AP-Bio units 1-5

For Midterms

Biology

science of life

Biologist

a scientist who studies living things

Organism

A living thing

Gene

unit of heredity

Genome

genetic information that an organism contains

Cell

simplest self-reproducing unit that can exist independently

Species

group of interbreeding organisms that produce fertile offspring

Evolution

change over time

Natural Selection

some individuals survive and reproduce more than others in a particular environment as a result of variation among individuals that can be passed down to next generation

Energy

the ability to do work

Energetics

the flow of energy and its changes from one form to another

Deoxyribonucleic acid - DNA

carrier of genetic information for all organisms

System

group of things that function together as a whole

Abiotic

non-living components of an environment

Biotic

living organisms

Biological System

made up of both biotic and abiotic entities that interact

Scientific Inquiry

the process scientists use to ask questions and seek answers about the world in a deliberate and ordered way

Observation

the action or process of observing something or someone carefully or in order to gain information.

Hypothesis

A testable prediction, often implied by a theory

Controlled Experiment

An experiment in which only one variable is manipulated at a time.

Test Group/experimental group

experiences the variable

Control Group

the group that does not receive the experimental treatment.

Independent Variable

variable that is manipulated

dependent variable

The outcome factor; the variable that may change in response to manipulations of the independent variable.

negative control group

group where there should not be an effect

positive control group

group where an effect is expected

null hypothesis

the hypothesis that there is no significant difference between specified populations, any observed difference being due to sampling or experimental error.

alternative hypothesis

The hypothesis that states there is a difference between two or more sets of data.

matter

Anything that has mass and takes up space

atom

Basic unit of matter

molecule

two or more atoms held together by covalent bonds

organic molecule

A molecule containing carbon that is a part of or produced by living systems.

nucleus

Control center of the cell

proton

positively charged particle

neutron

no charge

electron

negatively charged particle

atomic number

number of protons

element

A substance that cannot be broken down into simpler substances

atomic mass

Number of protons and neutrons - total mass of atom

isotope

Atoms of the same element that have different numbers of neutrons

ion

A charged atom

energy level/electron shell

where electrons circle around the nucleus

valence electron

Electrons on the outermost energy level of an atom

periodic table of elements

A table that classifies elements by their physical and chemical properties; rows are called periods; columns are called groups

chemical bond

the force that holds two atoms together

covalent bond

A chemical bond that involves sharing a pair of electrons between atoms in a molecule

single bond

A pair of shared electrons

double bond

A covalent bond in which two pairs of electrons are shared between two atoms

electronegativity

the ability of an atom to attract electrons

polar covalent bond

unequal sharing of electrons

nonpolar covalent bond

equal sharing of electrons

ionic bond

Formed when one or more electrons are transferred from one atom to another

chemical reaction

process that changes one set of chemicals into another set of chemicals

reactant

A chemical substance that is present at the start of a chemical reaction

product

A substance produced in a chemical reaction

polymer

molecules composed of many monomers; makes up macromolecules

monomer

A simple compound whose molecules can join together to form polymers

protein

An organic compound that is made of one or more chains of amino acids and that is a principal component of all cells - contains N, C, H, O, and sometimes sulfur

amino acid

Building blocks of protein

nucleic acid

macromolecule containing hydrogen, oxygen, nitrogen, carbon, and phosphorus

ribonucleic acid - RNA

single-stranded nucleic acid that contains the sugar ribose

nucleotide

A building block of DNA, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and a phosphate group.

carbohydrate

compound made up of carbon, hydrogen, and oxygen atoms; major source of energy for the human body

lipid

macromolecule made mostly from carbon and hydrogen atoms; includes fats, oils, and waxes

hydrophobic

Water fearing

hydrophilic

water loving

polar

Molecule with partial charges. Mixes with water.

hydrogen bond

Attraction between a slightly positive hydrogen atom and a slightly negative atom.

cohesion

Attraction between molecules of the same substance

adhesion

An attraction between molecules of different substances

surface tension

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

specific heat

the heat required to raise the temperature of the unit mass of a given substance by a given amount

solvent

the substance in which the solute dissolves

acid

any compound that forms H+ ions in solution - low #

base

A substance that decreases the hydrogen ion concentration in a solution - high #

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

dehydration synthesis/condensation reaction

a chemical reaction in which two or more molecules combine resulting in the loss of a water molecule - makes molecule bigger

hydrolysis reaction

A chemical reaction that breaks apart a larger molecule by adding a molecule of water

functional group

A specific configuration of atoms commonly attached to the carbon skeletons of organic molecules and involved in chemical reactions.

ribose

sugar in RNA

deoxyribose

sugar in DNA

disaccharide

A double sugar, consisting of two monosaccharides joined by dehydration synthesis.

polysaccharide

Carbohydrates that are made up of more than two monosaccharides

complex carboyhydrate

long branched chains of monosaccharides

cell membrane

thin, flexible barrier around a cell; regulates what enters and leaves the cell

plasma membrane

A selectively-permeable phospholipid bilayer forming the boundary of the cells

triacylglycerol

three fatty acids linked to one glycerol molecule

glycerol

Combines with fatty acids to make lipids.

fatty acid

Building Blocks of Lipids

saturated vs unsaturated fatty acid

a) saturated - no carbon double bond ~ straight

b) unsaturated - at lease one carbon double bond ~ bends

van der waal force

attraction force between the positive region on one molecule and the negative region on another molecule - weak

steriod

A lipid that is composed of 4 fused carbon rings, commonly found in cell membranes.

peptide bond

The chemical bond that forms between the carboxyl group of one amino acid and the amino group of another amino acid

polypeptide

A polymer (chain) of many amino acids linked together by peptide bonds.

primary structure

sequence of amino acids

secondary structure

Either an alpha helix or beta pleated sheet.

tertiary structure

the overall, three-dimensional shape of a polypeptide due to interactions of the R groups of the amino acids making up the chain.

quaternary structure

the shape resulting from the association of two or more polypeptide subunits.

alpha helix

the spiral shape resulting from the coiling of a polypeptide in a protein's secondary structure