CP Biology unit 1-2 terms exam review

Independent variable

Independent variable

variable that is manipulated or changed (X)

Dependent variable

The outcome factor; the variable that is changed by the independent variable (Y)

Quantitive data

uses numbers to describe what is observed

Qualitative data

descriptive characteristics

DNA

molecule containing the genetic information

Theory

A hypothesis that has been tested with a significant amount of data

Characteristics of living things

Reproduce, respond to environment, grow and develop, composed by cells

Evolution

Change over time

controlled experiment

An experiment in which only one variable is changed.

Peer reviews

a process in which scientists examine other scientists' work

Atom

Basic unit of matter (neutral)

Nucleus

Center of an atom

Protons

positive charge (H+)

Neutrons

neutral charge

Electrons

negative charge

Element

A pure substance made of only one kind of atom

Isotopes

Atoms of the same element that have different numbers of neutrons

Compound

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

Ionic bond

the attraction between oppositely charged ions

covalent bond

A chemical bond formed when two atoms share electrons

Molecule

A group of atoms bonded together

van der Waals forces

a slight attraction that develops between the oppositely charged regions of nearby molecules

Why is water polar

Because it has positive and negative poles.

Hydrogen bond

weak attraction between a hydrogen atom and another atom (water forms many of these)

Cohesion

Attraction between molecules of the same substance

Adhesion

An attraction between molecules of different substances

capillary action

the attraction of the surface of a liquid to the surface of a solid

Mixture

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

Solute

A substance that is dissolved in a solution.

The greatest solvent in earth

Water (bc of its polarity)

Suspensions

mixtures of water and non dissolved material (sand in water)

Acids

pH below 7 and produces H+ ions

Bases

pH above 7 and produces hydroxide ions in solutions

Ph of water

7 (neutral)

Buffers

substances that minimize changes in pH

Polymerization

large compounds are built by joining smaller ones together smaller: monomers larger units: polymers

Carbohydrates

Broken down to simple sugars to provide energy and serve as structure

Simple sugars

monosaccharides

Monosaccharides

glucose, fructose, galactose

Polysaccharides

Carbohydrates that are made up of more than two monosaccharides (starch, cellulose, glycogen)

Lipids

fats and oils made of CHO (used to store energy)

nucleic acids

macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus. used to transmit hereditary or genetic information.

proteins

macromolecules that contain nitrogen, hydrogen and oxygen. made of amino acids

products

ENDING materials in a chemical reaction.

reactants

STARTING material in a chemical reaction

Chemical reaction

process that changes one set of chemicals into another

activation energy

Energy needed to get a reaction started

catalyst

substance that speeds up the rate of a chemical reaction

enzymes

Proteins that speed up chemical reactions, they are very specific

substrate

the reactants of enzyme-catalized reactions

factors that affect the function of an enzyme

temperature, PH and regulatory molecules