Chapter 2- The Chemistry of Life Flashcards
What are the subatomic particles that make up atoms?
protons, neutrons, and electrons
What are the main types of chemical bonds?
covalent and ionic bonds
What is the basic unit of matter?
atom
What is at the center of the atom?
a nucleus that contains protons and neutrons that are bind together by strong forces
What is an electron?
a negatively charged particle (-) with 1/1840 the mass of a proton; constantly in motion, surrounding the nucleus; attracted to the positively charged nucleus
What is a proton?
positively charged particles (+)
What is a neutron?
particles that carry no charge
Why are all atoms neutral?
because there is an equal number of protons and electrons
What is a chemical element?
a pure substance that consists entirely of one type of atom
What are isotopes?
atoms of the same element that differ in the number of neutrons they contain
What is the atomic number?
the number of protons in an element
What is the atomic mass?
of protons + # of neutrons
What is a chemical compound?
a substance formed by the chemical combination of 2 or more elements in definite proportions (NaCl)
What is an ionic bond?
one or more electrons are transferred from one atom to another
What are ions?
positively or negatively charged atoms
What is a covalent bond?
when electrons are shared between atoms (water)
What are van der Waals forces?
when molecules are together, a slight attraction can develop between the oppositely charged regions of nearby molecules; not as strong as ionic or covalent bonds
Why is a water molecule polar?
because there is an uneven distribution of electrons between the oxygen and hydrogen atoms
What do acidic solutions have more of than water?
concentration of H+ ions
What are the pH values for acidic solutions?
0<7
What do basic solutions have less of than water?
concentration of H+ ions
What are the pH values of basic solutions?
7<14
What happens to water when it freezes?
it expands making them less dense
What is cohesion?
an attraction between molecules of the same substance
What is adhesion?
an attraction between molecules of different substances
What is a mixture?
a material composed of 2 or more elements or compounds that are PHYSICALLY mixed together but not chemically combined
What is a solution?
A mixture of 2 or more substances in which all substances are evenly distributed
What is a solute?
the solid substance being dissolved
What is a solvent?
the liquid substance that dissolves the solute
What is a suspension?
mixture of water and non-dissolved material (blood & orange juice)
What is the pH scale?
a measurement system that indicates the concentration of H+ ions in a solution
What are buffers?
weak acids or bases that can react with strong acids and bases to prevent sharp, sudden changes in pH
What are the 4 organic compounds found in living things?
carbohydrates, lipids, nucleic acids, and proteins
What do living things use carbohydrates for?
Their main source of energy; some use it for structural purposes
What are lipids used for?
to store energy; some are important parts of biological membranes and waterproof coverings
What do nucleic acids do?
store and transmit hereditary, or genetic information
What do proteins do?
- control rate of reactions
- regulate cell processes
- build tissues (bone and muscle)
- transport materials
- help fight disease
What are macromolecules?
giant molecules
What is polymerization?
the process where large compounds are built by joining smaller ones together
What are monomers and polymers?
Monomers are the smaller units that join together to form polymers
What are carbohydrates?
compounds made up of carbon, hydrogen, and oxygen atoms (1:2:1)
What are monosaccharides? List some examples.
single sugar molecules; ex. glucose, galactose, and fructose
What are polysaccharides? Give examples.
large macromolecules formed from monosaccharides; ex. glycogen (animal starch) and cellulose
What are lipids? What are its common categories?
made mostly from carbon and hydrogen atoms; it is not soluble; common categories: fats, oils, and waxes
What does it mean when a fatty acid is unsaturated?
there is at least one carbon-carbon double bond
What does it mean when a fatty acid is polyunsaturated?
fatty acids that contain more than one carbon double bond
What are nucleic acids?
Macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorous.
What are nucleotides? What are their three parts?
monomers of nucleic acids; a 5-carbon sugar, a phosphate group, and a nitrogen base
What are the two kinds of nucleic acids?
ribonucleic acid (RNA) and deoxyribonucleic acid (DNA)
What are proteins?
macromolecules that contain nitrogen, carbon, hydrogen, and oxygen; polymers of amino acids; most diverse of macromolecules b/c of shape and arrangement
Where are the instructions for the arrangements of proteins found?
DNA
What is a chemical reaction?
a process that changes, or transforms, one set of chemicals into another; mass and energy are conserved
What are reactants?
elements or compounds that enter into a chemical reaction
What are products?
the elements or compounds produced by a chemical reaction
What is activation energy?
the energy that is needed to get a reaction started
What is a catalyst?
a substance that speeds up the rate of a chemical reaction; they work by lowering a reaction’s activation energy
What are enzymes?
proteins that act as biological catalysts; very specific
What are substrates?
reactants of enzyme-catalyzed reactions
Chemical reactions always involve changes in what?
in the chemical bonds that join atoms in compounds
How do chemical reactions that release energy occur? (exothermic)
spontaneously-natural & uninhibited manner
How will a chemical reaction that absorb energy (endothermic) occur?
With a source of energy (most organisms use endothermic reactions since they need a source of energy )
What are active sites?
sites in enzymes where reactants (substrates) can bind to
