autotrophs take in $CO_2$ and water and convert them into carbohydrates in the presence of sunlight and chlorophyll.

Starch

The internal energy reserve in plants where carbohydrates not used immediately are stored.

Glycogen

The form in which energy derived from food is stored in the human body for later use.

Chloroplasts

Cell organelles containing chlorophyll where the process of photosynthesis takes place.

Stomata

Tiny pores present on the surface of leaves through which massive amounts of gaseous exchange and transpiration occur.

Guard cells

Cells that control the opening and closing of stomatal pores by swelling when water flows into them and shrinking when it does not.

Heterotrophs

Organisms that utilize complex substances and depend directly or indirectly on autotrophs for survival, including animals and fungi.

Parasitic nutritive strategy

An approach where organisms like cuscuta, ticks, or leeches derive nutrition from plants or animals without killing them.

Amoeba

A single-celled organism that takes in food using temporary finger-like extensions of the cell surface to form a food-vacuole.

Salivary amylase

An enzyme in saliva that breaks down starch, a complex molecule, into simple sugar.

Peristaltic movements

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

Pepsin

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

Villi

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

Anaerobic respiration

The breakdown of pyruvate into ethanol and carbon dioxide that takes place in the absence of oxygen, commonly seen in yeast.

Aerobic respiration

The process of breaking down pyruvate in the mitochondria using oxygen to produce carbon dioxide, water, and a high amount of energy.

ATP

The energy currency for most cellular processes; the terminal phosphate linkage releases energy equivalent to $30.5\,kJ\,mol^{-1}$ when broken.

Alveoli

Balloon-like structures in the lungs that provide a surface for gas exchange and are surrounded by an extensive network of blood vessels.

Haemoglobin

The respiratory pigment in human red blood corpuscles that has a high affinity for oxygen.

Arteries

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

Veins

Blood vessels with valves that ensure blood flows only toward the heart and collect blood from different organs.

Double circulation

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

Systolic pressure

The pressure of blood inside the artery during ventricular contraction, normally about $120\,mm\,Hg$.

Diastolic pressure

The pressure in the artery during ventricular relaxation, normally about $80\,mm\,Hg$.

Lymph

A colourless tissue fluid similar to plasma but with less protein, which drains excess fluid and carries digested fat.

Xylem

Vascular tissue in plants responsible for the upward movement of water and minerals obtained from the soil.

Phloem

Vascular tissue in plants that transports products of photosynthesis, 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, creating a suction pull for water movement.

Translocation

The transport of soluble products of photosynthesis in the phloem using energy from ATP.

Nephrons

The basic filtration units in the kidneys composed of a cluster of thin-walled capillaries and a cup-shaped Bowman's capsule.

Hemodialysis

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