AP Biology Summer Assignment Unit 1

Hypothesis

A testable prediction

scientific law

A statement that describes what scientists expect to happen every time under a particular set of conditions

scientific theory

a well-tested concept that explains a wide range of observations

Constants

Conditions that stay the same in the experiment

control group

In an experiment, the group that is not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment.

experimental group

In an experiment, the group that is exposed to the treatment, that is, to one version of the independent variable.

dependent variable

The measurable effect, outcome, or response in which the research is interested.

independent variable

The experimental factor that is manipulated; the variable whose effect is being studied.

mean

average

Median

the middle score in a distribution; half the scores are above it and half are below it

range

the difference between the highest and lowest scores in a distribution

Mode

the most frequently occurring score(s) in a distribution

Matter

Anything that has mass and takes up space

Element

A pure substance made of only one kind of atom

Compound

A substance made up of atoms of two or more different elements joined by chemical bonds

chemical bonds

the attractive forces that hold atoms together

Hydrogen bonds

attractive forces in which a hydrogen covalently bonded to a very electronegative atom is also weakly bonded to an unshared electron pair of another electronegative atom

covalent bond

Bond created by sharing electrons with other atoms.

ionic bond

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

water

H2O; solvent found in living things and many biological systems

polar molecule

molecule with an unequal distribution of charge, resulting in the molecule having a positive end and a negative end

non-polar molecule

molecule that shares electrons equally and does not have oppositely charged ends

Cohesion

Attraction between molecules of the same substance

Adhesion

An attraction between molecules of different substances

Electronegativity

A measure of the ability of an atom in a chemical compound to attract electrons

atomic mass

Number of protons and neutrons

Solute

A substance that is dissolved in a solution.

Solvent

A liquid substance capable of dissolving other substances

Solution

A homogeneous mixture of two or more substances

valence electrons

Electrons on the outermost energy level of an atom

Molecule

two or more atoms held together by covalent bonds

Acid

A substance that increases the hydrogen ion concentration of a solution.

Base

A substance that decreases the hydrogen ion concentration in a solution.

pH

measurement system used to indicate the concentration of hydrogen ions (H+) in solution; ranges from 0 to 14

ATP

(adenosine triphosphate) main energy source that cells use for most of their work

Macromolecule

large molecule formed by joining smaller organic molecules together

Monomer

A simple compound whose molecules can join together to form polymers

Polymer

A long molecule consisting of many similar or identical monomers linked together.

Carbohydrate

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

Monosaccharide

A single sugar molecule such as glucose or fructose, the simplest type of sugar.

Disaccharide

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

Polysaccharide

large macromolecule formed from monosaccharides

Starch

A storage polysaccharide in plants consisting entirely of glucose.

Amino Acid

Building blocks of protein

Peptide Bond

covalent bond formed between amino acids

Polypeptide

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

Hydrophobic

"Water-fearing"; pertaining to nonpolar molecules (or parts of molecules) that do not dissolve in water.

Hydrophilic

Having an affinity for water.

Lipid

Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen.

fat

A large lipid molecule made from an alcohol called glycerol and three fatty acids; a triglyceride. Most fats function as energy-storage molecules.

Fatty Acid

hydrocarbon chain often bonded to glycerol in a lipid

Phospholipid

a lipid that contains phosphorus and that is a structural component in cell membranes

Protein

A three dimensional polymer made of monomers of amino acids.

Denature

A change in the shape of a protein (such as an enzyme) that can be caused by changes in temperature or pH (among other things).

DNA

A complex molecule containing the genetic information that makes up the chromosomes.

RNA

single-stranded nucleic acid that contains the sugar ribose

Nucleotide

monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base

Antiparallel

The opposite arrangement of the sugar-phosphate backbones in a DNA double helix.

Nucleic Acid

macromolecule containing hydrogen, oxygen, nitrogen, carbon, and phosphorus; DNA and RNA

Gene

A segment of DNA on a chromosome that codes for a specific trait