AP Biology unit 1.1 and 1.2 study guide
which property of water allows dogs to cool themselves by panting
waters' high heat of vaporization
Solvent
A liquid substance capable of dissolving other substances
polymer
A long molecule consisting of many similar or identical monomers linked together.
surface tension
A measure of how difficult it is to stretch or break the surface of a liquid
monomer
A simple compound whose molecules can join together to form polymers
Base
A substance that decreases the hydrogen ion concentration in a solution.
Acid
A substance that increases the hydrogen ion concentration of a solution.
enzyme
A type of protein that speeds up a chemical reaction in a living thing
Macromolecules
A very large organic molecule composed of many smaller molecules
Why does water have a high specific heat?
a water molecule can maek 4 hydrogen bonds
which property of water allows a paper towel to pick up a puddle of water
adhesion of water molecules to other kinds of molecules
which statement is true of water's tensile strength
it results from hydrogen bonding, helps water through plants, involves cohesion and adhesion
the temperature of boiling water remains constant because
it takes energy to break hydrogen bonds
covalent bond
A chemical bond that involves sharing a pair of electrons between atoms in a molecule
dehydration synthesis
A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule.
polar covalent bond
A covalent bond in which electrons are not shared equally
Look at the figure showing the pH values of some familiar aqueous solutions. What is the difference between H+ concentration in an acidic solution such as lemon juice (pH 2) and a basic solution such as household bleach (pH 13)?
The H+ concentration of lemon juice is higher than the H+ concentration of household bleach by a factor of 1011 (100 billion).
heat of vaporization
The amount of energy required for the liquid at its boiling point to become a gas
specific heat
The amount of energy required to raise the temperature of 1 gram of a substance by 1 degree celcius
The unequal sharing of electrons within a water molecule makes the water molecule _____.
polar
what bond is found between oxygen and hydrogens
polar covalent
why amphipathic molecules line up at a water surface?
polar groups attract one another
cohesion
the atrraction between like molecules
Hydrolysis
the chemical breakdown of a compound due to reaction with water.
functional groups
the components of organic molecules that are most commonly involved in chemical reactions
heat capacity
the number of heat units needed to raise the temperature of a body by one degree.
electronegative
the tendency to attract electrons to form a chemical bond
interactions between atoms that result in polar covalent bonds
two atoms of different electronegativity share two electrons unequally
relate the heat capacity of water to the ability of organisms to maintain internal temperature
water has a high specific heat capacity, high amounts of energy are needed to break H bonds and change temp of water
Describe the circumstances in which water may behave as a solvent vs. when water is not able to act as a solvent.
water is only able to dissolve hydrophillic and polar, can't dissolve hydrophobic and nonpolar substances
A dehydration reaction is the process in which __________.
water molecules are produced as a polymer is formed from monomers
why is ice less dense than liquid water
water molecules make hydrogen bonds at definite angles and cold molecules move less than warm molecules
ATP
(adenosine triphosphate) main energy source that cells use for most of their work
adhesion
An attraction between molecules of different substances
Cohesion
Attraction between molecules of the same substance
what elements are found in macromolecules
CHNOPS
hydrocarbon
Compounds composed of only carbon and hydrogen
organic compound
Compounds that contain carbon
difference between ionic bonds and covalent bonds
Electrons are exchanged between atoms held together by an ionic bond, but they are shared between atoms held together by a covalent bond
ionic bond
Formed when one or more electrons are transferred from one atom to another
Why doesn't oil mix with water?
Polar molecules attract one another.
evaporative cooling
The process in which the surface of an object becomes cooler during evaporation, a result of the molecules with the greatest kinetic energy changing from the liquid to the gaseous state.
Hydrophobic
Water fearing
nonpolar covalent bond
a covalent bond in which the electrons are shared equally by the two atoms
dissolving is best described as
a mingling of molecules and/or ions.
