Download Bio 12 Chapter 2 Test Review 1.Know the difference between ionic

Bio12
Chapter2TestReview
1.Knowthedifferencebetweenionicandcovalentbonds
Inordertocompleteoutershellsinelectronsbondscanbe
Ionic;oneatomdonatesorreceiveselectrons
Covalent;atomsshareelectrons
2.Knowwhatapolarcovalentbondis:
bondthathasUNEQUALsharingofelectrons
3.Beabletoexplainwhywaterisapolarmolecule
*Polarbondshavechargesoneitherendandoftenattracttoeachother
*Atoms‘hogging’theelectronshaveanelectronegativecharge,andatoms
‘lacking’electronshaveanelectropositivecharge
4.Explainwhatahydrogenbondisandwhyitisimportant
Electronegativeatomsononemoleculeareattractedtoelectropositiveatoms
onadifferentmolecule.FormHydrogenbonds.
5.Explaintheuniquecharacteristicsofwaterandexplainhowtheyareuseful
toorganisms(posteryoumade)
*Watermoleculesareattractedtootherpolarmolecules
cohesion–whenonewatermoleculeisattractedtoanotherwatermolecule
adhesion–whenpolarmoleculesotherthanwatersticktoawatermolecule(Steady
columnofwater)
*Waterwarmsupandcoolsdownslowly(highheatcapacity)
*Waterhasahighheatofvaporizationbecausesomanyhydrogenbondsmustbe
brokenforwatertoevaporate
*Asolutionconsistsofasolutedissolvedintoasolvent
*Water’shydrogenbondshelpitdissolveotherpolarmolecules
*FrozenWaterisLessDensethanLiquidWaterandfloatsonliquidwater
6.ExplainthedifferencebetweenanacidandabaseandwhatpHis.
pHistheMeasurementofAcidity(acid)orAlkalinity(base)ofaSolution.
ThepHscalegoesfrom0to14
-pH0isacidic
-pH7isneutral
-pH14isbasic
ThegreatertheH+concentration,
thelowerthepH
Thelowerthehydrogenionconcentration,thehigherthepH
7.Definebufferandexplainitsroleinbiologicalsystems
BuffersHelpKeepthepHofBodyFluidsRelativelyConstant
BufferSystem:thecombinationofaweakacidandthebasethatformswhenthe
aciddissolvesinwater
BybindingorreleasingH+’s,itmaintainsaconstantconcentrationoffreeH+’sinthe
solution
8.Explainhowdifferencesincarbonskeletonandattachedfunctionalgroups
causeorganicmoleculestohavedifferentchemicalproperties
Ahydrocarbonchaincanturnbackonitselftoformaringcompound,oraspiralor
aseriesoffoldsduetotheinteractionbetweentheatomsandthefunctionalgroups.
Functionalgroupsarespecificcombinationsofbondedatomsthatalwaysreactin
thesameway.
9.Explainthedifferencebetweenhydrophobicandhydrophilic
• Hydrophilic(water-loving)moleculesformhydrogenbondswithwater
• Hydrophobic(water-fearing)moleculesdonotformhydrogenbondswith
water
10.Differentiatebetweenthefourclassesofmacromoleculesandbeableto
identifythemfromapictureoftheirstructure
1) Carbohydrates
monomer
2) Proteins
polymer(Chitin)
3) Lipids
Which Is a Source of Unsaturated Fatty Acids?
