Chapter 3: Water and Life
Which statement helps to explain why ice is less dense than liquid water?
(a) Water molecules make hydrogen bonds at definite angles. (b) Cold molecules move less than warm molecule
Polar attractions are ...
(a) forces between atoms with partial charges. (b) weaker than covalent bonds. (c) important because they are numerous.
Water is a source of ______________ for chemical reactions in cells
(a) hydrogen atoms (b) oxygen atoms
-Acid adds [H+] to a solution and removes OH- because of the tendency to for H+ to combine with OH- to form water. -Bases increase OH- and reduces H+ by forming water.
**This constant relationship expresses the behavior of acids and bases in an aqueous solution.
Properties of water essential to life
- Water is Cohesive and Adhesive - Water has High specific Heat - Water has a high boiling point - Water is a good evaporative coolant - Water has a higher density as a liquid than as a solid - Water is an excellent Solvent
Which of the following are consequences of ocean acidification? Select all that apply.
1. Corals and coral reefs are not able to form their hard skeletons 2. Clams, mussels, lobsters, and shrimp are not able to form strong enough shells.
Acid
1. HCl -> H+ + Cl- 2. H2CO3 -> H+ + HCO3-
ten times as much
A glass of grapefruit juice, at pH 3, contains _____ H+ as a glass of tomato juice, at pH 4.
False
A hydrogen atom of one water molecular binds via a hydrogen bond to a hydrogen atom of another water molecule
Which of the following can be attributed to water's high specific heat?
A lake heats up more slowly than the air around it.
High Boiling Point
A large amount of heat energy is needed to break all hydrogen bonds between the molecules to reach the gaseous phase
hydrophobic
A molecule that has all nonpolar covalent bonds would be _____.
Which of the following helps most to explain why water has a high specific heat?
A water molecule can make 4 hydrogen bonds
A buffer consists of undissociated acid (HA) and the ion made by dissociating the acid (A-). How does this system buffer a solution against decreases in pH?
A- reacts with H+ to become HA.
Gives off excess Hydrogen Ions when dissolved in water
Acid
Substance that increases hydrogen ion concentration of a solution
Acid
compound that forms hydrogen ions (H+) in solution; ph lower than 7
Acid
Many threats to water quality have been posed ny human activities. The burning of fossil fuels releases huge amounts of CO2, sulfer and nitrous oxides which then chemically reacts with water in the are and alters the delicate balance of conditions for life on Earth- due to affecting water pH and temperature. Electric power plants that burn coal produce more oxides and wind carry the pollutants away giving acid raid the chance to fall more km away from industrial sites.
Acid precipitation is increasing. Explain its sources.
Burning fossil fuels release bad gas into air. The gas compounds react with water and the water becomes more acidic. (ex. CO2) This forms carbonic acid which lowers the pH --> ocean acidification. This results in seawater acidifying. -Extra H+ ions combine with carbonate ions to form bicarbonate ions = reduce carbonate ion concentration (required for calcification by marine life) = disappearance of coral reefs.
Acidification: Threat to Water Quality
Substance that increases the [H+] of a solution -Donate additional H+ to the solution. ex) Add HCL to water --> H+ dissociate from Cl-
Acids & how does it affect the aqueous solution??
The oxygen region of each molecule has a partial negative charge (-), and each hydrogen has a partial positive charge (+).
Add + and - signs to indicate the charged regions of each molecule. Indicate the hydrogen bonds.
lower the hydrogen ion concentration and increase the pH
Adding a base tends to _____ of a solution.
increase the hydrogen ion concentration and lower the pH
Adding acid tends to _____ of a solution.
An attraction between molecules of different substances
Adhesion
Attraction between molecules of the different substance helps counter the downward pull of gravity
Adhesion
Clinging of one substance to another Helps counter the pull of gravity
Adhesion
Clinging of one substance to another. Ex. Water in a plant cell or the lizard walking on water
Adhesion
Transpiration is due to Cohesion and _______________
Adhesion
When water molecules stick to other materials due to its polar nature
Adhesion
When water molecules stick to other molecules
Adhesion
-NH2/a nitrogen bonded to 2 hydrogens and the carbon skeleton. Acts as a base by picking up an H+ from a solution. example=amines-building blocks of proteins.
Amino Group
compound with an amino group on one end and a carboxyl group on the other end, with a specific R group; building blocks of protein; like just 26 letters in the alphabet forming countless words, just 20 of these can form thousands of different proteins by different combinations and sequences.
Amino acid
Which answer helps to explain why all living cells need pH buffers?
Amino acid side chains have many carboxyl and amino groups
a compound that donates hydrogen ions to a solution
An acid is _____.
A free radical
An atom with one unpaired electron in its outer shell and can cause conseriable cellular damage
synthetic variants of the male testosterone
Anabolic Steroids
The sum total of all processes in an organism which use energy and simple chemical building blocks to produce large chemicals and structures necessary for life.
Anabolism
Substance that reduces hydrogen ion concentration of a solution with higher concentration of OH- than H+ solution
Base
a substance that reduces the hydrogen ion concentration of a solution
Base
Proton acceptors
Bases
Reduces the [H+] ions of a solution. -By accepting hydrogen ions -Indirectly by dissociating to combine with H+ ions and form water
Bases & how does it affect the aqueous solution??
ice floats
Because molecules of water are farther apart in ice than in liquid water, _____.
10^2 = 100
Because the pH scale is logarithmic, each numerical change represents a 10X change in ion concentration. a. How many times more acidic is a pH of 3 compared to a pH of 5?
10^4 = 10,000
Because the pH scale is logarithmic, each numerical change represents a 10X change in ion concentration. b. How many times more basic is a pH of 12 compared to a pH of 8?
Why is water having high thermal capacity important for life?
Bodies of water change temperature very slowly, which is important for organisms so they can adjust to seasonal changes
Water has a high ____________ point
Boiling
False
Bonds between water molecules are stronger than the bonds between the atoms within a water molecule
A solution that minimizes changes in pH when extraneous acids or bases are added to the solution; most are acid-base pairs
Buffer
a substance that minimizes changes in the concentrations of H+ and OH- in a solution
Buffer
Allows biological fluids to maintain constant pH despite the addition of acids/bases. It minimizes changes in concentration. -Accepts hydrogen ions from solutions when in excess and donates when lacking. -Contain weak acids and corresponding bases & combine with H+
Buffers
Maintain pH in an acidic and basic environments
Buffers
pull from each one making it neutral
Buffers
Amount of energy needed to raise the temperature of 1 gram of water 1 degree C
Calorie
Amount of heat energy required to raise temperature of 1g of water by 1 degree Celsius. Also amount of heat energy that 1g of water cools by 1 degree Celsius
Calorie
Amount of heat it takes to raise the temperature of 1 gram of water by 1 degree C or the amount released to cool 1 bra of H20 by 1 degree C. Kilocalorie (1000 cal)
Calorie
amount of heat it takes to move 1 gram of substance 1 degree Celsius higher
Calorie
the amount of heat it takes to raise the temperature of 1 g of water by 1 degree Celsius
Calorie
C6H12O6 C6 = (6 x 12) = 72 H12 = (12 x 1) = 12 O6 = (6 x 16) = 96 = 180 g = 1 mole 0.5-molar glucose = 90 g. Add this mass of the compound to water bring it to volume of 1 liter. This makes 1 liter of 0.5 M solution.
Can you prepare 1 liter of a 0.5-molar glucose solution? Show your work here.
The ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity
Capillary Action
______________________ describes water's ability to use cohesion and adhesion to pull water up against gravity
Capillary Action
the attraction of the surface of a liquid to the surface of a solid, which causes the liquid to rise or fall
Capillary action
Member of the class of biological molecules consisting of single-monomer sugars (monosaccharides), two-monomer sugars (disaccharides), and polymers (polysaccharides).
Carbohydrate
a class of molecules ranging from the small sugar molecules dissolved in soft drinks to large polysaccharides like starches
Carbohydrate
-serve as a cell's fuel and building material -the class of molecules that range from small sugar molecules (such as those dissolved in soft drinks) to large polysaccharides (such as starch) -composed of C, H, and O -hydrophilic -has two types : monosaccharides and polysaccharides -have molecular formulas that are multiples of CH2O (e.g. C60H100O50)
Carbohydrates
The chain of carbon molecules that forms the structural backbone of an organic molecule.
Carbon Skeleton
the chain of carbon molecules in a molecule
Carbon Skeleton
Why is vegetable oil hydrophobic?
Carbon and hydrogen share electrons almost equally
Example of buffer
Carbonic acid
>C=O/a carbon atom is linked by a double bond to an oxygen atom. example-sugars
Carbonyl Group
\ C=O /. a C atom linked by a double bond to an O.
Carbonyl Group
-COOH a C double bonded to a O and bonded to a hydroxyl group.
Carboxyl Group
-COOH/a carbon double bonded to an oxygen atom and also bonded to a hydroxyl group. example=acetic acid
Carboxyl Group
dissolved substances can be easily transported within a cell or between cells in multicellular organisms a variety of nutrient molecules is readily available as dissolved solutes the temperature of living things tends to change relatively slowly waste products produced by cell metabolism can be easily removed All of the listed responses are correct.
Cells are surrounded by water, and cells themselves consist of about 70 to 95% water. As a result, _____.
A structural polysaccharide, consisting of amino sugar monomers, found in many fungal cell walls and in the exoskeletons of all arthropods.
Chitin
structural polysaccharide used by insects to build exoskeleton
Chitin
component in cell membranes
Cholesterol
Attraction between molecules of the same substance
Cohesion
Linking of same molecules and holding together. Hydrogen bonds hold water together & keeps them close. Molecules still very transient.
Cohesion
Linking together of like molecules with hydrogen bonds. Ex. Water drops on penny
Cohesion
Transpiration is due to ________________ and Adhesion
Cohesion
When water molecules stick to each other
Cohesion
When water molecules stick to other water molecules
Cohesion
attraction between molecules of the same substance, transport of water and dissolved nutrients against gravity in plants
Cohesion
hydrogen molecules hold water molecules together (water and water)
Cohesion
the hydrogen bonds hold the substance together
Cohesion
1. Large body of water can absorb and store a huge amount of heat and warm up slightly to a few degrees. 2. Gradually cooling water can warm/moderate air temp. 3. Stabilize ocean/ earth temperatures (which permits life) 4. Organisms = mostly water = resist changes in own temperature
Contribution of Water's High Specific Heat to Life on Earth
-Transport of water & dissolved nutrients against gravity in plants Water evaporates from leaf → H bonds cause water molecules leaving the veins to tug on molecules farther down. Upward pull transmitted through the water conducting cells all the way to the roots.
