ch 1-3 biology

biology

scientific study of life

independent variable

manipulated; changed by the experimenter

quantitative data

can be counted or measured

qualitative data

cannot be counted or measured

control variables

remains the same throughout the entire experiment

control group

does not receive the independent variable; serves as the comparison for the experimental group

experimental group

receives the independent variable

dependent variable

changes in response to the manipulated variable

evolution

process of change that transforms life; core theme of biology

biosphere

all the environments on earth that support life; the Earth

ecosystem

all the living organisms and nonliving things in a particular area

community

the array of organisms living in a particular ecosystem

population

all the individuals of a species within a specific area

organ systems

have specific functions and are composed of organs

organs

provide specific functions for the organism

tissues

made of groups of similar cells

molecules

clusters of atoms

atoms

the smallest unit of nonliving matter

organelles

membrane-bound structures with specific functions

cells

living entities distinguished from their environment by a membrane; the smallest unit of a living thing

DNA (deoxyribonucleic acid)

carries genetic information from one generation to the next

homeostasis

ability to maintain an internal environment consistent with life (common feature of life)

growth and development

consistent growth and development controlled by DNA (common feature of life)

response to the environment

an ability to respond to environmental stimuli (common feature of life)

hypothesis

proposed explanation for a set of observations, an educated guess.

reproduction

the ability to perpetuate the species (common feature of life)

theory

supported by a large and usually growing body of evidence

coarse adjustment

moves the stage up and down and brings an image into focus

fine adjustment

sharpens the image; produces a more detailed image

high power

high magnification; 40x

low power

low magnification; 10x

metric system

international system of measurements, based on powers of 10

SI

metric system

ocular

eyepiece

compound light microscope

uses light to magnify a specimen

Spontaneous Generation

Theory that stated that living things can arise from nonliving matter

atom

the basic unit of matter

nucleus

the center of an atom, which contains the protons and neutrons; in cells, structure that contains the cell's genetic material in the from of DNA

electron

negatively charged particle; located in the space surrounding the nucleus

element

pure substance that consists entirely of one type of atom

isotope

one of several forms of a single element, which contains the same number of protons but different numbers of neutrons

compound

substance formed by the chemical combination of two or more elements in definite proportions

ionic bond

chemical bond formed when one or more electrons are transferred from one atom to another

ion

atom that has a positive or negative charge

covalent bond

type of bond between atoms in which the electrons are shared

molecule

smallest unit of most compounds that displays all the properties of that compound

van der Waals forces

slight attraction that develops between oppositely charged regions of nearby molecules

hydrogen bond

weak attraction between a hydrogen atom and another atom

cohesion

attraction between molecules of the same substance

adhesion

force of attraction between different kinds of molecules

mixture

material composed of two or more elements or compounds that are physically mixed together but not chemically combined

solution

type of mixture in which all the components are evenly distributed

solute

substance that is dissolved in a solution

solvent

dissolving substance in a solution

suspension

mixture of water and non-dissolved material

pH scale

scale with values from 0 to 14, used to measure the concentration of H+ ions in a solution; a pH of 0 to 7 is acidic, a pH of 7 is neutral, and a pH of 7 to 14 is basic

acid

compound that forms hydrogen ions (H+) in solution; a solution with a pH of less than 7

base

compound that produces hydroxide ions (OH-) in solution; solution with a pH of more than 7

buffer

compound that prevents sharp, sudden changes in pH

monomer

small chemical unit that makes up a polymer

polymer

macro-molecules composed of many monomers; makes up macro-molecules

carbohydrate

compound made up of carbon, hydrogen, and oxygen atoms; type of nutrient that is the major source of energy for the body

monosaccharide

simple sugar molecule

lipid

macro-molecule made mostly from carbon and hydrogen atoms; includes fats, oils, and waxes

nucleic acid

macro-molecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus; carbon compound that stores and transmits genetic information

nucleotide

monomer of nucleic acid; sub-unit of which nucleic acids are composed; made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base

protein

macro-molecule that contains carbon, hydrogen, oxygen, and nitrogen; needed by the body for growth and repair

amino acid

monomer of protein; compound with an amino group on one end and a carboxyl group on the other end

chemical reaction

a process that changes, or transforms, one set of chemicals into another

reactant

elements or compounds that enter into a chemical reaction

product

elements or compounds produced by a chemical reaction

activation energy

energy that is needed to get a reaction started

catalyst

substance that speeds up the rate of a chemical reaction

enzyme

protein catalyst that speeds up the rate of a specific biological reactions

substrate

reactant of an enzyme-catalyzed reaction

proton

positively charged subatomic particle

amino acid

an organic molecule containing a carboxyl group and an amino group; serves as the monomer of proteins

amino group

in an organic molecule, a functional group consisting of a nitrogen atom bonded to two hydrogen atoms

carbohydrate

member of the class of biological molecules consisting of simple single-monomer sugars (disacchardies) and other multi-unit sugars (polysaccharides)

carbon skeleton

the chain of carbon atoms that forms the structural backbone of an organic molecule

carbonyl group

in an organic molecule, a functional group consisting of a carbon atom linked by a double bond to an oxygen atom

carboxyl group

in an organic molecule, a functional group consisting of an oxygen atom double-bonded to a carbon atom that is also bonded to a hydroxyl group

cellulose

a large polysaccharide composed of many glucose monomers linked into cable-like fibrils that provide structural support in plant cell walls

cholesterol

a steroid that is an important component of animal cell membranes and that acts as a precursor molecule for teh synthesis of other steroids such as hormones

dehydration reaction

a chemical process in which two molecules become covalently bonded to each other with the removal of a water molecule. condensation.

denaturation

a process in which a protein unravels, losing its specific structure and hence function; can be caused by changes in pH or salt concentration or by high temperature

DNA

a double-stranded helical nucleic acid molecule consisting of nucletide monomers with deoxyribose sugar and the nitrogenous bases A, C, G, T.

disaccharide

a sugar molecule consisting of two monosaccharides linked by a dehydration reaction

enzyme

a protein that serves as a biological catalyst changing the rate of a chemical rection without itself being changed into a different molecule in the process

fat

a large lipid molecule made from an alcohol called glycerol and 3 fatty acides; a triglyceride. Most fats function as energy storage molecules.

functional group

an assemblage of atoms commonly attached to the carbon skeletons of organic molecules and usually involved in chemical reactions

gene

a discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA

glycogen

an extensively branched polysaccharide of many glucose monomers

hydrocarbon

a chemical compound composed only of the elements carbon and hydrogen

hydrolysis

a chemical process in which polymers are broken down by the chemical adition of water molecules to the bonds linking their monomers; need for digestion

hydrophilic

"water loving"; pertaining to nonpolar molecules that don't dissolve in water

hydrophobic

"water fearing" pertaining to polar, or charged, molecules that are soluble in water

hydroxyl group

in an organic molecule, a functional group consisting of a hydrogen atom bonded to an oxygen atom

isomers

organic compounds with the same molecular formula but different structures and therefore different properties

lipid

an organic compound consisting mainly of carbon and hydrogen atoms linked by nonpolar convalent bonds, making the compound mostly hydrophobic