BIO100 Key Terms - Ch 1 & 2

applied science

a form of science that solves real

atom

a basic unit of matter that cannot be broken down by normal chemical reactions

basic science

science that seeks to expand knowledge regardless of the short

biology

the study of life

biosphere

a collection of all ecosystems on Earth

cell

the smallest fundamental unit of structure and function in living things

community

a set of populations inhabiting a particular area

control

a part of an experiment that does not change during the experiment

deductive reasoning

a form of logical thinking that uses a general statement to predict specific results

descriptive science

a form of science that aims to observe, explore, and find things out

ecosystem

all living things in a particular area together with the abiotic, nonliving parts of that environment

eukaryote

an organism with cells that have nuclei and membrane

evolution

the process of gradual change in a population that can also lead to new species arising from older species

falsifiable

able to be disproven by experimental results

homeostasis

the ability of an organism to maintain constant internal conditions

hypothesis

a suggested explanation for an event, which can be tested

hypothesis

based science

inductive reasoning

a form of logical thinking that uses related observations to arrive at a general conclusion

life science

a field of science, such as biology, that studies living things

macromolecule

a large molecule typically formed by the joining of smaller molecules

molecule

a chemical structure consisting of at least two atoms held together by a chemical bond

natural science

a field of science that studies the physical world, its phenomena, and processes

organ

a structure formed of tissues operating together to perform a common function

organ system

the higher level of organization that consists of functionally related organs

organelle

a membrane

organism

an individual living entity

peer

reviewed article

phylogenetic tree

a diagram showing the evolutionary relationships among biological species based on similarities and differences in genetic or physical traits or both

physical science

a field of science, such as astronomy, physics, and chemistry, that studies nonliving matter

population

all individuals within a species living within a specific area

prokaryote

a unicellular organism that lacks a nucleus or any other membrane

science

knowledge that covers general truths or the operation of general laws, especially when acquired and tested by the scientific method

scientific law

a description, often in the form of a mathematical formula, for the behavior of some aspect of nature under certain specific conditions

scientific method

a method of research with defined steps that include experiments and careful observation

scientific theory

a thoroughly tested and confirmed explanation for observations or phenomena

tissue

a group of similar cells carrying out the same function

variable

a part of an experiment that can vary or change

acid

a substance that donates hydrogen ions and therefore lowers pH

adhesion

the attraction between water molecules and molecules of a different substance

amino acid

a monomer of a protein

anion

a negative ion formed by gaining electrons

atomic number

the number of protons in an atom

base

a substance that absorbs hydrogen ions and therefore raises pH

buffer

a solution that resists a change in pH by absorbing or releasing hydrogen or hydroxide ions

carbohydrate

a biological macromolecule in which the ratio of carbon to hydrogen to oxygen is 1:2:1; carbohydrates serve as energy sources and structural support in cells

cation

a positive ion formed by losing electrons

cellulose

a polysaccharide that makes up the cell walls of plants and provides structural support to the cell

chemical bond

an interaction between two or more of the same or different elements that results in the formation of molecules

chitin

a type of carbohydrate that forms the outer skeleton of arthropods, such as insects and crustaceans, and the cell walls of fungi

cohesion

the intermolecular forces between water molecules caused by the polar nature of water; creates surface tension

covalent bond

a type of strong bond between two or more of the same or different elements; forms when electrons are shared between elements

denaturation

the loss of shape in a protein as a result of changes in temperature, pH, or exposure to chemicals

deoxyribonucleic acid (DNA)

a double

disaccharide

two sugar monomers that are linked together by a glycodsidic bond

electron

a negatively charged particle that resides outside of the nucleus in the electron orbital; lacks functional mass and has a charge of –1

electron transfer

the movement of electrons from one element to another

element

one of 118 unique substances that cannot be broken down into smaller substances and retain the characteristic of that substance; each element has a specified number of protons and unique properties

enzyme

a catalyst in a biochemical reaction that is usually a complex or conjugated protein

evaporation

the release of water molecules from liquid water to form water vapor

fat

a lipid molecule composed of three fatty acids and a glycerol (triglyceride) that typically exists in a solid form at room temperature

glycogen

a storage carbohydrate in animals

hormone

a chemical signaling molecule, usually a protein or steroid, secreted by an endocrine gland or group of endocrine cells; acts to control or regulate specific physiological processes

hydrogen bond

a weak bond between partially positively charged hydrogen atoms and partially negatively charged elements or molecules

hydrophilic

describes a substance that dissolves in water; water

hydrophobic

describes a substance that does not dissolve in water; water

ion

an atom or compound that does not contain equal numbers of protons and electrons, and therefore has a net charge

ionic bond

a chemical bond that forms between ions of opposite charges

isotope

one or more forms of an element that have different numbers of neutrons

lipids

a class of macromolecules that are nonpolar and insoluble in water

litmus paper

filter paper that has been treated with a natural water

macromolecule

a large molecule, often formed by polymerization of smaller monomers

mass number

the number of protons plus neutrons in an atom

matter

anything that has mass and occupies space

monosaccharide

a single unit or monomer of carbohydrates

neutron

a particle with no charge that resides in the nucleus of an atom; has a mass of 1

nonpolar covalent bond

a type of covalent bond that forms between atoms when electrons are shared equally between atoms, resulting in no regions with partial charges as in polar covalent bonds

nucleic acid

a biological macromolecule that carries the genetic information of a cell and carries instructions for the functioning of the cell

nucleotide

a monomer of nucleic acids; contains a pentose sugar, a phosphate group, and a nitrogenous base

nucleus

(chemistry) the dense center of an atom made up of protons and (except in the case of a hydrogen atom) neutrons

octet rule

states that the outermost shell of an element with a low atomic number can hold eight electrons

oil

an unsaturated fat that is a liquid at room temperature

periodic table of elements

an organizational chart of elements, indicating the atomic number and mass number of each element; also provides key information about the properties of elements

pH scale

a scale ranging from 0 to 14 that measures the approximate concentration of hydrogen ions of a substance

phospholipid

a major constituent of the membranes of cells; composed of two fatty acids and a phosphate group attached to the glycerol backbone

polar covalent bond

a type of covalent bond in which electrons are pulled toward one atom and away from another, resulting in slightly positive and slightly negative charged regions of the molecule

polypeptide

a long chain of amino acids linked by peptide bonds

polysaccharide

a long chain of monosaccharides; may be branched or unbranched

protein

a biological macromolecule composed of one or more chains of amino acids

proton

a positively charged particle that resides in the nucleus of an atom; has a mass of 1 and a charge of +1

radioactive isotope

an isotope that spontaneously emits particles or energy to form a more stable element

ribonucleic acid (RNA)

a single

saturated fatty acid

a long

solvent

a substance capable of dissolving another substance

starch

a storage carbohydrate in plants

steroid

a type of lipid composed of four fused hydrocarbon rings

surface tension

the cohesive force at the surface of a body of liquid that prevents the molecules from separating

temperature

a measure of molecular motion

trans

fat

triglyceride

a fat molecule; consists of three fatty acids linked to a glycerol molecule