Contributions of Cohesion
1. Stability of temperature in lakes and ponds 2. Prevent overheating (sweat evaporated) That is why high humidity = uncomfortable bc high concentration of water vapor in the air.
Contributions of Evaporative Cooling of Water
What type of bond is between the oxygen and hydrogen in water?
Covalent Bond
A COVALENT BOND forms when electrons are shared between atoms. An IONIC BOND is formed when one or more electrons are transferred from one atom to another.
Covalent bond vs Ionic bond
A double-stranded helical nucleic acid molecule consisting of nucleotide monomers with deoxyribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and thymine (T). Capable of replicating, is an organism's genetic material. See also gene.
DNA
deoxyribonucleic acid, a self-replicating material present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.
DNA
genetic inheritance polymer
DNA
Evaporation is the transformation of a liquid to a gas. The evaporation of water from leaves of a plant helps keep the tissues in the leaves from becoming too warm in the sunlight. The evaporation of sweat from human skin dissipates body heat and helps prevent overheating on a hot day or as a result of excess heat created by strenuous activity.
Define evaporation. Explain at least three effects of this property on living organisms.
Molarity is the number of moles of solute per liter of solution—is the unit of concentration most often used by biologists for aqueous solutions.
Define molarity.
A molecule with an uneven distribution of charges in different regions of the molecule
Define polar molecule
A chemical reaction in which two molecules become covalently bonded to each other with the removal of a water molecule.
Dehydration Reaction
a reaction that removes a molecule of water
Dehydration Reaction
H2O+C12H22O11
Dehydration synthesis reaction C6H12O6+C6H12O6 --->
A process in which a protein unravels, losing its specific structure and hence function; can be caused by changes in pH or salt concentration or by high temperature. Also refers to the separation of the two strands of the DNA double helix, caused by similar factors.
Denaturation
polypeptides unravel, losing their specific shape, and changes its function
Denaturation
Strong acids completely ionize in a solution, but weak acides do not completely ionize in a solution
Difference between a strong acid and a weak acid
A sugar molecule consisting of two monosaccharides linked by a dehydration reaction.
Disaccharide
two monosaccharides linked together
Disaccharide
Lowers pH. Reduces carbonate concentration. Required for calcification the production of calcium carbonate which helps build reefs.
Discuss how CO2 emissions affect marine life and ecosystems
About half the CO2 emitted stays in atmosphere, acting like a reflective blanket over the planet that traps heat by preventing it from escaping into outer space. While photosynthesizing organisms absorb some of the gas, approximately 30% is taken up by the oceans, and excessive CO2 uptake might damage the fragile marine ecosystem. CO2 dissolves in sea water creating carbonic acid which then seperates to bicarbonate and carbonate. Sea water acidifies due to the extra protons which lowers the pH of the ocean. Ocean acidification decreases the carbonate concentration, which is required for calcification by many marine organisms. Additionally, CO2 emissions create acid precipitation that damages life in streams and lakes and adversely affects life on land by altering soil chemistry.
Discuss how CO2 emissions affect marine life and ecosystems.
Cohesion is the phenomenon of the collective hydrogen bonds holding water together. Adhesion, however, is the clinging of one substance to another.
Distinguish between cohesion and adhesion.
Any substance that has an affinity for water is said to be hydrophilic, whereas substances that are nonionic and nonpolar and cannot form hydrogen bonds and therefore seem to repel water and are called hydrophobic. An example of a hydrophilic substance is cotton, whereas an example of a hydrophobic substance is vegetable oil.
Distinguish between hydrophobic and hydrophilic substances. Give an example of each.
The form of native DNA, referring to its two adjacent polynucleotide strands wound into a spiral shape.
Double helix
Lubricant
Due to hydrogen bonding, water tends to adhere to surfaces, such as the lining of the digestive tract.
A macromolecule, usually a protein, that serves as a biological catalyst, changing the rate of chemical reaction without being consumed by the reaction.
Enzyme
Process by which a liquid changes to gas
Evaporation
Example of evaporative cooling
Evaporation of sweat from human skin prevents overheating on a hot day
A buffer is a substance that minimizes changes in the concentration of H+ and OH- in a solution. It does so by accepting hydrogen ions from the solution when they are in excess and donating hydrogen ions to the solution when they have been depleted. Most buffer solutions contain a weak acid and its corresponding base, which combine reversibly with hydrogen ions.
Even a slight change in pH can be harmful! How do buffers moderate pH change?
water droplets Transport of water and dissolved nutrients against gravity in plants
Example of cohesion
Carbonic acid (H2CO3) is formed when CO2 reacts with water in the blood plasma. Carbonic acid dissociates to yield a bicarbonate ion (HCO3 -) and a hydrogen ion (H+). The chemical equilibrium between carbonic acid and bicarbonate acts as a pH regulator, the reaction shifting from left or right as other processes in the solution add or remove hydrogen ions.
Exercise will result in the production of CO2, which will acidify the blood. Explain the buffering system that minimizes blood pH changes.
Oxygen has six electrons in its outer shell. When two oxygen atoms bind together, two pairs of electrons share, giving the oxygen atom eight electrons to become stablized according to the octet rule.
Explain how an oxygen molecule obeys the octet rule.
Cohesion helps hold together the column of H20 with in the cells. Also, as water evaporates from the leaves, Hydrogen bonds cause H20 molecules leaving to tug on molecules further down. Upward pull is transmitted through the cell. With adhesion, the water clings to the plant cell wall, which counters gravity.
Explain how cohesion and adhesion relate to water in trees
Heat is absorbed and released when hydrogen bonds form; therefore, a calorie of heat causes a relatively small change in the temperature of water because much of the heat is used to disrupt hydrogen bonds before water molecules can begin moving faster. Additionally, when the temperature of water drops slightly, many additional hydrogen bonds form, releasing a considerable amount of energy in the form of heat
Explain how hydrogen bonding contributes to water's high specific heat.
Positive hydrogen of one molecule attracted to negative oxygen of nearby molecule. Water can form four bonds.
Explain hydrogen bonding in terms of water. How many hydrogen bonds can a single water molecule form?
Hydrogen bonding occurs when the slightly positive hydrogen of one molecule is attracted to the slightly negative oxygen of a nearby molecule, holding them together. Hydrogen bonds are fragile and at any given moment a substantial percentage of all the water molecules are hydrogen-bonded to their neighbors. Each water molecule can form 4 hydrogen bonds.
Explain hydrogen bonding. How many hydrogen bonds can a single water molecule form?
The H+ concentration of a pH 12 is 104 times greater than that of a pH of 8.
Explain the difference between a pH of 8 and a pH of 12 in terms of H+ concentration.
An energy shell is a region outside the nucleus of an atom occupied by electrons of a given energy level. More than one oribital can be found within an energy shell. An orbital may be spherical or dumbbell shaped and contains up to two electrons.
Explain the difference between an energy shell and an orbital.
The fact that water is such a versatile solvent can be traced back to the polarity of the water molecule. Water can dissolve ionic compounds, many compounds made up of nonionic polar molecules, as well as molecules such as proteins if they have polar and ionic regions on their surface.
Explain why water is such a fine solvent
large lipid made from two kinds of smaller molecules: glycerol and fatty acids
Fat
Solid form of water is less dense than liquid form of water. So, it floats.
Floating Ice on Water
1. Cohesive behavior 2. Ability to moderate temperature 3. Expansion upon freezing 4. Versatility as a solvent
Four emergent properties of water that contribute to Earth's sustainability for life
A specific configuration of atoms commonly attached to the carbon skeletons of organic molecules and involved in chemical reactions.
Functional Groups
a group of atoms responsible for the characteristic reactions of a particular compound
Functional Groups
A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, in some viruses). Most of the genes of a eukaryote are located in its chromosomal DNA; a few are carried by the DNA of mitochondria and chloroplasts.
Gene
amino acid sequence program of inheritance
Gene
Chemical Formula for Water
H20
A large amount of heat energy is needed to break all hydrogen bonds between the molecules to reach the gaseous phase
High Boiling Point
What is temperature stability
High specific heat of water
process by which organisms maintain a relatively stable internal environment
Homeostasis
Minimizes changes in concentration of H+ OH- in a solution. Accepts hydrogen ions from the solution when they are in excess and bonding hydrogen ions to solution
How can buffers moderate pH changes?
Adding certain solutes (acids and bases) Acids Bases
How can the balance of water's pH be disrupted? (imbalance in H+ and OH- concentrations)
Water may cool air at night and warm during the day. High specific heat stabilizes ocean temperatures. This is important to life because organisms made of water are able to resist changes in their own temperature. Keeps life in balance.
How does Water's high specific heat contribute tot he moderation of temperature. How is this property important to life?
can absorb huge amount of heat at night while gradual cooling can warm the air
How does high specific heat of water affect temperature in large bodies of water?
heat breaks the hydrogen bonds before raising temperatures of water, cooling FORMS hydrogen bonds
How does hydrogen bonding contribute to water's high specific heat?
Ice absorbs enough heat for temperature to go above 0 degrees C and the H Bonds are disrupted, causing the lattice to collapse.
How does melting work at a molecular level?
if ice sank, ponds/oceans/lakes would freeze solid, killing the life (during the summer only top would thaw) instead the floating ice insulates liquid water from below preventing it from freezing and killing animals
How does the density of water contribute to aquatic life?
Because it is polar, water's oppositely charged ends are attracted to positively and negatively charged ions and molecules. Water molecules form a hydration shell around oppositely charged particles.
How does the polarity of water contribute to its ability to dissolve so many substances?
@ 4 C, H20 behaves like other liquids @4-0, H20 begins to freeze because the molecules moving are moving to slow in order to break the H Bonds @0, Molecules lock into a crystal lattice. The H Bonds keep molecules at arms length, which causes it to be 10% less dense than liquid h20.
How does water behave above 4 degrees C? From 4 to 0 degrees C? At 0 degrees C?
Day: Absorb and store huge amount of heat from the sun Night: Gradually cooling water can warm the air Stabilize ocean temperatures, creating favorable environment for marine life
How is specific heat helping us?
Very transiently. The H Bonds constantly change.
How well are molecules connected by hydrogen bonds in liquid form of water?
the sphere of water molecules around a dissolved ion
Hydration shell
the sphere of water molecules around each dissolved ion
Hydration shell
An organic compound composed only of the elements carbon and hydrogen.
Hydrocarbons
compounds composed of only hydrogen and carbon
Hydrocarbons
organic molecules consisting of only carbon and hydrogen
Hydrocarbons
H+
Hydrogen
A relatively weak bond between the partial negative side of one molecule and partial positive side of another molecule
Hydrogen Bond
What type of bond is between two water molecules?