Linseed Oil
Beef Fat
Est
4) NucleicAcids-formedwithribosesugar,phosphateandnitrogenousbase
P P
P
P 11.Explaintherelationshipbetweenmonomersandpolymersofthe
macromolecules(glucosevsstarch,aminoacidsandproteins…)
Monomerorbuildingblocks
polymer
glucose
Starch,celluloseorglycogen,chitin
Aminoacid
proteins
Glycerolandfattyacids
Lipids(alsoSteroids,Waxes)
Nucleotides(sugar,phosphategroupand DNA,RNA,ATP
nitrogenousbase)
12.Differentiatebetweendehydrationsynthesisandhydrolysisandmake
suretounderstandwhetherwaterisaddedorremovedandwhetherenergyis
releasedorrequiredinthereaction
Bytakingoutawatermolecule(hydroxyl-OHfromoneandHydrogen-Hfrom
anothermonomer)betweenbuildingblocks,youcanlinkmonomersorbuilding
blockstomakealargermolecule(polymer).Thisiscalleddehydration
synthesis.Energyisrequired(endergonic)
Byaddingawatermolecule,youcancutthelargerpolymerintoitsindividual
monomersorbuildingblockcomponents.Thisiscalledhydrolysis(watercutting).
Energyisgivenoff(exergonic)
13.Knowthedifferencebetweenglycogenandcellulose
Glucoseconvertstoalong-chaincarbohydrate,Glycogen,tostoreintheliver,in
animals.
Glucoseconvertsintoalong-chaincarbohydrate,cellulose,tostoreinthecellwalls
ofplantsthatgiveitstructuralsupport.
14.Explainwhyfatsandoilsareinsolubleinwater
Bothfatsandoilsarehydrophobic.Thatis,theydonotattractwatersincethereis
no–or+end.Theyarenon-polar.
15.Whatisthedifferencebetweensaturatedandunsaturatedfattyacids?
Saturatedfatscontainnodoublebondsbetweenthecarbonsinthechainofthefatty
acid.
Unsaturatedfatscontaindoublebondsbetweenthecarbons.Theyarefluidasa
resultofthespacecreatedbetweenthechainsduetothekinkswherethedouble
bondsare.
16.Distinguishbetweenphospholipidsandtriglycerides
Triglycerideshaveaglycerolbackboneandthreefattyacidchainsattached(FAT)
PhospholipidshaveaglycerolbackboneandTWOfattyacidchainsandaphosphate
group
17.Whatarewaxes?Whataresteroids?
Waxes:lipidsthatprotectfromwater(plants,ears)andenergystorageinplankton;
longchainfattyacidattachedtoanalcohol,solidatroomtemperature
Steroids:lipidsthatarefusedcarbonringsthatcanbehormones(chemical
messengersinthebody)orstructuralunits(cholesterolisapartofthecell
membrane)
18.Beabletodrawandlabelthepartsofthephospholipidbilayer
Lipids: Structure
• Phospholipid—component of cell membranes
Polar
Head
Glycerol
Hydrophilic
Fatty Acid Tails
Hydrophobic
19.Knowthedifferenttestsonecanusetodetermineifthereisapresenceof
proteins,simplesugarsorcomplexsugars(LAB)
+forSimplesugars(likeglucose):benedict’ssolution(turnsfrompeacockblueto
orangeorbrickred)
+forComplexsugars(likestarch):Lugol’sIODINE(orange)turnsthesubstance
black
+forProteins(likemeat):Biuret’ssolutionturnsviolet
20. Give three examples of proteins composed of amino acids and describe the
function of each.
Keratin-structural support in nails
Muscle (actin and myosin) for movement
Collagen-maintains the elasticity of skin
Hemoglobin-a protein in red blood cells that carries oxygen to tissues
Dothesequestions:
Multiplechoicequestions#1-39justthenumberandletteranswer(do
correctionsafterwardsinadifferentcolourandexplainthecorrection)
ShortAnswerquestions:#43,44,46,47,49,51-54,55-57,59,60,62,63,68,
72,77,79,81(docorrectionsafterwardsinadifferentcolourandexplainthe
correction)
Note:#19,insulinisaproteinandthereforehasaminogroupswithN
Short Answer questions
43) The strong acid hydrogen chloride can be dissolved in water. The pH will decrease and cause
the solution to be more acidic due to the release of hydrogen ions.
44) Bond X is a hydrogen bond.
46) Functions: acts as a solvent by dissolving substances, acts as a lubricant by lubricating joints,
acts as a temperature regulator for body heat.
