Chapter 2 Part 2. Flashcards
What are the unique properties of water?
(1) its virtuosity as a dissolving agent
(2) its high heat capacity
(3) its high heat of vaporization
(4) water molecules are cohesive (cling together)
(5) is adhesive (they cling to other molecules)
(6) is very interactive w/other elements
(7) is a solvent
(8) helps prevent dramatic changes in body temperature
Why is water able to prevent dramatic changes in body temperature?
high heat capacity and high heat of vaporization
Water’s unusual qualities can be traced to its _______
polarity
What is polarity?
the tendency of its molecules to have positive and negative regions and the hydrogen bonds between its molecules
Unequal covalent bonds are called ______
polar
What are polar molecules?
molecules with unevenly distributed charges
What is a hydrogen bond?
the attraction between a slightly positively charged hydrogen atom and a slightly negatively charged atom nearby
True or False: Hydrogen bonds are stronger than ionic and covalent bonds
False; Hydrogen bonds are weaker than ionic and covalent bonds
How are hydrogen bonds represented in a structural formula?
by dotted lines
What is the difference between acids and bases?
Acid- anything that releases hydrogen ions (H+) when placed in water
Base- anything that releases hydroxide ions (OH-) when placed in water
Acid _________ the concentration of H+ in solution
increases
_____ increases the concentration of H+ in solution
Acid
______ decrease the concentration of H+ in solution
Bases
Bases _________ the concentration of H+ in solution
decrease
What is pH?
a measure of hydrogen ion concentration within a solution
What is the pH scale?
ranges from 0 to 14
pH of 7 is _______
neutral
the lower the pH the more _______
acidic
What are buffers?
keep pH values form changing dramatically
What is acid precipitation?
rain, snow, or fog with a pH lower than 5.6 (the pH of natural precipitation)
What are the major causes of acid precipitation?
burning of fossil fuels in cars, factions, and power plants
What are some of the effects it can have on humans?
irritation and respiratory illnesses such as asthma and bronchitis
____ ___________ has been linked to the decline of forests, and to decreases in aquatic organisms
Acid precipitation
Acid precipitation has been linked to the decline of _______, and to decreases in _______ _________
forests
aquatic organisms
What are macromolecules?
exceptionally large molecules
What are polymers?
macromolecules that consist many small, repeating molecular subunits linked in a chain
How do polymers form?
through dehydration synthesis (aka condensation reaction)
What are monomers?
small molecular subunits that form the building blocks of the polymer
_________ requires the addition of water across the covalent bonds
Hydrolysis
What does the body use hydrolysis for?
to break many polymers apart
What are carbohydrates?
provide fuel (or energy) for the human body
Carbohydrates are also known as ______ and ________
sugars
starches
Carbohydrates are made entirely of ______, _______, and _______ with each molecule having twice as many hydrogen atoms as oxygen atoms
carbon
hydrogen
oxygen
Carbohydrates are made entirely of carbon, hydrogen, and oxygen with each molecule having twice as many ________ atoms as _______ atoms
hydrogen
oxygen
What are monosaccharides?
the smallest molecular units of carbohydrates
Monosaccharides are also known as _______ ______
simple sugars
What is pentose?
a sugar that contains 5 carbons
What is hexose?
a sugar that contains 6 carbons
What is a oligosaccharide?
chains of a few monosaccharides joined together by dehydration synthesis
Oligosaccharide:
_____= “few”
oligo
Oligosaccharide:
oligo= “____”
“few”
What is a disaccharide?
a type of oligosaccharide;
a double sugar that forms when two monosaccharides covalently bond to each other
What is a polysaccharide?
a complex carbohydrate that forms when monosaccharides (most commonly glucose) join together in long chains
What is the purpose of polysaccharides?
most store energy or provide structure
What is the storage polysaccharide called in plants and humans?
starch for plants
glycogen for humans
What is glycogen?
a short-term energy source that can be broken down to release energy-laden glucose molecules
What is cellulose?
a structural polysaccharide found in the cell walls of plants