Hydrogen Bond
Slight (+) H of one molecule attracts to slight (-) of another molecule nearby = H Bond. - Always breaking and reforming!
Hydrogen Bond with Water Molecules
Adhesion is due to _______________
Hydrogen Bonding
Transpiration is due to Cohesion and Adhesion, which are due to _______________________
Hydrogen Bonding
Cohesion is due to _______________
Hydrogen bonding
Covalent bonds involve sharing of electrons between atoms but hydrogen bonds are the result of weak attractions between a hydrogen atom of a polar molecule and an electronegative atom of another polar molecule.
Hydrogen bonds differ from covalent bonds in that
Why is ice more dense than water?
Hydrogen bonds in ice are more ordered
(H+) a single proton with a charge of 1+
Hydrogen ion
A chemical reaction that breaks bonds between two molecules by the addition of water; process by polymers are broken down and an essential part of digestion.
Hydrolysis
a molecule of waterreaction with the breaking of bonds with water
Hydrolysis
(H₃O+)
Hydronium ion
"Water-loving"; pertaining to polar or charged molecules (or parts of molecules) that are soluble in water.
Hydrophilic
(water loving) any substance that is attracted to water
Hydrophilic
Substance that loves water Don't necessarily have to dissolve ex) Cells & Cotton (made up of cellulose)
Hydrophilic
any substance that has an affinity of water is said to be hydrophilic
Hydrophilic
water loving (soluble in water)
Hydrophilic
have charges and partial charges to which water molecules can adhere
Hydrophilic substances, but not hydrophobic substances, _____.
h2o loving (cotton)
Hydrophillic
"Water-fearing"; pertaining to nonpolar molecules (or parts of molecules) that do not dissolve in water.
Hydrophobic
(water fearing) any substance that repels to water
Hydrophobic
No affinity for water (vegetable oil) water fearing...
Hydrophobic
Nonionic/nonpolar (cannot form hydrogen bonds)
Hydrophobic
Substances that don't love H20. They are not ionic and are non polar. So they can't form Hydrogen Bonds Ex) Oil. Its hydrophobic behavior is between Carbon and Hydrogen (non polar covalent bonds) which share electrons equally. Ex) Cell membranes
Hydrophobic
water fearing
Hydrophobic
repelled by
Hydrophobic molecules are _____ water.
(OH-) has a charge of 1-
Hydroxide ion
OH-
Hydroxyl
(-OH) consists of a H atom bonded to an O atom which in turn is bonded to a C.
Hydroxyl Group
-OH/consists of a hydrogen atom bonded to an oxygen atom, which in turn is bonded to the carbon skeleton. example: alcohols
Hydroxyl Group
If ice sank, eventually ponds, lakes, and oceans would freeze solid and only a few inches at the top would thaw during the summer. Because ice floats, the upper frozen layer insulates the liquid water below, keeping it from freezing and allowing life to exist beneath the surface. Additionally, the frozen layer provides a solid habitat for some animals, such as polar bears and seals.
Ice floats! So what? Consider what would happen if ponds and other bodies of water accumulated ice at the bottom. Describe why this property of water is important.
False
Ice is denser than liquid water at all temperatures
How can ice float in liquid water?
Ice is less dense than water
Advantage of the Properties of Water
Ice serves as an insulating blanket for aquatic ecosystems protecting them from the cold air at surface
The effects would be drastically worse because the loss of the polar nature of water would greatly reduce its specific heat and its ability to moderate temperature.
If water were not a polar molecule, how would the effects of global warming differ from what are currently observed or predicted to occur in the future?
7. Slight changes can be harmful because processes are very sensitive Blood has a pH of 7.4 and a person cannot survive if it goes to 7 or 7.8.
Internal pH of living cells
Creation of hydration shell! - The Ions and H20 molecules attract to each other because of their opposite charges. H2O surround the individual Na and Cl ions, separating and shielding them from one another. Working from the surface to inward, water eventually dissolves all ions. Result= homogeneous mixture.
Ionic Compounds Dissolving (ex. NaCl)
Same atoms but different arrangement.
Isomers
element with different # of neutrons
Isomers
Why is water being a good evaporative coolant important for life?
It allows organisms to maintain body temperature in a warm environment
Why does ice float on water?
It is less dense than water
What does high surface tension do to the surface of a liquid?
It makes it slightly more difficult to break through than the interior
How does water dissolve substances?
It surrounds charged particles and pulls them into solution
How does the way a buffer stabilizes pH during addition of acid differ from the way the same buffer stabilizes pH during addition of base?
It's the same reaction running backward or forward
Why is water called the universal solvent?
Its properties allow it to dissolve almost anything
SI unit of energy
Joule
the quantity of heat required to raise the temperature of 1 kilogram of water by 1 degree Celsius
Kilocalorie (kcal)
Energy of motion Atoms and molecules --> Always in motion
Kinetic Energy
Anything that moves
Kinetic energy
energy of motion
Kinetic energy
What is this an image of?
Lattice Arrangement of Frozen Water (Ice)
What is solute in lemonade?
Lemon
An organic compound consisting mainly of carbon and hydrogen atoms linked by nonpolar convalent bonds, making the compound mostly hydrophobic. Lipids include fats, phospholipids, and steroids and are insoluble in water.
Lipid
Carbon, hydrogen, nitrogen, oxygen
Living organisms are composed mainly of which atoms?
A large molecule formed by the joining of smaller molecules, usually by a dehydration reaction: a protein, carbohydrate, or nucleic acid.
Macromolecules
carbohydrates, proteins, and nucleic acids
Macromolecules
Buffers
Maintain pH in an acidic and basic environments
nonpolar
Methyl
-CH3 a C bonded to three H
Methyl Group
-CH3/consists of a carbon bonded to 3 hydrogens.
Methyl Group
By absorbing or releasing heat from/to the air. Can absorb/release large amount of heat with only slight change in its own temperature.
Moderation of Temperature by Water Why is water an effective heat bank?
Number of moles of solute per liter of solution. Unit of concentration used for aqueous solutions
Molarity
the number of moles of solute per liter of solution
Molarity
sum of the mass of all the atoms in a molecule
Molecular Mass
The sum of the masses of all the atoms in a molecule
Molecular mass
Why does water freeze?
Molecules move too slowly to break hydrogen binds
The subunit that serves as the building block of a polymer.
Monomers
one of the repeating parts of a polymer
Monomers
The simplest carbohydrate; a simple sugar with a molecular formula that is generally some multiple of CH2O. Monosaccharides are the building blocks of disaccharides and polysaccharides.
Monosaccharide
a carbohydrate monomer
Monosaccharides
glucose, fructose, galactose
Monosaccharides
hydrophobic
Nonpolar molecules that cluster away from water molecules are called _____ molecules.
As a result of hydrogen bonding, water expands as it solidifies. At 4°C water acts like other liquids, expanding as it warms and contracting as it cools. However, below 4°C water begins to freeze as more and more hydrogen molecules are moving to slowly to break the hydrogen bonds. Hydrogen bonds keep the molecules far enough apart to make ice about 10% less dense than water at 4°C; it is this lower density of ice that allows it to float.
Now, explain why ice floats. Why is 4°C the critical temperature?
Steps to prepare a solution: a. Write the molecular formula. C12H22O11 b. Use your periodic table to calculate the mass of each element. Multiply by the number of atoms of the element. (For example, O has a mass of 16. Therefore, one mole of O has a mass of 16 x 11 = 176 g/mole.) C12 = (12 x 12) = 144 H22= (22 x 1) = 22 O11= (11 x 16) = 176 c. Add the masses of each element in the molecule. 144 + 22 + 176 = 342 g d. Add this mass of the compound to water to bring it to a volume of 1 liter. This makes 1 liter of a 1 M (1- molar) solution.
Now, let's do a little work that will enable you to prepare solutions. Read the section on solute concentrations carefully, and show the calculations here for preparing a 1-molar solution of sucrose. Steps to help you do this follow. The first step is done for you. Fill in the rest.
A polymer consisting of many nucleotide monomers; serves as a blueprint for proteins and, through the actions of proteins, for all cellular structures and activities. The two types of nucleic acids are DNA and RNA.
Nucleic Acid
gene polymers
Nucleic Acids
An organic monomer consisting of a five-carbon sugar covalently bonded to a nitrogenous base and a phosphate group. Nucleotides are the building blocks of nucleic acids.
Nucleotides
Protons and neutrons
Nucleus of the atom
hydroxide ion; base
OH-
How are oyster larvae affected by ocean acidification?
Oyster larvae cannot grow shells in acidified ocean waters
What is the charge of the orange circle in this image?
Partial Negative
What is the charge of the red circle in this image?
Partial Negative
δ-
Partial Negative
Water has a _______________________ charge near the hydrogen atom
Partial Positive
What is the charge of the green circle in this image?
Partial Positive
What is the charge of the yellow circle in this image?
Partial Positive
δ+
Partial Positive
covalent linkage between peptides to form a poly peptide
Peptide Bond
A lipid made up of glycerol joined to two fatty acids and a phosphate group, giving the molecule a nonpolar hydrophobic tail and a polar hydrophilic head. Phospholipids form bilayers that function as biological membranes.
Phospholipid
What type of molecule is water (polar or nonpolar)
Polar
atoms within the bond do not have the same pull on the shared electron, and as a result the electron spends more time around one atom relative to the other atom within the bond.
Polar covalent bond is created when
Oxygen is more electronegative than hydrogen, so the electrons of the covalent bonds spend more time closer to oxygen
Polar covalent bonds
Oxygen more electronegative than hydrogen
Polar covalent bonds
the electrons of the covalent bonds are closer to oxygen than to hydrogen
Polar covalent bonds
hydrogen bonding
Polar covalent bonds in water molecules result in....
overall charge is unevenly distributed
Polar molecule
the overall charge is unevenly distributed
Polar molecule
the water overall charge is unevenly distributed
Polar molecule
Why doesn't oil mix with water?
Polar molecules attract one another.
A long molecule consisting of many similar or identical monomers linked together.
Polymer
A large molecule consisting of many identical or similar monomers linked together by covalent bonds.
Polymers
a large molecule consisting of many identical chains linked together
Polymers
A polymer (chain) of amino acids linked by peptide bonds.
Polypeptide
A polymer (chain) of many amino acids linked together by peptide bonds.
Polypeptide
a polymer made of peptides
Polypeptide
large macromolecules formed from monosaccharides; Carbohydrates that are made up of more than two monosaccharides
Polysaccharides
Hydrogen has partially what charge?
