56 terms

Matter and atoms Ch. 2 Miller & Levine

Biology 1 Chapter 2 Miller & Levine
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atom
basic unit of matter; neutral charge, made up of protons, neutrons, and electrons
nucleus
the center of the atom where protons and neutrons are located
electron
negatively charged atomic particles; are in constant motion around the nucleus
proton
positively charged atomic particles; located at the center of an atom
neutron
atomic particles with no charge; located at the center of an atom
element
a chemically pure substance with only one type of atom
isotope
atoms of the same element that differ in the number of neutrons
compound
a substance formed by the combination of two or more elements in definite proportions
ionic bond
formed when two or more electrons are transferred from one atom to another; between a metal and a non-metal
ions
positively or negatively charged atoms
covalent bond
the sharing of electrons by atoms; between two metals
molecule
smallest unit of most compounds; formed by covalent bond
van der Waals forces
intermolecular forces of attraction formed by oppositely charged regions of nearby molecules
hydrogen bond
the attraction between a hydrogen atom with a partial positive charge and an atom with a partial negative charge
cohesion
attraction between molecules of the same substance
adhesion
an attraction between molecules of different substances
solution
a type of mixture where all components are evenly distributed
solute
substance that is dissolved in a solution
solvent
substance in which another substance is dissolved in a solution
suspension
mixtures of water and nondissolved materials
pH scale
measurement system developed to indicate the concentration of hydrogen ions in a solution
acid
Any compound that forms H+; pH of less than 7; contains higher concentration of hydrogen atoms than water
base
A compound that produces OH- ions in solution; pH greater than 7; contains higher concentration of hydroxide ions. (alkaline)
buffers
weak acids or bases that can react with stronger acids or bases to prevent sudden, sharp changes in pH
monomers
small chemical unit that makes up a polymer
polymers
molecules composed of many monomers; makes up macromolecules
carbohydrates
compounds made up of carbon, hydrogen, and oxygen atoms- usually in a ratio of 1:2:1; main source of energy for living organisms
lipids
mostly made of carbon and hydrogen atoms; commonly called fats, oils or waxes; can be used to store energy
nucleic acids
macromolecules containing hydrogen, oxygen, carbon, and phosphorus
nucleotides
consist of a 5-carbon sugar, a phosphate group, and a nitrogen base, the monomer unit of nucleic acids
proteins
macromolecules that contain nitrogen as well as carbon, hydrogen, and oxygen
amino acids
compounds with an amino group on one end and a carboxyl group on the other end, these are monomers of protein
chemical reaction
the process that changes or transforms one set of chemicals into another
reactants
elements or compounds that enter into a chemical reaction; input
products
elements or compounds produced in a chemical reaction; outcome
activation energy
the energy that is needed to get a reaction started
catalyst
substance that speeds the rate of the reaction process
enzymes
proteins that act as biological catalysts; speed up chemical reactions that take place in cells
monosaccharides
single sugar molecules (glucose, galactose, or fructose for example)
mixture
A material composed of two or more elements or compounds that are physically mixed together but not chemically combined
polysaccharides
Large macromolecules formed from monosaccharides--sugar molecules
(RNA) ribonucleic acid
single-stranded nucleic acid that contains the sugar ribose
(DNA) deoxyribonucleic acid
nucleic acid that contains the sugar deoxyribose
substrates
The reactants of enzyme-catalyzed reactions
valence electrons
electrons in the outer shell of an atom, these are the electrons that can form bonds
If carbon has 4 valence electrons how many bonds can it form?
four
In a water molecule what is the charge of the hydrogen atoms?
slightly positive
The oxygen atom in water has what charge?
slightly negative
Chemical reaction that release energy
are spontaneous reactions
spontaneous reactions
are reactions that will occur without the addition of energy (they release energy during the reaction)
What chemicals are abbreviated C, H, O, N
carbon, hydrogen, oxygen, nitrogen
What is the chemical formula for table salt?
NaCl
What is the chemical formula for water?
H20
What is the chemical formula for hydrochloric acid?
HCl
How many bonds can a carbon atom make?
4
Solutions with more H+ than OH- are what?
acidic