Glossary

• Active transport = movement of ions/molecules across a cell membrane to a region of higher concentration assisted by enzymes and requiring energy
• Alveoli = tiny air sacs that act as the site of gas exchange between air and blood
• Amylases = enzyme that catalyses the hydrolysis of starch into sugars
• Bile salts = component of bile that helps break down fat, aid digestion, absorb important vitamins and eliminate toxins
• Bronchi = two large tubes that carry air from the oesophagus to the lungs
• Bronchioles = small airways connecting the bronchi and alveoli
• Causal relationship = direct cause and effect relationship between two variables
• Chlyomicrons = lipoprotein particles that transport dietary lipids around the body
• Collagen = main structural protein providing structure support or strength to connective tissue
• Correlation = mutual relationship between two or more things
• Countercurrent flow = biological mechanism in which there is an exchange of a substance between fluids flowing in opposite directions
• Cuticle = Variety of tough but flexible outer coverings of an organism that provides protection
• Egestion = process of discharging undigested food from the body
• Emulsification = process of dispersing one liquid in another immiscible liquid
• Endopeptidases = Enzyme which breaks peptide bonds other than terminal ones in a peptide chain
• Epithelial cells = cells which form a membrane that allows selective diffusion of materials to pass through
• Exocytosis = Form of active transport in which a cell transports molecules out of a cell requiring energy
• Exopeptidases = peptidase that hydrolyses the terminal peptide bond
• Exhalation = flow of breath out of an organism
• Gill filaments = Attached to the gill arch, covered with capillaries where gas exchange takes place
• Ileum = final portion of small intestine that absorbs any final nutrients
• Inhalation = drawing air into the respiratory tract
• Intercostal muscle = muscle groups situated in between ribs that create and move the chest wall
• Lacteal = lymphatic vessel located in the center of each intestinal villus that provides a unique route for drainage of absorbed lipids
• Lipase = enzymes that catalyse the hydrolysis of fats
• Lumen = space with the tubes, tracts, cavities and cells of the body
• Membrane-bound dipeptidases = enzymes found within membranes that hydrolyse dipeptides into single amino acids
• Membrane-bound disaccharides = disaccharides that break down disaccharides into monosaccharides in the small intestine
• Micelles = loosely bound aggregation of hundreds of atoms, ions or molecule forming a colloidal particle
• Microvilli = hair-like projections on the surface of epithelial cells which increase their absorbing area
• Osmosis = the movement of water molecules from a region of high water concentration to a region of low water concentration across a partially permeable membrane
• Pancreas = organ in the body that helps with digestion and regulate blood sugar
• Rib cage = protects organs in the thoracic vertebrae, helps in respiration, provides support for upper extremities
• Salivary glands = makes saliva which aids in digestion, keeps the mouth moist and supports healthy teeth
• Spiracles = opening in the exoskeletons of insects allowing air to enter the trachea
• Stomata = pore found in the epidermis of leaves that controls that rate of gas exchange
• Tidal volume = amount of air that moves in or out of the lungs with each respiratory cycle
• Tracheae = tube made up of cartilage rings that connects the oesophagus to bronchi
• Ventilation = movement of air into and out of the lungs during breathing
• Tracheoles = fine respiratory tube of the trachea of an insect