Positive
linear sequence of amino acids
Protean Primary Structure
An organic compound that is made of one or more chains of amino acids and that is a principal component of all cells
Protein
a polymer made of 20 amino acids/the most elaborate, diverse structurally
Protein
association of multiple peptides
Protein Quaternary Structure
alpha helix and beta pleated sheet formed by hydrogen bonds between atoms of the polypeptide backbone
Protein Secondary Structure
three-dimensional shape formed by interactions between R groups
Protein Tertiary Structure
formation of carbonic acid from carbon dioxide and water
Pure water has a pH of 7. Why does uncontaminated rainwater have a pH of 5.6?
Groups giving different amino acids different properties. Range from a single hydrogen atom to complex arrangements of carbon chains and ring structures.
R groups
groups give different amino acids different properties. R groups range from a single hydrogen atom to complex arrangements of carbon chains and ring structures. Thus organisms have a diverse pool of building blocks from which they can make proteins with many different properties.
R groups
A single-stranded nucleic acid that passes along genetic messages; its job is in assembling the polypeptides according to the instructions of DNA.
RNA
A type of nucleic acid consisting of nucleotide monomers with a ribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and uracil (U); usually single-stranded; functions in protein synthesis and as the genome of some viruses.
RNA
translates sequence of programming into proteins
RNA
adenine, cytosine, guanine and uracil
RNA has...
hydrolytic
Reactions that involve water in the breaking apart of other molecules are known as ____ reactions
Hydrogen Bonding! Heat absorbed = break H bonds Heat released = form H bonds Much of the eat is used up to disrupt bonds before water molecules can begin moving faster
Reason for High Specific Heat
Pertaining to fats and fatty acids whose hydrocarbon chains contain the maximum number of hydrogens and therefore have no double covalent bonds. Saturated fats and fatty acids solidify at room temperature.
Saturated Fatty Acid
Increased atmospheric CO2 concentrations might have what effect on seawater?
Seawater will become more acidic, and carbonate concentrations will decrease.
The second level of protein structure; the regular local patterns of coils or folds of a polypeptide chain.
Secondary structure
Example of a Base
Sodium Hydroxide
NaOH
Sodium Hydroxide
What states does water exist in?
Solid, Liquid, and Gas
molecules are hydrophilic
Soluble
Substance that is dissolved
Solute
substance that is dissolved in a solvent
Solute
Hydrophilic and polar molecules
Solutes that can easily dissolve in water are said to be
A homogeneous mixture of two or more substances
Solution
A liquid that is completely homogenous mixture of 2 or more substances
Solution
a liquid that is a completely homogeneous mixture of two or more substances
Solution
mixture of 2 ore more substances (ex: solute dissolved in a solvent)
Solution
How well substance resists temperature changes. Amount of heat that must be absorbed/lost for 1 gram to change its temperature by 1 degree C.
Specific Heat
The amount of energy needed to raise 1 gram of a water 1 degree Celsius
Specific Heat
The amount of energy required to raise the temperature of 1 gram of a substance by 1 degree C
Specific heat
amount of heat needed to be absorbed /lost to change the temperature by 1 degree Celsius
Specific heat
the amount of heat that must be absorbed or lost for 1 g of that substance to change its temperature by 1 degree Celsius
Specific heat
Covalent bonds
Strong chemical bonds due to the sharing of electrons. Bonds between hydrogen and oxygen atoms within a molecule.
glucose + fructose; table sugar
Sucrose
stir 342 g of sucrose in water to dissolve the sugar, and then add enough water to bring the total volume of the solution up to 0.5 L
Sucrose has a molecular mass of 342 daltons. To make a 2-molar (2 M) solution of sucrose, _____.
With a high specific heat, a large body of water can absorb and store a huge amount of heat from the sun in the daytime and during summer while warming up only a few degrees. As this water generally cools during the night and during winter, it warms the air, contributing to milder climates in coastal regions.
Summarize how water's high specific heat contributes to the moderation of temperature. How is this property important to life?
A measure of how difficult it is to break/stretch a surface
Surface Tension
Creates the skin-like surface and droplets or beading formed due to the polar nature of water
Surface Tension
How easy/hard it is to break/stretch the surface of liquids. -Water has high surface tension (is really strong) because at the interface of air and water, there's an arrangement of molecules hydrogen bonded to one another.
Surface Tension
a measure of how difficult it is to stretch or break the surface of a liquid
Surface tension
heat of vaporization
Sweating has a cooling effect because of water's high _____.
Which has higher thermal energy, swimming pool or coffee pot and why?
Swimming pool, greater volume
intensity of heat due to average kinetic energy
Temperature
this represents average K.E. of molecules in a body of matter
Temperature
False
Ten to twenty percent of the body weight in humans is from water.
Capillary Action
The ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity
electronegativity
The ability of an atom to attrom electrons in a bond with another atom is termed
both caused by water's partial charges
The ability of water molecules to form hydrogen bonds with other water molecules and water's ability to dissolve substances that have charges or partial charges are _____.
increases the hydrogen ion concentration in the oceans but decreases the carbonate ion concentration and threatens the livability of the oceans for calcifying organisms
The absorption of human-generated CO2 by the oceans _____.
Hydrolysis
The addition of water can break apart molecules into two smaller molecules.
the specific heat of that substance
The amount of heat required to change the temperature of 1 g of any substance by one °C is defined as _____.
the heat of vaporization of that substance
The amount of heat required to convert 1 g of any substance from the liquid to the gaseous state is defined as _____.
..
The pH Scale
the unequal sharing of electrons between the hydrogen and the oxygen atoms of a water molecule
The partial charges on a water molecule occur because of _____.
cohesion
The phenomenon responsible for maintaining the upward movement of water through a vessel is _____.
True
The polar covalent bonds between hydrogen and oxygen atoms within a water molecule create slight positively and negatively charged ends to the molecule.
Things dissolving in water is possible due to...
The polarity of water
keeps water moving through the vessels in a tree trunk acts to moderate temperature provides the surface tension that allows leaves to float on water is called cohesion All of the listed responses are correct.
The tendency of water molecules to stay close to each other as a result of hydrogen bonding _____.
Kinetic energy due to the random movement of atoms. **NOT THE SAME AS TEMPERATURE , but related -Total TE depends on volume
Thermal Energy
kinetic energy of motion with random movement of atoms or molecules is...
Thermal energy
the kinetic energy associated with the random movement of atoms or molecules
Thermal energy
What happens when two objects of different temperature are brought together?
Thermal energy pass from warmer to cooler object
Which statement is true of pH buffers?
They consist of weak acids and weak bases
Water, which is neutral with a pH of 7, has an equal number of H+ and OH- ions
To go a step further, the product of H+ and OH- concentrations is constant at 10-14. [H+] [OH-] = 10-14
Gravity
Trees take up water from their roots. Water must travel up against ____ up to all of the branches and leaves.
Water absorbs heat from the air and releases the stored heat to cooler air
True or False:
The specific heat of a substance is defined as the amount of heat that must be absorbed or lost for 1 g of that substance to change its temperature by 1°C. Water's specific heat is unusually high at 1 cal/g•°C, whereas alcohol's specific heat is is 0.6 cal/g•°C.
Water has high specific heat. What does this mean? How does water's specific heat compare to alcohol's specific heat?
Transpiration in Water
Water is carried from the roots to the stomata. There it changes to vapor and is released to the atmosphere
Dehydration reaction
Water is formed when two molecules come together to form a large molecule.
Ice floats
Water is less dense at 0°C compared to 4°C.
Compare specific heat of iron and water
Water is ten times greater
True
Water is the universal solvent, transporting dissolved substance in bodily fluids
a higher boiling point
Water molecules have _____ than molecules of similar size, such as ammonia and methane, reflecting its capacity to absorb large amounts of heat.
True
Water plays a major role in our bodies' chemical reactions
False
Water plays a much more important role in plants than in animals, due to the role of water in photosynthesis
Turgid pressure in plants
Water provides structural support due to its inability to be compressed.
1 cal/g x C degrees Changes temperature less than other liquids/objects absorb/lose heat. Resists change in its temperature. It takes a lot of absorbing/losing for each degree of change. (The same amount of heat will raise the temperature of 1 gram of iron much faster than it will raise the temperature of 1 gram of water)
Water's High Specific Heat
Polarity of H20
Water's Versatility as Solvent
To evaporate 1 gram of water at 25 degrees C, 580 cal of heat is needed (double the amount for alcohol). **Property resulting from the strength of its hydrogen bonds (which must be broken before molecules can exit the liquid in the form of vapor)
Water's high heat vaporization
1 cal/g/C
Water's specific heat
Leads to water's unique emergent properties that help make Earth suitable for life.
Water's structure allows it to interact with other molecules, including other water molecules!! Trace water's unique behavior to the structure and interactions of its molecules!!
Why is water having a high boiling point important for life?
We are made up of about 70% water; The oceans don't boil away at high temperatures; Humans don't boil away at high temperatures
It can absorb or release a large amount of heat with only a slight change in its own temperature
What does it mean when a substance has a high specific heat?
because of hydrogen bonding, at temperatures above 4 degree celsius , water behaves like other liquids (expanding as it warms, contracting as it cools), molecules began to freeze when molecules no longer move vigorously to break hydrogen bonds. At O degree celsius, the water is locked in crystalline lattice and keeps hydrogen bonds at "arm's length", at temperatures above 4 degrees Celsius, bonds are free to slip close
What happens to the density of water as temperature decreases?
the actual [H+] and [OH-] changes greatly.
What happens when pH changes slightly?
Maintains equillibrium
What has a pH of 7 pH is defined as the negative log of the hydrogen ion concentration [H+]. How is water assigned a pH of 7?
Since oxygen is more electronegative than hydrogen, the electrons of the covalent bonds between them are more strongly attracted to oxygen's than hydrogen's nucleus. This unequal distribution of electrons makes water a polar molecule, meaning that the two ends of the molecule have opposite charges.
What is a polar molecule? Why is water considered polar?
Carbonic acid H2CO3 <----> HCO3- + H+ See more in notes.
What is an example of a buffer that stabilizes biological pH in blood?
The heat of vaporization is the quantity of heat a liquid must absorb for 1 g of it to be converted from the liquid to the gaseous state. The heat of vaporization accounts for the severity of steam burns, burns caused by the heat energy released when steam condenses into liquid on the skin.
What is heat of vaporization? Explain at least three effects of this property on living organisms.
10-7 M
What is the concentration of each ion in pure water at 25 degrees celsius?
10-7 M (at 25°C)
What is the concentration of each ion in pure water at 25°C?
10E-14 If acid is added to the solution to increase [H+] (ex. to 10E-5], then [OH-] will decline by an equivalent factor so that when they are multiplied, it is still that constant.
