Term | Definition |
food web | the overlapping food chains of an ecosystem |
ecosystem | a biological community and its abiotic environment |
decomposers | an organism that lives on decaying organic material from which it obtains energy |
chemical energy | energy stored in the structure of molecules |
free energy | energy that is available to do work |
metabolism | the sum of all the chemical changes taking place in an organism |
producers | an autotroph; any organism that produces its own food |
consumers | a heterotroph; an organism that feeds on other organisms or on their organic waste |
abiotic factors | referring to a physical or nonliving component of an ecosystem |
biotic factors | relating ro a living component of an ecosystem |
ATP | adenosine triphosphate; a compound that has three phosphate groups and is used by cells to store energy and to fuel many metabolic processes |
ADP | adenosine triphosphate; a compound that has three phosphate groups and is used to by cells to store energy and to fuel many metabolic processes |
entropy | a measure of the degree of disorganization of a system, that is, how much energy in a system has become so dispersed that is is no longer available to do work |
synthesis | the process of building chemical compounds from smaller components by means of chemical reactions |
decomposition | the process of breaking substances down into smaller chemical units |
autotrophs | an organism that forms its own food molecules (carbon compounds) from abiotic materials |
first law of thermodynamics | the law derived from the principle of the conversation of energy stating that energy can be neither created nor destroyed, but it can be transferred or transformed |
second law of thermodynamics | the law stating that energy transfers and transformations increase the entropy of the universe |
enzymes | a protein or part-protein molecule made by an organism and used as a catalyst in a specific biochemical reaction |
villi | fingerlike projections of the small intestine that increases surface area for absorption of digested food |
pepsin | a protein splitting enzyme secreted by the gastric glands of the stomach |
trypsin | an enzyme in pancreatic juice that breaks down protein molecules |
lipase | a fat-digesting enzyme |
capillary | a microscopic blood vessel penetrating the tissues and consisting of a single layer of cells that allows exchange between the blood and tissue fluids |
feces | the waste material expelled from the digestive tract |
epiglottis | flap of cartilaginous tissue at the base of the tongue in mammals; prevents food from entering the trachea, the airway to the lungs, during swallowing |
salivary amylase | an enzyme in saliva that begins digestion of starch; converts starch to disaccharides |
intracellular digestion | the breakdown of nutrients within a cell |
extracellular digestion | the breakdown of nutrient molecules outside of cells |
active site | the portion of an enzyme that attaches to the substrate through weak chemical bonds |
substrate | a molecule on which enzymes act |
calatlyst | a chemical that promotes a reaction between other chemicals by reducing the energy required to activate the reaction; may take part in the reaction but emerges in its original form |
habitat | type of place where an organism lives |
biosphere | the other potion of Earth--air, water, and soil--where life is found |
heterotroph | an organism that obtains carbon compounds from other organisms |
chemical reactions | change in chemical bonds that produces one of more new substances |