47) The electronegativity of the covalent bond causes the shared electron pair to spend more
time around the nucleus of the oxygen atom than that of the hydrogen atom in a water molecule.
This creates a slightly negative charge on the oxygen atom and slightly positive charges on the
hydrogen atoms resulting in an unequal sharing of electrons and a polar covalent bond.
49) Runners eat meals with large quantities of carbohydrates a few days before a marathon
because it provides quick fuel and short-term energy storage. The body will store the
carbohydrates needed for the race and on the day of the race, glycogen will be converted into
glucose so that glucose can be used to produce ATP during cellular respiration.
51) Dehydration synthesis is illustrated in the diagram. It shows the removal of a hydroxyl group
of one amino acid and the hydrogen atom of the second amino acid, the equivalent of water, to
allow the combining of the two into a dipeptide.
52) Bond X is a peptide bond.
53) A dipeptide and a water molecule will form as a result of this reaction.
54) 9 molecules of water will be produced if 10 amino acids are linked
55) Lactose is classified as a disaccharide that belongs to the carbohydrate family.
56) Water is required.
57) Hydrolysis is illustrated in the diagram.
59) a. The base sequences of specific sections of DNA contain a code that specifies the
sequence of amino acids in the proteins of the cell.
b. Nucleic acids are polymers of nucleotide monomers.
c. A monosaccharide only has one sugar molecule whereas a polysaccharide contains many
sugar molecules.
d. A polypeptide is made up of amino acids joined together by peptide bonds.
e. In the secondary structure of a protein, hydrogen bonding between the amino acids causes the
polypeptide to form an alpha helix or a beta pleated sheet.
f. The polarity in water molecules allows it stick together or cohesion to occur. Unequal sharing of
electrons in water.
60) a. A glycerol has three carbon atoms, each of which has a hydroxyl (-OH) group bound to it.
b. A triglyceride has three fatty acids attached to glycerol whereas a phospholipid has a
phosphate group that replaces one of the fatty acids.
c. A peptide bond forms between carboxyl group and the nitrogen of the amino group in a
dipeptide. A hydrogen bond forms between different amino acids in the polypeptide chain.
d. An unsaturated fatty acid has a double bond meaning it has one less hydrogen atom than a
saturated fatty acid.
62) The positive result of both the disaccharide maltose and the monosaccharide glucose means
there is a presence of sugar. It must have been positive because the monosaccharide glucose
makes up maltose when two combine.
63) When a mixture of phospholipids and water is shaken, the phospholipids spontaneously
assemble in vesicles surrounded by a lipid bilayer because the their polar heads are hydrophilic
and their non polar tails are hydrophobic.
68) This is a change in the primary structure of the polypeptide chain as this is where a certain
orientation is taken on. The hydrogen bonding between the altered sequence of amino acids will
change the shape causing the tertiary and quaternary to also be affected as these are later
stages in the protein organization where more bonding occurs.
72) Proteins are more structurally and functionally diverse than carbohydrates because the
variety in its R group allows for a uniqueness in each amino acid.
77)
CELLULOSE
STARCH
GLYCOGEN
Monomer
Glucose
Glucose
Glucose
Description of Structure
No side chains
Less side chains
More side branches
(chains of glucose) that
branch off from the main
chain than starch
Plant or Animal Cell
plant
plant
animal
Function
Structural support in plants Long term storage in
plants
Long term storage in
animals
Characteristic
DNA
RNA
PROTEIN
Polymer?
Yes
Yes
Yes
3-D Structure?
Yes
Yes
Yes
Contain nitrogen atoms?
Yes
Yes
Yes
Phosphorus atoms?
Yes
Yes
No
Hydrogen bonding?
Yes
No - YES
Yes
79)
81) Protein organization bonding:
a. primary – peptide bonds
b. secondary – hydrogen bonding
c. tertiary – covalent bonding, ionic bonding, H bonding and hydrophilic parts of proteins face
outwards
d. quaternary – bond between 2 or more polypeptides