What is the constant of [H+][OH-] in any aqueous solution at 25 degrees C?
Can drastically affect cells
What is the danger of disrupting the balance of H+ and OH-?
H2O
What is the molecule that supports all life?
6
What is the pH of urine?
1 calorie/1 gram/I degree Celsius
What is the specific heat of water?
1 cal/g/degree C
What is water's specific heat?
Carbon dioxide
What products of fossil fuel burning contribute to acid precipitation?
hydronium (H3O+) and hydroxide ions (OH-) (we will represent the hydronium ion as H+)
What two ions form when water dissociates?
hydronium ion hydroxide ion
What two ions form when water dissociates?
In 2008, the robotic spacecraft Phoenix found ice present just under the material on Mars's surface, and detected sufficient water vapor in the Martian atmosphere for frost to form.
What water-related evidence do scientists have that suggests life may exist on other planets?
Everything would freeze. Ice frozen on top allows life underneath to survive
What would happen to organisms if ice froze at the bottom?
Adhesion
When water molecules stick to other molecules
Cohesion
When water molecules stick to other water molecules
acidic (pH 2)
When you add HCl to a substance, it becomes more ______
basic (pH 12)
When you add NaOH to a substance, the solution becomes more _______
Between oppositely charged atoms of different molecules.
Where do the properties of H20 arise from?
condensing 5 g of steam to liquid water
Which action would involve the greatest transfer of heat?
Adhesion: water molecules attached to other water molecules to form a bead.
Which is demonstrated when you see beads of water on a waxed car hood?
The significant increase in Arctic air temperature over the past 50 years is causing sea ice to form later in the year, to melt earlier, and to cover a smaller area each year.
Which of the following accurately relates the emergent properties of water to the effects of global warming in the Arctic?
HF → H⁺ + F⁻
Which of the following dissociations is that of an acid?
It washes away some minerals that are plant nutrients, and causes some toxic minerals to accumulate.
Which of the following statements is true about acid precipitation?
The point at which the surface of the water interacts with air is an ordered molecular arrangement, causing the water to behave as though coated with an invisible film. This is attributable to water's high surface tension.
Which property explains the ability of a water strider to walk on water?
Cohesive force
While hydrogen bonds are constantly breaking and reforming a large percentage of the hydrogen bonds between water molecules exist at all times
In order to perform their function of separating the aqueous solutions outside of cells from the aqueous solutions inside of cells, cell membranes cannot be soluble in water.
Why are cell membranes composed primarily of hydrophobic molecules?
Because they are attracted to one another
Why do molecules of any liquid stay close together?
Ice is less dense than water. Less than 4 degrees Celsius water begins to freeze because more of its molecules move too slow to break hydrogen bonds
Why does ice float? Why is 4 degrees Celsius a critical temperature?
Sodas typically contain sugar, flavorings, coloring agents, and carbon dioxide dissolved in water. The best term to describe this mixture would be _____.
an aqueous solution
The open spaces in water's crystal structure make it possible for ...
aquatic life to exist at the North Pole
a solution in which water is the solvent
aqueous solution
one in which water is the solvent
aqueous solution
water is solvent
aqueous solution
hydrophobic because they have relatively nonpolar bonds
are oil molecules hydrophilic or hydrophobic?
6.02 x 10^23
avogadro's number
a substance that reduces the H+ concentration of a solution
base
decreases hydrogen concentration
bases
reduce H+ concentration
bases
more than 7
basic
water
biologists seeking life on other planets have concentrated their search on planets that might have what?
substances that minimize changes in concentrations of H+ and OH- in a solution
buffers
weak acids and bases
buffers
unit of energy
calorie
Hydrogen bonds
can form between H and N.
yes as long as they have ionic and polar regions
can large polar molecules such as proteins dissolve in water?
to polynucleotides wrap around eachother
double Helix
The tendency of an atom to pull electrons toward itself is referred to as its _____.
electronegativity
Proteins (macromolecules) that speed up chemical reactions
enzymes
Proteins that speed up chemical reactions
enzymes
proteins that act as biological catalysts
enzymes
What process exerts the pull on water molecules that is relayed from leaf to root via cohesion?
evaporation
process of liquid becoming gas
evaporation
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.
evaporative cooling
transformation of a substance from liquid to gas
evaporative cooling
temperature in organisms and bodies of water
evaporative cooling of water stabilizes what
it accepts hydrogen ions from the solution when they are in excess and donates hydrogen ions to the solution when they are depleting
even a slight change in pH can be harmful. how do buffers moderate pH change?
capillary action
example of adhesion
Carbonic acid dissociates to yield a bicarbonate ion and a hydrogen ion. the chemical equilibrium regulates pH. if H+ concentration falls, the reaction goes to the right and more carbonic acid dissociates and replenishes hydrogen ions
exercise results in the production of CO2, which will acidify the blood. Explain the buffering system that minimizes pH changes.
heat must be absorbed in order to break hydrogen bonds and heat is released when hydrogen bonds form. Lots of heat is used to disrupt hydrogen bonds before water molecules can move faster. the temperature of water goes down, lots of hydrogen bonds form, and release energy as heat.
explain how hydrogen bonding contributes to water's high specific heat.
H+ concentration is greater in pH of 8
explain the difference between a pH of 8 and a pH of 12 in terms of H+ concentration.
water is less dense as a solid than a liquid
explain why ice floats
molecules as large as proteins can dissolve in water as well as biological fluids, sap, and liquid in cells
explain why water is such a fine solvent
A lipid consisting of three fatty acids linked to one glycerol molecule; also called a triglyceride.
fat
hydrophobic
fats and lipids are hydrophilic or hydrophibic
consists of a carboxyl group and a hydrocarbon chain, usually 16 or 18 carbon atoms in length
fatty acid
monomer of lipids
fatty acids
an alcohol composed of a 3-carbon chain, which can serve as the backbone for a triglyceride
gylcerol
hydrophobic
having no affinity for water; repels water
transfer from one body of matter to another
heat
the heat a liquid must absorb for 1 g to be converted to gas
heat of vaporization
Because organisms are made primarily of water, they resist rapid temperature changes. This useful quality is based on water's _____
high specific heat
Natural buffers enable living organisms to maintain _________________
homeostasis
adding certain solutes, acids and bases
how do you modify the concentrations of H+ and OH-?
1. the hydrogen atom leaves its electrons behind and is transferred as a proton, or hydrogen ion (H+) 2. molecule lost the proton is an hydroxide ion (OH-) 3. molecule with an extra proton is a hydronium ion (H3O)
how does a hydrogen atom in a hydrogen bond between two water molecules sift from one to the other?
four
how many emergent properties of water are there?
one molecule cannot have a hydrogen bond on its own, but it can hydrogen bond to at most four other water molecules
how many hydrogen bonds can a single water molecule form?
more than 800 planets; there is evidence that a few of them have water vapor
how many planets have been found outside of our solar system?
100; (10x10)
how many times more acidic is a pH of 3 compared to a pH of 5?
10,000; (10x10x10x10)
how many times more basic is a pH of 12 compared to a pH of 8?
about 25%
how much of human generated CO2 is absorbed by the oceans?
sphere of water molecules around each dissolved ion
hydration shell
The partial negative charge at one end of a water molecule is attracted to the partial positive charge of another water molecule. What is this attraction called
hydrogen
Water has surface tension because ...
hydrogen bonds between surface water molecules resist being stretched.
In a neutral solution the concentration of _____.
hydrogen ions is equal to the concentration of hydroxide ions
A chemical reaction that breaks apart a larger molecule by adding a molecule of water
hydrolysis reaction
H3O+
hydronium ion
Less water molecules in any volume of _________ than in the same volume of liquid water
ice
constant and can be written as [H+][OH-]=10^-14
in any aqueous solution at 25 degrees celsius, the product of H+ and OH- is _______
oxygen; hydrogen
in the water molecule, the electrons of the polar covalent bonds spend more time near the ______ than the ______
An acid is a substance that _____.
increases the hydrogen ion concentration of an aqueous solution
Formed when one or more electrons are transferred from one atom to another; A chemical bond resulting from the attraction between oppositely charged ions.
ionic bond
Heat needed to raise 1 liter of water 1 degree Celsius
kilocalorie
the energy of motion
kinetic energy
When water freezes, Hydrogen bonds are no longer breaking and reforming and they are frozen in a ___________ arrangement
lattice
In a gaseous state, water has the _________ number of Hydrogen Bonds
least
sum of all atoms
molecular weight
small unit that can join together with other small units to form polymers
monomers
monomer of carbohydrates: glucose, fructose, galactose: single simple sugars
monosaccharides
A fatty acid with one double bond between carbon atoms
monosaturated fatty acid
In a solid state, water has the ___________ number of Hydrogen Bonds
most
6 to 8
most biological fluids have pH values in the range of ____ to _____
ranges from 6 to 8
most biological fluids have what pH value?
hydrophilic
most carbohydrates are hydrophilic or hydrophobic
What makes water molecule more structured than other molecules?
multiple hydrogen bonds
the hydrogen bond that it has results in a nonpolar covalent bond; hydrophobic molecules related to oils are a big part of cell membranes and are hydrophobic so the membrane does not dissolve
oil floating in water- explain in terms of hydrogen bonding
Examples of nonpolar molecules
oils, waxes, and fats
hydrogen bonding
oppositely charged regions of neighboring water molecules are attracted to each other; each molecule can hydrogen bond to multiple partners and they constantly change
_________________ attract
opposites
covalent bond formed between amino acids; The chemical bond that forms between the carboxyl group of one amino acid and the amino group of another amino acid
peptide bond
The bonds connecting amino acids together to form polypeptide chains.
peptide bonds
PO4
phosphate group
a lipid consisting of a glycerol bound to two fatty acids and a phosphate group. also a component of biological membranes having a hydrophilic head and hydrophobic tails.
phospholipids
In water, the electrons are not shared equally creating a ___________ molecule
polar
The unequal sharing of electrons within a water molecule makes the water molecule _____.
polar
a molecule in which one side of the molecule is slightly negative and the opposite side is slightly positive
polar molecule
hydrogen bonds with each other
polarity allows water molecules to form what
are long chains of amino acids joined together by peptide bonds
polypeptide chains
Has many double bonds. Not packed tightly at all. Liquid at room temp. Double bond susceptible to oxidation. Ex: Vegetable Oil.
polysaturated fatty acids
Hydrogen atoms form between adjacent water molecules because the ______________ charged hydrogen end of one water molecule attracts the _______________ charged oxygen end of another molecule
positively; negatively
The first level of protein structure; the specific sequence of amino acids making up a polypeptide chain.