Explain the importance of adhesion and cohesion to living systems.
allow for capillaru action and surface tension
The open spaces in water's crystal structure make it possible for ...
aquatic life to exist at the north pole
____ and ____ from the environment are necessary to build new molecules
atoms and molecules
importance of carbon atom as a building block of life over the other elements in biomolecules
can form covalent bonds to as many as four different atoms
The large diversity of shapes of biological molecules is possible because of the extensive presence of _____ in the molecules
carbon
the hydrogen bonds between water molecules result in ____ , ____, and ____ ____
cohesion, adhesion, surface tension
buffer
compound that prevents sharp, sudden changes in pH
What is another name for a condensation reaction?
dehydration
hydrophillic molecules
dissolve in water
why are hydrogen bonds weaker than covalent bonds
do not involve sharing of electrons
the tendency of an atom to pull electrons toward itself is referred to as its ___
electronegativity
how do organisms obtain raw materials to grow and live
food, water, oxygen, energy from other plants and animals
relationship bewteen the molecular structure of water and its properties of adhesion, cohesion, and surface tension and to the behavior of water as a solvent
form hydrogen bonds with other polar substanes, H20 molecules, resist disruption of surface when under sress, dissolve hydrophilic substances due ot its polarity
A water molecule can bond to up to _____ other water molecules by ____ bonds.
four... hydrogen
Explain the importance of buffers to biological systems.
help system maintain pH and constant environment
Because organisms are made primarily of water, they resist rapid temperature changes. This useful quality is based on water's _____
high specific heat
what bond is weaker
hydrogen
Water is a source of ______________ for chemical reactions in cells.
hydrogen and oxygen atoms
Water molecules have a polarity, which allows them to be electrically attracted to other water molecules and other polar molecules by weak chemical bonds known as _____.
hydrogen bonds
random collisions allow some molecules to accumulate more energy than other molecules. The weakness of the ________ lets those molecules escape, leaving the cooler ones behind.
hydrogen bonds
when you heat water, much of the heat is used to break _____
hydrogen bonds
Water has surface tension because ...
hydrogen bonds between surface water molecules resist being stretched
where does surface tensions result from
hydrogen bonds formed between water molecules at the surface and between
What is the name of the process during which a bond between two monomers is broken?
hydrolysis
_____ and _____ are used to cleave and form covalanet bonds between monomers
hydrolysis, dehydration synthesis
Describe the implications of the different densities of frozen vs. liquid water to aquatic ecosystems.
ice= less sense, floats above liquid water
in hydrolysis, water goes __ and energy comes _____
in, out
what happens with remaining heat after hydrogen bonds are formed
increases molecular motion raising temperature
An acid is a substance that _____.
increases the hydrogen ion concentration of an aqueous solution
organisms must exchange ____ with the environment to grow, reproduce, and maintain organizaiton
matter
the subcomponents of biological molecules and their sequence determine the properties of that ___
molecule
which factor is important in making it possible to cool yourself by sweating
molecules collide with varied angles and speeds and hydrogen bonds are relatively weak
phosphorus is used to build ___ and ___
nucleic acids and certain lipids
in dehydration synthesis, water goes ___ and energy goes ___ -
out, in
living systems depend on properties of water that result from its _____ and ______ ____
polarity, hydrogen bonding
nitrogen is used to build ____ and ____
proteins and nucleic acids
parts of an atom
protons, neutrons, electrons
surface tension
resistance of the liquid to stretching or breaking.
what is a buffer
solutions made of an acid/base pair that minimize the effects of increasing H+ or OH-
carbon is used to build biological molecules such as carbohydrates, proteins, liqids, and nucleic acids. Carbon is used in ______ _____ and cell formation in all organisms
storage compounds
polarity and hydrogen bonding capabilities of functional groups
when 2 equally strong atoms are bound, sharing of electrons will be equal. if functional group has an atom that has strong-weak bonds, group will be polar