Human Biology Exam 1 - Chapters 1-3
Questions and Answers
isotope - ANSWER-when an atom of an element has a different number of neutrons
radioisotope - ANSWER-isotope with an unstable nucleus that becomes stable by
emitting energy and particles (process is known as radioactive decay)
tracer - ANSWER-molecule with a detectable substance such as a radioisotope
attached to it
number of electrons in 1st and 2nd shells? - ANSWER-2 e-, 8 e-
molecule - ANSWER-structure that is formed when chemical bonding joins atoms
mixture - ANSWER-two or more kinds of molecules mingle in varying proportions
covalent bond - ANSWER--atoms share two electrons
-bond forms when two atoms each have a lone electron in their outer shell and each
atom's attractive force pulls on the other's unpaired electron
-extremely stable
hydrogen bond - ANSWER-weak attraction between a covalently bound hydrogen
atom and an electronegative atom in a different molecule or in another part of the
same molecule
biological molecules - ANSWER-molecules that contain carbon and that are formed
in living things
ionic bond - ANSWER-association of two ions that have opposite charges
hydrophilic - ANSWER-chemically attracted to water
hydrophobic - ANSWER-chemically repelled by water
what are the chemical properties of water that help support life? - ANSWER--water
molecule is polar. it's oxygen atom is slightly positive and its hydrogen atoms are
slightly negative
-polarity allows water molecules to form hydrogen bonds with one another and with
other polar (hydrophilic) substances
-water molecules tend to repel nonpolar (hydrophobic) substances
-the hydrogen bonds in water help it stabilize temperature in body fluids and allow it
to dissolve many substances
solvent - ANSWER-means ions and polar molecules easily dissolve in it (ex. water is
a superb solvent)
, acid - ANSWER-substance that donates protons (as H+) to other solutes or to water
molecules when it dissolves water
base - ANSWER-substance that accepts H+ when it dissolves in water
hydrogen ion - ANSWER-proton (H+)
hydroxide ion - ANSWER-negatively charged molecule OH-
pH scale - ANSWER-measure of the concentration of H+ in a liquid
salts - ANSWER-compounds that release ions other than H+ and OH- in solutions
buffer - ANSWER-chemical that can stabilize the pH of a solution by donating or
accepting hydrogen ions (H+)
condensation reaction - ANSWER-chemical reaction that covalently bonds two
molecules into a larger one. Water often forms as a by-product
enzyme - ANSWER-type of protein that speeds up chemical reactions
functional group - ANSWER-atom or atoms bonded to carbon in a molecule that
helps determine the molecule's chemical properties
hydrolysis reaction - ANSWER-chemical reaction that splits a large molecule (a
molecule)
monomer - ANSWER-small subunit of a larger molecule
organic compound - ANSWER-compound that contains carbon and at least one
hydrogen atom
polymer - ANSWER-a large molecule built of monomer subunits
carbohydrate - ANSWER-biological molecule built of carbon, hydrogen, and oxygen
atoms, usually in a 1:2:1 ratio
monosaccharide - ANSWER-simplest class of carbohydrate, consisting of a single
sugar monomer. A glucose molecule is an example
oligosaccharaide - ANSWER-a carbohydrate that consists of a short chain of sugar
units. sucrose is an example
polysaccharide - ANSWER-complex carbohydrate that consists of straight or
branched chains of sugar monomers. cellulose is an example
fat - ANSWER-lipid molecule that has up to three fatty acid tails
fatty acid - ANSWER-chemical compound with a backbone of carbon atoms bonded
to a carboxyl group
Questions and Answers
isotope - ANSWER-when an atom of an element has a different number of neutrons
radioisotope - ANSWER-isotope with an unstable nucleus that becomes stable by
emitting energy and particles (process is known as radioactive decay)
tracer - ANSWER-molecule with a detectable substance such as a radioisotope
attached to it
number of electrons in 1st and 2nd shells? - ANSWER-2 e-, 8 e-
molecule - ANSWER-structure that is formed when chemical bonding joins atoms
mixture - ANSWER-two or more kinds of molecules mingle in varying proportions
covalent bond - ANSWER--atoms share two electrons
-bond forms when two atoms each have a lone electron in their outer shell and each
atom's attractive force pulls on the other's unpaired electron
-extremely stable
hydrogen bond - ANSWER-weak attraction between a covalently bound hydrogen
atom and an electronegative atom in a different molecule or in another part of the
same molecule
biological molecules - ANSWER-molecules that contain carbon and that are formed
in living things
ionic bond - ANSWER-association of two ions that have opposite charges
hydrophilic - ANSWER-chemically attracted to water
hydrophobic - ANSWER-chemically repelled by water
what are the chemical properties of water that help support life? - ANSWER--water
molecule is polar. it's oxygen atom is slightly positive and its hydrogen atoms are
slightly negative
-polarity allows water molecules to form hydrogen bonds with one another and with
other polar (hydrophilic) substances
-water molecules tend to repel nonpolar (hydrophobic) substances
-the hydrogen bonds in water help it stabilize temperature in body fluids and allow it
to dissolve many substances
solvent - ANSWER-means ions and polar molecules easily dissolve in it (ex. water is
a superb solvent)
, acid - ANSWER-substance that donates protons (as H+) to other solutes or to water
molecules when it dissolves water
base - ANSWER-substance that accepts H+ when it dissolves in water
hydrogen ion - ANSWER-proton (H+)
hydroxide ion - ANSWER-negatively charged molecule OH-
pH scale - ANSWER-measure of the concentration of H+ in a liquid
salts - ANSWER-compounds that release ions other than H+ and OH- in solutions
buffer - ANSWER-chemical that can stabilize the pH of a solution by donating or
accepting hydrogen ions (H+)
condensation reaction - ANSWER-chemical reaction that covalently bonds two
molecules into a larger one. Water often forms as a by-product
enzyme - ANSWER-type of protein that speeds up chemical reactions
functional group - ANSWER-atom or atoms bonded to carbon in a molecule that
helps determine the molecule's chemical properties
hydrolysis reaction - ANSWER-chemical reaction that splits a large molecule (a
molecule)
monomer - ANSWER-small subunit of a larger molecule
organic compound - ANSWER-compound that contains carbon and at least one
hydrogen atom
polymer - ANSWER-a large molecule built of monomer subunits
carbohydrate - ANSWER-biological molecule built of carbon, hydrogen, and oxygen
atoms, usually in a 1:2:1 ratio
monosaccharide - ANSWER-simplest class of carbohydrate, consisting of a single
sugar monomer. A glucose molecule is an example
oligosaccharaide - ANSWER-a carbohydrate that consists of a short chain of sugar
units. sucrose is an example
polysaccharide - ANSWER-complex carbohydrate that consists of straight or
branched chains of sugar monomers. cellulose is an example
fat - ANSWER-lipid molecule that has up to three fatty acid tails
fatty acid - ANSWER-chemical compound with a backbone of carbon atoms bonded
to a carboxyl group