primary structure
as a liquid evaporates, its remaining surface cools
process of evaporative cooling
determines how (or if) it works
protein's conformation
A fatty acid in which all carbons in the hydrocarbon tail are connected by single bonds, thus maximizing the number of hydrogen atoms that can attach to the carbon skeleton. a long-chain hydrocarbon with single covalent bonds in the carbon chain; the number of hydrogen atoms attached to the carbon skeleton is maximized
saturated fatty acid
Because of ocean acidification, the price of which of the following foods is most likely to increase?
shellfish
hormones and other chemical messengers that coordinate body activities by helping communicate between cells
signal proteins
liquid completely homogeneous of two or more substances
solution
Water is called the universal _______________
solvent
the dissolving agent of a solution
solvent
Water having a high __________________ allows water to resist changes in state, retain heat energy much more than other substances, and moderate temperatures of a nearby area
specific heat
the amount of heat that must be absorbed or lost for 1 g of that substance to change its temperature by 1°C
specific heat
1 cal/(g • °C)
specific heat of water
A type of lipid characterized by a carbon skeleton consisting of four rings with various functional groups attached. cholesterol and hormones are examples
steroid
evaporation of water into the atmosphere from leaves and stems of plants
transpiration
hemoglobin in red cells that delivers O2 to working muscles and tissues throughout the body.
transport protein
Energy, because DNA strands are held together by the hydrogen bonds
two DNA strands must first separate into two single strands for DNA to be replicated. Do you think the process of strand separation requires energy, or do you think the strands can separate spontaneously?
high surface tension
water has an unusually ______ ________ _______ due to hydrogen bonding between the molecules at the air water interface and to the water below
Why will water not change its temperature often?
water has high specific heat
Polarity allows what
water molecules to form hydrogen bonds with each other
4°C
water reaches its greatest density at
human activities such as burning fossil fuels
what threatens air quality?
H+ and OH-
what two ions form when water dissociates?
a polar molecule (overall charge is unevenly distributed)
what type of molecule is a water molecule
because of its high specific heat
why does water resists changing its temperature?
- ice forms a crystalline structure - ice has fewer molecules per volume - it is less dense
why ice floats
water reaches its greatest density at 4 degrees celsius
why is 4 degrees celsius a critical temperature with water?
because of its polarity
why is water a versatile solvent?
Which statement is true of water's tensile strength?
(a)It results from hydrogen bonding. (b) It helps to pull water through plants. (c) It involves both cohesion and adhesion.
What pH values are considered acidic?
0 to 7
What is the pH of battery acid?
1
The amount of energy that must be absorbed or lost to raise or lower the temperature of 1 g of liquid water by 1°C _____.
1 calorie
What atoms is water made of?
1 oxygen and 2 hydrogen
Which factor is important in making it possible to cool yourself by sweating? Think carefully!
1. Molecules collide with varied angles and speeds. 2. Hydrogen bonds are relatively weak.
Base
1. NaOH -> Na+ + OH- 2. NH3 + H2O -> NH4 + OH-
Four ways water properties contribute to life environment
1. cohesion and adhesion 2. ability to moderate temperature 3. Expansion upon freezing 4. Versatility as a solvent
1000
1kcal = ________ cal
How many partial negative charged areas are in water?
2
What is the pH of lemon juice?
2
ow much carbon dioxide from the atmosphere is absorbed by the oceans on a daily basis?
20 million metric tons
-moderates earth's climate (helps us live) -accounts for severity of steam burns -releases heat and forms rain
3 effects of heat vaporization on living organisms
fats, phospholopipids, steroids
3 types of lipids
How many hydrogen bonds can water make?
4
In what temperature does the water reach its greatest density?
4 degrees Celsius
Neutral ph
7
What is the neutral pH?
7
What pH values are considered basic?
7 to 14
Select the statement that best describes a buffer.
A buffer resists change in pH by accepting hydrogen ions when acids are added to the solution and donating hydrogen ions when bases are added.
0.092 g
A mole of ethyl alcohol weighs 46 g. How many grams of ethyl alcohol are needed to produce 1 L of a 2-millimolar (2 mM) solution?
Which of the following effects can occur because of the high surface tension of water?
A raft spider can walk across the surface of a small pond.
Hydrogen Bond
A relatively weak bond between the partial negative side of one molecule and partial positive side of another molecule
100 times more H⁺
A solution at pH 6 contains _____ than the same amount of solution at pH 8.
buffer
A substance that minimizes changes in the concentration of H⁺ and OH⁻ in a solution is a _____.
clinging of a substance to another
Adhesion
the clinging of one substance to another
Adhesion
the clinging of one substance to another substance
Adhesion is best described as _____.
Water is both cohesive and ______________
Adhesive
An organic molecule containing a carboxyl group and an amino group; serves as the monomer of proteins.
Amino Acid
amino group w/ carboxyl group
Amino Acids
-NH 2 a N bonded to two H and the carbon skeleton.
Amino Group
the solute is dissolved in water; water is the solvant
Aqueous solution
solvent, solute, nonpolar.
As a result of electron configuration of a water molecule, water is a great _______ because water can break up and surround a ______, as long as it is not ______, dissolving it into solution
True
As temperature drops the bonds between water molecules are less likely to break
evaportates
As water ____ from the pores in the leaves,more water is pulled up from below resulting in a constant supply of water moving up through the vessels of a plant
At any temperature because temperature is just an average quantity. Even at low temperatures, the speediest molecules can escape into the air. Its just the difference in speed. Liquid heated --> Average kinetic energy increases & liquid evaporates quickly
At what temperature can evaporation occur?
A substance that decreases the hydrogen ion concentration in a solution; ph greater than 7
Base
Gives off excess Hydroxyl Ions (OH) when dissolved in water; removes excess (H) ions
Base
Important to suit environment for life. Allows life under water.
Benefits of Ice being Less Dense
Example of adhesion
Between water and cell wall
C 6
Carbon
A large polysaccharide composed of many glucose monomers linked into cable-like fibrils that provide structural support in plant cell walls.
Cellulose
A substance (made of sugars) that is common in the cell walls of many organisms; polysaccharide consisting of glucose monomers that reinforces plant-cell walls
Cellulose
polymer of glucose, able to form microfibrils in plants/most abundant organic compound
Cellulose
A structural polysaccharide found in many fungal cell walls and in the exoskeletons of arthropods.
Chitin
holding a substance together
Cohesion
Water is both _________ and adhesive
Cohesive
Coffee is the solvent and sugar is the solute.
Consider coffee to which you have added sugar. Which of these is the solvent? Which is the solute?
Water bugs floating on water etc.
Contribution of Surface Tension
Adhesion of water by H bonds to the molecules of cell walls helps counter downward pull
Contributions
Electrons are shared between two atoms
Covalent Bond
Heat of Vaporization-- quantity of heat a liquid must absorb for 1g of it to be converted from the liquid to the gaseous state. 1. moderate earth's climate 2. severity of steam burns on skin 3. sweat in humans
Define Heat of Vaporization. Explain at least three effects of this property on living organisms
1. Moderate climate (lots of solar heat absorbed --> evaporation --> condensation) 2. Severity of steam burns: Heat energy is released when steam condenses into liquid on the skin.
Effects of Water's High Heat Vaporization
Covalent Bond
Electrons are shared between two atoms
Ionic bonds
Electrons are transferred between two atoms creating positively and negatively charged atoms, which then attract to each other. Na+ + Cl- --> NaCl
Why is there a partial negative charge near the hydrogen atom?
Electrons spend less time there
Why is there a partial negative charge near the oxygen atom?
Electrons spend more time there
specialized macromolecules that speed up chemical reactions in cells
Enzymes
When heated and kinetic energy increases, molecules vibrate rapidly and evaporate, and as they evaporate from the surface, heat is taken with it, cooling off the surface
Evaporative Coolant
As liquid evaporates, the surface of the liquid that remains behind cools down (temp. decreases) -Because the hottest molecules are most likely to leave as a gas.
Evaporative cooling
as a liquid evaporates the surface of the liquid that remains behind cools down
Evaporative cooling
remains of a liquid cool down
Evaporative cooling
presence of sulfur oxides/nitrogen oxides and gaseous compounds react with air and goes into lakes, oceans, and soil, affecting animal life
Extent of acid precipitation
A large lipid molecule made from an alcohol called glycerol and three fatty acids; a triglyceride. Most fats function as energy-storage molecules.
Fat
1. Burning of fossil fuels 2. Ocean acidification
Give two reasons precipitation is more acidic today than compared to 1900
Base
Gives off excess Hydroxyl Ions when dissolved in water; removes excess H
An extensively branched glucose storage polysaccharide found in the liver and muscle of animals; the animal equivalent of starch.
Glycogen
animal storage of glucose
Glycogen
acid
H+ ions
Form of energy that flows between two substances due to differences in temp. Thermal energy in the transfer from one body to another. Unit: Calorie
Heat
What must be absorbed to break hydrogen bond?
Heat
thermal energy in transfer from one body of matter to another
Heat
total kinetic energy due to molecular motion
Heat
The quantity of heat a liquid must absorb for 1 gram of it to be converted from liquid to gas.
Heat Vaporization
the quantity of heat a liquid must absorb for 1 g of it to be converted from the liquid to the gaseous state
Heat of vaporization
Water has __________ surface tension
High
Example of an acid
Hydrochloric acid
-Reversible reaction
Hydrogen Atoms in a Hydrogen Bond with Water Molecules can shift from one to another.
Systems for temperature regulation would have to be much more efficient.
Imagine that organisms consisted of 70-95% alcohol instead of 70-95% water. Alcohol's specific heat is about half that of water. How would living things be different?
the oxygen atom in one water molecule and a hydrogen atom in another water molecule
In a group of water molecules, hydrogen bonds form between _____.
molecules are hydrophobic
Insoluble
Organic compounds with the same molecular formula but different structures and, therefore, different properties.
Isomers
Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen.
Lipids
oxygen attracts electrons more than hydrogen does
Most of water's unique features (for example, its versatility as a solvent, ability to moderate temperature, and cohesive behavior) result from the fact that _____.
Nitrogen
N (element)
Oxygen has partial what charge?
Negative
[H+]=[OH-] 7
Neutral pH
Could "life" exist without the presence of water?
No
Dissolve when water molecules surround & form H bonds with them.
Non-ionic compounds dissolving - POLAR MOLECULES (ex. Sugar)
What makes a substance hydrophobic?
Nonionic and nonpolar
a process when C0₂ dissolves in seawater, and forms carbonic acid (lowers the ocean pH)
Ocean acidification
Neutral is located at pH 7. Acidity increases from 7 to 0. Baseness increases from 7 to 14. Pure water has a pH of 7, urine has a pH of 6, gastric juice has a pH of 2, and bleach has a pH of 13.
