chap 1-4 bio terms

order

highly organized structures that consist of one or more cells

reproduction

reproduce their own kind- genes(DNA) are passed to the next generation

evolutionary adaptations

adaptations that are best suited for their environment evolve over generations because they ensure reproductive success

regulation

organisms maintain a beneficial controlled internal environment

cells

structural and functional units of life

biology

the scientific study of life

cell

structural and functional unit of life

the three domains of life

bacteria, archaea, and eukarya

emergent properties

new properties in each higher structural level of life that did not exist in lower levels

science

is a wat of knowing- an approach to understanding the natural world

hypothesis

a proposed explanation for an observation or a set of observations. - a prediction that can be tested - will never be proven, only supported

theory

an explanatory idea that is broad in scope, has been extensively tested with many experiments, and is supported by a large body of evidence - will never be proven, only supported

independent variable

the factor that is manipulated

dependent variable

the measure used to judge the outcome of the experiment

controlled experiment

compares an experimental group with a control group

evolution

the process of change that has transformed life of Earth from its earliest forms to the vast array of organisms living today

natural selection

a theory where populations of living organisms adapt and change to their environment

artificial selection

the selective breeding of plants and animals- humans also act as agents of evolution

DNA

the genetic material of life; responsible for heredity and for programming the activities of a cell by providing the master instructions

gene

a specific sequence of DNA that codes for a particular protein or set of proteins

signaling

information from the external and internal environment- includes the stimuli, signals, and pathways that regulate body processes and gene expression

dna

a nucleic acid - two strands coiled together into a double helix

gene expression

flow of genetic information from gene to protein

element

a substance that cannot be broken down into other substances

compound

a substance consisting of two or more different elements in a fixed ratio

atom

the smallest unit of matter that still retains the properties of an element

the three subatomic particles

neutrons-protons- and electrons

nucleus

the small dense region at the center of an atom that houses the neutrons and protons

where are electrons located

they orbit the nucleus

atomic number

the unique number of protons relating to the element

atomic mass (mass number)

the sum of the elements protons and neutrons in the nucleus

isotopes

have the same number of protons but different numbers of neutrons

radioactive isotopes

meaning the nucleus is unstable and it decays

electron shells

a level of electrons with a characteristic distance from the nucleus

chemical bonds

at atom whose outer electron shell is not full tends to interact with other atoms - they share gain or lose electrons

ionic bond

the transfer of an electron between atoms results in an attraction

ion

a atom or molecule with an electrical change

covalent bond

atoms do not transfer electrons but they share them

salt

a synonym for an ionic compound

ion

an atom or molecule with an electrical charge resulting from a gain or loss of one or more electrons

nonpolar covalent bond

electrons are shared equally because the atoms are equal in electronegativity

polar covalent bonds

electrons are pulled closer to the more electronegative atom

hydrogen bond (weak)

hydrogen atoms of a water molecule are attached to oxygen by polar covalent bonds

polar molecule

possesses both positive and negative charge

chemical reaction

breaking existing chemical bonds and forming new ones

reactants

before the chemical reaction

products

after the chemical reaction

cohesion

molecules of the same kind sticking together

adhesion

clinging of one substance to another

surface tension

a measure of how difficult it is to break the surface of a liquid

thermal energy

the energy associated with the random movement of atoms and molecules

heat

thermal energy in transfer from warmer to a cooler body of matter

temperature

intensity of heat

evaporative cooling

when a substance evaporates, the surface of the liquid that remains behind cools down

solution

a liquid consisting of uniform mixture of two or more substances

solvent

results from the polarity of its molecules

solutes

dissolves when water molecules surround them

pH scale

describes how acidic or basic a solution is

buffer

minimizes changes in pH by binding or releasing Hydrogen ions

organic compounds

contains carbon (and usually hydrogen) with covalent bonds

hydrocarbons

elements composed of only carbon and hydrogen

fossil fuels

hydrocarbon fuels formed in the geologic past from living organisms

polymers

identical or similar budling blocks strung together

macromolecule

a giant polymer

dehydration reaction

monomers linked together to form polymers

hydrolysis

when polymers are broken apart

enzymes

specialized macromolecules that speed up reactions

carbohydrates

macromolecules that contain carbon, hydrogen and oxygen

monosaccharides

sugar monomer

disaccharide

when two monosaccharides bond together

cellulose

structural - found in plant cell walls

chitin

a component of insect and crustacean and fungal cell walls

lipids

organic molecules that contain mainly carbon and hydrogen linked by nonpolar covalent bonds

hydrophobic

“water fearing’’

fats

lipids that consist of glycerol linked to three fatty acids

unsaturated fatty acids

have double bonds in the fatty acid chain

saturated fatty acids

fatty acids that are densely packed and solid at room temp

trans fat

unsaturated fats formed artificially during hydrogenation that are linked to health risks

phospholipids

components of cell membranes

proteins

polymer made up of amino acids that are folded into 3-demensional structures

enzymes

proteins that catalyze chemical reactions

denaturation

when a protein unravels, loses its specific shape, and loses its function

primary structure of a protein

the sequence of amino acids in its polypeptide chain

secondary structure

coiling or folding of the chain, stabilized by hydrogen bonds

tertiary structure

the overall three- dimensional shape of a polypeptide, resulting from interactions among R groups

quaternary structure

proteins made of more than one polypeptide

nucleotides

the monomers that make up nucleic acids

DNA

double helix

RNA

single polynucleotide chain

cell

basic unit of living matter

light microscope

can display living cells

cell theory

all living things are composed of cells and all cells come from other cells

plasma membrane

is a phospholipid bilayer with embedded proteins that regulates the flow of material into and out of the cell

cytosol

the jelly- like fluid where the cellular components are suspended

prokaryotic cells

consist of bacteria and archaea

eukaryotic cells

all forms of life that are placed in domain Eukarya

organelles

a small structure in a cell that is surrounded by a membrane and has specific function

nucleus

houses the cells DNA

endomembrane system

membranes that are inside the cell

smooth ER

synthesizes lipids and processes toxins