all living things in a particular area, along with all the nonliving components of the environment with which life interacts (soil, water, atmospheric gases, and light).
the entire array of organisms inhabiting a particular ecosystem/the set of populations that inhabit a particular area.
a team of organs that cooperate in a specific function.
ex. human digestive system-tounge, stomach, intestines
groups of similar cells that perform a specific function in an organism (allow the organ to function).
subdivided by internal membranes into various membrane-enclosedorganelles.
DNA is not separated from the rest of the cell by the enclosure in a membrane-bounded nucleus.
the principle that, among the range of inherited trait variations, those that lead to increased reproduction and survival will most likely be passed on to succeeding generations.
an explanation that is a broad in scope, generates new hypotheses, and is supported by a large body of evidence (broad).
a substance consisting of two or more different elements combined in a fixed ratio.
ex. sodium chloride (NaCl) (table salt)= sodium (Na) and chlorine (Cl) in a 1:1 ratio.
-froms when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atoms.
-very weak bonds; occurs when a hydrogen atom in one molecule is attracted to the electronegative atom in another molecule.
Van der Waals
Weak interactions that occur when atoms and molecules are very close together; based on the fact that because electrons are in constant motion, they may accumulate by chance in one part of the molecule or another, thus creating a charge for that instant.
ex. gecko walks up a wall (so numerous can support the gecko's body weight).
Moderation of Temperature
water moderates air temperature by absorbing heat from air that is warmer and releasing the stored heat air that is cooler. occurs because water can absorb or release a relatively large amount of heat with only a slight change in its own temperature.
the amount of heat that must be absorbed or lost for 1g of that substance to change its temperature by 1°C.
Heat of Vaporization
the quantity of heat a liquid must absorb for 1g to be converted from the liquid to the gaseous state.
as a liquid evaporates, the surface area of the liquid that remains behind cools down. occurs because the "hottest" molecules, those with the greatest kinetic energy, are more likely to leave as gas.
Hydrogen Ion (H+)
is transferred-(the hydrogen atom leaves its electron behind)-when a hydrogen atom participating in a hydrogen bond between two water molecules shifts from one molecule to another. results in a Hydronium ion
substances that minimize changes in the concentrations of H+ and OH-. works by accepting H+ from the solution when they are in excess and donating H+ to the solution when they have been depleted.
snow, rain, or fog with a pH lower or more acidic that pH 5.6. caused primarily by the presence of sulfur oxides and nitrogen oxides-gaseous compounds that react with water in the air to form strong acids. major source is burring of fossil fuels.
complex molecules organized around skeletons of carbon atoms arranged in rings or chains; includes biomolecules molecules synthesized by living organisms.
compounds that have the same number of atoms of the same elements but different structures and hence different properties.
the monovalent group -OH in such compounds as bases and some acids and alcohols. polar-electronegative oxygen. attracts water molecules helping dissolve organic compounds.
ketones-carbonyl group is within a carbon skeleton
aldehydes-carbonyl group is at the end of a carbon skeleton.
carboxyl acids-organic acids. source of H+. covalent bond between H and O is so polar H+ tend to dissociate reversibly.
organic phosphates. makes the molecule of which it is part of an anion. can transfer energy between organic molecules.
A giant molecule formed by the joining of smaller molecules, usually by a condensation reaction. Polysaccharides, proteins, and nucleic acids are macromolecules.
Dehydration Reaction/Condensation Reaction
when monomers are connected by a reaction in which two molecules covalently bond together through loss of a water molecule.
simplest carbohydrates/singe sugars/simple sugars. generally have molecular formulas that are some multiple of CH20. nutrients for cells.
a common component of animal cell membranes and is also the precursor from which other steroids are synthesized. many hormones (including sex hormones) are steroids produced from cholesterol.
selective acceleration of chemical reactions.
ex. digestive enzymes catalyze the hydrolysis in food.
(strengthen and protect cells and tissues) ex. collagen strengthens animal tissue. keratin the protein of hair, horns, and other skin appendages.
Storage of amino acids.
ex. ovalbumin-protein of egg white-used as an amino acid source for the developing embryo. casein-protein for milk-major source of amino acids for baby mammals.
transport of other substances.
ex. hemoglobin-tranports oxygen from the lungs to other parts of the body. other proteins transports molecules across cell membranes.
coordination of an organism's activities.
ex. insulin-hormoe secreted by the pancreas- helps regulate the concentration of sugar in the blood.
response of cell to chemical stimuli.
ex. receptors built into the membrane of a nerve cell detect chemical signals released by other nerve cells.
Contractile and Motor Proteins
ex. actin and myosin-responsible for the movement of muscles. other proteins are responsible for the undulations of the organelles called cilia and flagella.
the chemical bond that forms between the carboxyl group of one amino acid and the amino group of another amino acid through dehydration reaction.
The localized, repetitive coiling or folding of the polypeptide backbone of a protein due to hydrogen bond formation between peptide linkages.
-Irregular contortions of a protein molecule due to interactions of side chains involved in hydrophobic interactions, ionic bonds, hydrogen bonds, and disulfide bridges.
-The third level of protein structure; the overall, three-dimensional shape of a polypeptide due to interactions of the R groups of the amino acids making up the chain.
The fourth level of protein structure; the shape resulting from the association of two or more polypeptide subunits.
(thermodynamics) a thermodynamic quantity representing the amount of energy in a system that is no longer available for doing mechanical work
(thermodynamics) a thermodynamic quantity equal to the internal energy of a system plus the product of its volume and pressure.
the energy that an atomic system must acquire before a process (such as an emission or reaction) can occur.
breakdown of more complex substances into simpler ones with release of energy. exergonic.
synthesis of more complex substances from simpler ones. endergonic. delta G is negative. high in reactants low in products.
Adenosine Triphosphate (ATP)
three (negatively charged) phosphate groups, nitrogenous base, sugar ribose.
-one of the principal chemical compounds that living things use to store and release energy.