On the pH chart, label pH 1-14. Label neutral, acid, and base. Indicate the locations of pure water, urine, gastric juice, and bleach.
Carbon-based molecules that usually contain hydrogen atoms in addition to carbon.
Organic Compounds
carbon based molecules
Organic Compounds
Water has a _______________________ charge near the oxygen atom
Partial Negative
-OPO3^-2/consists of a phophorous atom bonded to four oxygen atoms. Usually ionized and attached to the carbon skeleton by one of its oxygen atoms. example=organic phosphates.
Phosphate Group
-OPO3^2- a P atom bonded to four O atoms.
Phosphate Group
contain a phosphate group and attach to 2 fatty acids rather than three
Phospholypids
Which statement must be mentioned in explaining why amphipathic molecules line up at a water surface?
Polar groups attract one another.
A molecule that has electrically charged areas
Polar molecule
Unequal sharing of electrons/uneven charge distribution
Polar molecule
Chemical reactions
Require energy to begin, usually require a catalyst to speed up the process, reversible, and occur in liquid environments such as water
water molecules stay close to each other
Result of hydrogen bonding
stability of temperatures in lakes and ponds
Result of water's high heat of vaporization?
fatty acid containing only single bonds
Saturated Fatty Acid
Solution- Liquid that is a completely homogeneous mixture of two or more substance Solvent- Dissolving agent Solute: Substance that's dissolved Aqueous Solution: Solute that is dissolved in water solvent.
Solution, Solvent, Solute, Aqueous Solution
dissolving agent of a solution WATER IS THE UNIVERSAL SOLVENT
Solvent
the substance in which a solute is dissolved
Solvent
their molecules have no charges or partial charges to which water molecules can adhere
Some substances, such as oil and gasoline, will not dissolve in water because _____.
Amount of heat absorbed or lost for 1g o that substance to change its temp by 1 degree Celsius. Water has a HIGH specific heat.
Specific Heat
Why does ice float in liquid water?
Stable hydrogen bonds keep water molecules of ice farther apart than water molecules of liquid water
A storage polysaccharide found in the roots of plants and certain other cells; a polymer of glucose.
Starch
A storage polysaccharide in plants consisting entirely of glucose.
Starch
a storage polysaccharide in plants
Starch
A type of lipid whose carbon skeleton is in the form of four fused rings with various chemical groups attached; examples are cholesterol, testosterone, and estrogen.
Steroid
lipids containing 4 fused rings
Steroids
HCL & NaOH Dissociate completely when mixed with H20 One sided reaction arrow
Strong acid/base
The oxygen is in the center (red), with hydrogen on either side (white).
Study the water molecules at the right. On the central molecule, label oxygen (O) and hydrogen (H).
Glucose+Fructose
Sucrose
ex) Ice cools hot water by absorbing thermal energy (not by releasing).
TE passes from warm to cooler object until the two are the same temperatures.
Average kinetic energy of the molecules in a body of matter
Temperature
Measure of energy (in degrees) of average KE (thermal energy) of atoms in body of matter -Higher temp = higher KE -Regardless of volume
Temperature
a measure of energy that represents average kinetic energy of molecules in a body of matter
Temperature
cohesion, hydrogen
The _____ of the water molecules, resulting from ____ bonds between water molecules, causes a movement of water through the plants vessels as it moves up from the roots.
False
The bonds between water molecules are stable.
A calorie is the amount of heat needed to raise the temperature of 1g of water by 1ºC and also the amount of heat released by 1g of water when it cools by 1ºC. One calorie is equal to 4.184J.
The calorie is a unit of heat. Define Calorie.
Solvent
The charged ends of a water molecule allow it to surround a solute in solution.
True
The fluid nature of water is due to hydrogen bonds continually breaking and reforming.
False
The high specific heat of water means that we only lose a small amount of heat when the sweat on our skin evaporates
7
The internal pH of most living cells is close to _____
The solutes in blood lower its freezing point
The liquid portion of blood of animals, including humans, is a watery solution containing many dissolved solutes, such as Na+ and Cl−. Would you predict that the freezing point of blood is above, below, or the same as that of water?
The cities of Portland, Oregon, and Minneapolis, Minnesota, are at about the same latitude, but Minneapolis has much hotter summers and much colder winters than Portland. Why?
The ocean near Portland moderates the temperature.
specific heat
The reason that coastal climates are more moderate than inland climates is due primarily to water's high _____.
molecular mass
The sum of the atomic masses of all the atoms of a molecule is its
Evaporated cooling
The temperature of water rises slowly due to its high specific heat; requiring a lot of energy to convert liquid water to water vapor.
polar molecule
The unequal sharing of electrons between the oxygen and the hydrogen atoms within a water molecule makes water a ____ molecule
High surface tension in water
There are fewer molecules at the surface of a pool of water so the molecules have a greater attraction to each other
How do organisms resist changes in pH?
They use buffers
An unsaturated fat, formed artificially during hydrogenation of vegetable oils, which is linked to health risks.
Trans Fats
a form of fat that recent research associates with health risks
Trans Fats
Evaporation of water through plant leaves
Transpiration
_______________ is the process of water evaporating from the leaves of plants through the stomata
Transpiration
Pertaining to fats and fatty acids whose hydrocarbon chains lack the maximum number of hydrogen atoms and therefore have one or more double covalent bonds. Unsaturated fats and fatty acids do not solidify at room temperature.
Unsaturated Fatty Acid
fatty acid containing one or more double bonds
Unsaturated Fatty Acid
what makes water a polar molecule?
V shape and unequal sharing
Liquid to gas
Vaporization
Liquid ---> vapor Molecules need to move fast enough can overcome attraction and depart into a vapor.
Vaporization/ Evaporation
universal solvent
WATER
What is solvent in lemonade?
Water
What molecule is this?
Water
True
Water bathes organs in fluid, which provides protection and support
Although this question is rhetorical, the concentration of [H+] = 10-7
Water has a pH of 7. pH is defined as the negative log of the hydrogen ion concentration [H+]. Can you now see how water is assigned a pH of 7?
the opposite ends of the molecule have opposite electrical charges
Water is a polar molecule. This means that _____.
polar
Water is a very versatile solvent because water molecules are _____.
Reversible rxns Accept and release back H+
Weak acid/base
[H+]= 10E-7 [OH-]=10E-7 [H+][OH-]=10E-14
What are the concentrations of H+ and OH- in a neutral solution at 25 degrees C?
Polarity of the water molecule! Charge distribution where the O are slightly (-) and H are slightly (+)
What causes hydrogen bonding with water molecules?
All are properties related to hydrogen bonding.
What do cohesion, surface tension, and adhesion have in common with reference to water?
10^-6
What is the OH− concentration at pH 8?
Evaporative Coolant
When heated and kinetic energy increases, molecules vibrate rapidly and evaporate, and as they evaporate from the surface, heat is taken with it, cooling off the surface
The oil would be in the center of the soap micelles.
When oil dissolves in soap, where is the oil found?
It has increased by 10,000 times.
When the pH of a solution shifts from 7 to 3, how has the hydrogen ion concentration changed?
Buffers.
Why does the addition of acid have less of an effect on the pH of blood than the pH of water?
Hydrogen bonding
Why does water expand when it solidifies, whereas other liquids contract when they solidify??
hydrogen bonds between molecules at the air-water interface and the water below
Why does water have such a high surface tension?
It has numerous slightly (+) and (-) regions that can form H Bonds with H20. Water adheres to cellulose fibers. -That is why cotton is good at drying things. -Cellulose is also apart of plant walls (adhesion of h20 to hydrophilic walls helps h20 move up the plant against gravity)
Why is Cellulose hydrophilic?
More carbon dioxide causes an increase in carbonic acid (H₂CO₃), which leads to a decrease in the concentration of carbonate ion (CO₃²⁻).
Why is the increasing amount of carbon dioxide being taken up by the oceans a cause for concern?
Overall charge unevenly distributed
Why is water considered polar?
the oxygen region is partial negative and the hydrogen region is partial positive
Why is water considered polar?
Oxygen is more electronegative than hydrogen and the electrons of the polar bonds spend more time near oxygen thus, making oxygen more negativity charged and hydrogen more positively charged
Why is water polar?
Most substances dissolve in ater. No need for ionic for ionic compounds
Why is water such a fine solvent?
contributes to the fitness of the Earth including other water properties like its cohesion, ability to stabilize temperature, expansion upon freezing, as well as its versatility as a solvent
Why is water's polarity significant?
Oil molecules cannot form hydrogen bonds with water and thus behave hydrophobically, because there is a prevalence of relatively nonpolar covalent bonds—in this case, bonds between the carbon and hydrogen, which share electrons almost equally.
You already know that some materials, such as olive oil, will not dissolve in water. In fact, oil will float on top of water. Explain this property in terms of hydrogen bonding.
surface tension
You can fill a glass of water to just slightly above the rim without it spilling over the glass. What property of water best explains this phenomenon?
acid
_____ is formed when a Carboxyl Group is added
alcohol
_____ is formed when a Hydroxyl Group is added
starch
_____ made up of only glucose monosacchrides used for storage in plants
water's
_____ unique emergent properties help make Earth suitable for life
solution
a liquid that's a homogenous mixture of two or more substances
Dissolving is best described as ..
a mingling of molecules and/or ions
[H+] is 10^-7, so pH=-(-7)=7
a neutral aqueous solution
acid
a substance that increases the hydrogen ion concentration of a solution
solute
a substance that is dissolved in a solution
base
a substance that reduces the hydrogen ion concentration of a solution
Buffers work best when ...
about half of the buffer molecules are dissociated.
What is the main reason that the oceans are becoming more acidic?
absorption by the oceans of carbon dioxide generated by burning fossil fuels
a substance that increases the H+ concentration of a solution
acid
less than 7
acidic
Proton donors
acids
increase H+ concentration
acids
increase hydrogen concentration
acids
an attraction between water molecules and other substances (water and other)
adhesion
is an attraction between different substances, for example, between water and plant cell walls
adhesion
Which property of water allows a paper towel to pick up a puddle of water?
adhesion of water molecules to other kinds of molecules
monomers of proteins
amino acids
A functional group that consists of a nitrogen atom bonded to two hydrogen atoms
amino group
Opposites _____________
attract
When water freezes, Hydrogen bonds are no longer _________________________ and they are frozen in a lattice arrangement
breaking and reforming
substance that minimizes changes in H+/OH- concentration
buffers
cohesion (water and water) adhesion (water to surface of xylum)
capillary action
What is the chemical reaction responsible for the oceans becoming more acidic?
carbon dioxide reacts with seawater, forming carbonic acid
The chain of carbon atoms that forms the structural backbone of an organic molecule.
carbon skeleton
A chemical group present in aldehydes and ketones and consisting of a carbon atom double-bonded to an oxygen atom. C=O a chemical group consisting of a carbon atom linked by a double bond to an oxygen atom
carbonyl group
A functional group present in organic acids and consisting of a single carbon atom double-bonded to an oxygen atom and also bonded to a hydroxyl group. COOH
carboxyl group
solvent is coffee; solute is sugar
coffee with sugar added; which is solvent? solute?
helps the transport of water against gravity in plants
cohesion
Water molecules can form hydrogen bonds with _____.
compounds that have polar covalent bonds
equal
concentrations of H+ and OH- are _____ in pure water
ice is less dense as a solid than a liquid. If ice sank, eventually all ponds and bodies of water would freeze over and kill life. the ice stays onto so that it doesn't freeze beneath and life can exist under the ice
consider what would happen if ponds and other bodies of water accumulated ice at the bottom and describe why this property of water is important
In water, hydrogen and oxygen atoms are held together by _____________ bonds
covalent
antibodies of the immune system
defensive proteins
A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule.
dehydration reaction
sugar in DNA; five carbon sugar
deoxyribose
water enters the root
diffusion
strong acids and bases
do strong or weak acids and bases dissociate completely in water?
increase molecules vibrate faster
does heat energy increase or decrease kinetic energy?
Ice __________________ in liquid water
floats
Each water molecule is joined to _____ other water molecules by ____ bonds
four , hydrogen
1. cohesive behavior 2. ability to moderate temperature 3. expansion upon freezing 4. versatility as a solvent
four emergent properties of water:
process by which a gene produces its product and the product carries out its function
gene expression
an alcohol with three carbons each bearing a hydroxyl group
glycerol
Liquid water
has a heat of vaporization higher than that of most other substances
To make a buffer, you need to ...
have a weak acid or a weak base half ionized in water.
hydrophilic
having an affinity for water; can dissolve in water, but not always
sphere of water molecules around dissolved ions
hydration shell
cohesion
hydrogen bonds hold the substance together, contributes to transport of water and dissolved nutrients against gravity in plants
cohesion
hydrogen bonds hold water molecules together, a phenomenon called
hydrogen atom leaves its electron behind and is transferred as a proton
hydrogen ion (H+)
H30+
hydronium ion
the molecule with the extra proton, often represented as H+
hydronium ion (H3O+)
one that has an affinity for water
hydrophilic substance
"water loving" has an affinity for water
hydrophillic
"water fearing" does not have an affinity for water
hydrophobic
one that does not have an affinity for water
hydrophobic substance
water loving/hating
hydrophobic/philic substances
What does acid remove?
hydroxide ion (OH-)
molecule that lost the proton
hydroxide ion (OH-)
OH-
hydroxyl group
In an organic molecule, a functional group consisting of a hydrogen atom bonded to an oxygen atom. alcohol
hydroxyl group (-OH)
500,000 cal 500"cal" = 500kcal = (500x1000) = 500,000
if a food claims it has 500 calories, how many calories is it really?
Though you add heat, the temperature of boiling water remains constant because ...
it takes energy to break hydrogen bonds
diverse compounds that are grouped together because they don't mix well with water.
lipids
Less water molecules in any volume of ice than in the same volume of __________________
liquid water
an anzyme found in sweat,tears and saliva
lysozyme
long-term energy storage. (a gram of fat stores more than 2X as much energy as a gram of polysaccharide.
main function of fats
hydrophobic molecules related to oils oils
major ingredients of cell membranes
thermal energy depends on
mass and temperature
concentration measured by number of mols/liter of solution
molarity
the molecular weightof a substance expressed in grams (6.02 x 10^23)
mole
sum of all masses of all atoms in a molecule
molecular mass
7
neutral
Hydrophobic substances such as vegetable oil are _____.
non polar substances that repel water
monomers of nucleic acids
nucleotides
monomers that make up nucleic acides (3 parts: sugar, phosphate group, nitogen base (5 different ones) ).
nucleotides
CO2 dissolved in sea water forms carbonic acid
ocean acidification
CO2 dissolved in seawater which forms carbonic acid
ocean acidification
when CO2 dissolves in seawater, it reacts with water to form carbonic acid, which lowers ocean pH
ocean acidification
Examples of hydrophobic molecules
oils, waxes, and fats
Why is water polar?
oxygen is more electronegative than hydrogen
pH= -log (H+)
pH
Describes how acidic or basic a solution is
pH scale
measures concentration of H+ (scale from 1-14)
pH scale
measures how acidic or base a substance is (0-14)
pH scale
scale with values from 0 to 14, used to measure the concentration of H+ ions in a solution
pH scale
As H+ concentration increases
ph decreases
hydrogen bonding
polar covalent bonds in water results in
heat of vaporization
quantity of heat a liquid must absorb for 1g of it to convert to gas
The fourth level of protein structure; the shape resulting from the association of two or more polypeptide subunits.
quaternary structure
built into cell membranes and transmit signals into cells
receptor proteins
Either an alpha helix or beta pleated sheet.
secondary structure
NaCl (table salt)
sodium chloride
Water has a higher density as a liquid than as a ____________
solid
the substance dissolved by the solvent
solute
the substance that is dissolved
solute
a liquid that is a completely homogenous mixture of substances
solution
a liquid that is a completely homogenous mixture of two or more substances
solution
dissolving agent
solvent
the protein of egg white which serves as a source of amino acides for developing embryos
storage proteins
completely ionized when dissolved in water
strong acids and bases
found in hair and the fibers that make up connective tissues (tendons and ligaments)
structural proteins
bodies of water can absorb tons of heat from the sun. when it gets colder outside, the water can warm the air, which makes a milder climate and stabilizes ocean temperatures. This is important to life because marine life has a favorable environment and keeps temperature fluctuations within limits that permit life.
summarize how water's high specific heat contributes to the moderation of temperature. How is this property important to life?
A measure of how difficult it is to stretch or break the surface of a liquid
surface tension
Cohesion of water molecules along a surface produces what
surface tension
is a measure of how difficult it is to break the surface of a liquid
surface tension
Water can absorb or release a large amount of heat with only a s light change in its own...
temperature
represents the average kinetic energy of the molecules in a body of matter
temperature
The third level of protein structure; the overall, three-dimensional shape of a polypeptide due to interactions of the R groups of the amino acids making up the chain.
tertiary structure
adhesion
the clinging of one substance to another, helps counter gravity
Consider two solutions: solution X has a pH of 4; solution Y has a pH of 7. From this information, we can reasonably conclude that _____.
the concentration of hydrogen ions in solution X is 1000 times as great as the concentration of hydrogen ions in solution Y
solvent
the dissolving agent of a solution; water is the most versatile
The partial negative charge in a molecule of water occurs because _____.
the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus
determined by amino acid composition
the functions of all these different types of proteins depend on their specific shape
water
the only common substance to exist in the natural environment in all three physical states of matter is
pH=-log[H+]
the pH of a solution is defined by the negative logarithm of H+, which can be written as?
water molecule
the structure of the _____ ________ allows it to interact with other molecules
evaporation
the transformation from a liquid to a gas
Heat energy
thermal energy
the kinetic energy associated with random motion of atoms or molecules
thermal energy
same as heat
total kinetic energy
a lipid made of three fatty acid molecules and one glycerol molecule
triglyceride
linking 3 fatty acides to glycerol produces a fat-energy storage
triglyceride
True or False: bases will give off O ions to make it more basic, H ions to make it more acidic
true
True or false: Polar attractions are weaker than covalent bonds
true
a fatty acid whose hydrocarbon chain contains one or more double bonds
unsaturated fatty acid
amount of heat needed to turn liquid into gas
vaporization
An example of Hydrophobic is
vegetable oil
water molecules dissociate at the same rate at which they are being reformed
wate is in a state of dynamic equilibrium, which means?
warmer air; cooler air
water absorbs heat from _____ ____ and releases stored heat to _____ ____
large; slight
water can absorb or release a _______ amount of heat with only a ______ change in its own temperature
nonionic polar
water can also dissolve compounds made of ________ _______ molecules
Concentration of H+ =10^-7; log of 10^-7=7 so pH=7
water has a pH of 7. pH is defined as the negative log of the hydrogen ion concentration [H+]. Can you now see how water is assigned a pH of 7?
Which property of water allows a water strider to walk on water?
water's high surface tension
1. Cohesive and adhesive behavior 2. Ability to moderate temperature 3. Expansion upon freezing 4. Universal solvent
water's properties that facilitate an environment for life
only partly ionized in their solution
weak acids and bases
hydrogen bonding
what can water's high specific heat be traced to?
pH scale
what do biologists use to describe whether a solution is basic or acidic?
a weak acid and its corresponding base, which combine reversibly with H+ ions
what do most buffer contain?
reversibly release and accept back hydrogen ions, but can still shift the balance of H+ and OH- away from neutrality
what do weak acids and bases do?
calcification (production of calcium carbonate) by many marine organisms, including reef-building corals
what is carbonate required for?
adhesion; the water molecules are sticking to each other
what is demonstrated when you see beads of water on a waxed car hood?
10^-7 M
what is the concentration of each ion in pure water at 25 degrees celsius?
close to 7
what is the internal pH of most living cells?
CO2
what is the main product of fossil fuel combustion?
6
what is the pH for rainwater?
1
what is the pH of battery acid?
4
what is the pH of black coffee and tomato juice?
2
what is the pH of gastric juice?
11/12
what is the pH of household ammonia?
13
what is the pH of household bleach?
10
what is the pH of milk of magnesia?
14
what is the pH of oven cleaner?
7
what is the pH of saliva, pure water, and human blood?
8
what is the pH of seawater?
3
what is the pH of vinegar, wine, cola?
water
what is the solvent of life?
water
what makes life possible on earth?
mars
what planet in our solar system has been found to have water?
acidic solutions
what type of solution has pH values less than 7?
basic solutions
what type of solution has pH values more than 7?
all bodies of water would eventually freeze solid, making life impossible on Earth
what would happen if ice sank?
each ion is surrounded by a sphere of water molecules called a hydration shell
when an ionic compound is dissolved in water
absorbed
when hydrogen bonds break heat is ______
released
when hydrogen bonds form heat is _____
H+ ions combine with carbonate ions to produce bicarbonate
when seawater acidifies, what happens?
high surface tension of the water from the strength of the hydrogen bonds
which property explains the ability of a water strider to walk on water?
because hydrogen bonds in ice are more "ordered," making ice less dense than water
why does ice float in liquid water?
Is ice less dense than water?
yes
