MCAT Biology Questions (Correct Answers)
The chemical reaction that breaks down all the major macro-moleculesCorrect
AnswersHydrolysis
What is the strongest type of INTER-molecular bonds?Correct AnswersHydrogen bonds
are the strongest intermolecular bonds....
diople-dipole bonds are weaker. . . Vander wall bonds are the weakest.
Why is water a liquid at high temperatures?Correct AnswersHydrogen bonding bonds
the water molocules closer together.
What is an ampipathic molecule? give an Example.Correct AnswersA molecule with
both hydrophobic and hydrophilic regions.
Example: PhoshpoLipid (Phospho=philic,lipid= phobic)
What is a lipid?Correct AnswersA lipid is a biological molecule with low solubility in
water.
Lipid means fat. Liposuction is fat removal.
Peptides are NOT lipids.
What are the 6 major groups of lipids?Correct Answers1) fatty acids...
the next 3 have a 3 carbon back bone:
2) Tri-glyceride
3) Phospholipids
4) Glycolipids
5) Steroids
6) Terpenes - A large class of organic compounds. examples: smelly pine oils, beer
hops aroma and vitamin A.
What is the structure of a Tri-glyceride?Correct Answerstriglicerides are esters.
Composed from 3 carbon glycerol backbone and 3 fatty acid chains dangling. Each
carbon chain is attached by an ester bond.
What happens if you add water to an ester group in a Tri-glyceride? How is this reaction
rate increased?Correct AnswersWater cleaves the ester bond into an alcohol and a
carboxylic/ fatty acid. LIPASES speed are the enzyme that speed this reaction.
in terms of water solubility, What is important to know about the longer the carbon chain
in a Tri-glyceride when broken down?Correct Answerslonger carbon chains are less
water soluble.
In longer chains the polar carboxylic acid are less significant.
How soluble is a Shorter chain fatty acids?Correct AnswersShorter chain fatty acids are
slightly water soluble.
explain what is so special about Saturated Fatty Acids........Also, explain the melting
point.Correct Answerssaturated fatty acids have only single, alkane bonds along the
carbon chain. They have a straighter chain and have more van der wall forces, and
therefor a higher melting point.
explain what is so special about Unsaturated Fatty Acid.... Also, explain the melting
point.Correct AnswersUnsaturated fatty acids have at least one double bond. They are
not saturated with Hydrogen. they have a LOWER melting point.
At room temperatures unsaturated fatty acids may be oily, like Healthy peanut butter.
explain the phospho-lipids structure. Where are phoshpo lipids common?Correct
AnswersPhospholipids are also built on a 3 Carbon backbone.
,One of the carbon has a Phosphate PO4 group. the other 2 carbons have carbon
chains attached by a ester bond.
This is the lollypop of the cell membrane. Esters have 2 oxygens.
What regions are poplar nonpolar in a membrane?Correct Answers1)the phosphates
are Polar, water lovin, hydro philic regions that face the outside.
2) Nonpolar, hydro phobic carbon chain regions face the inside.
Explain glycolipids structure.Correct Answersglycolipids have 3 carbon backbone with
2 Carbon chains attached by an ester group.
THe third carbon has a carbohydrate
What do steroids look like?Correct AnswersSlightly amphipathic 4 ring structures
lipids are insoluble. So how do they move through the blood?Correct AnswersThey are
usually carried by lipoproteins, like HDL or LDL.
What are the major classes of lipoproteins?Correct Answers1) Chylomicrons which are
the largest
2) VLDLs these are low denstiy, but large.
3) LDLs
4) HDLs. these high density lipids are the smallest, and called good proteins.
What are proteins made up of?Correct Answersone or more chains of amino acids,
perhaps in a crazy ass arrangement.
describe amino acid structure.Correct AnswersAmino acids have 4 parts attached to the
alpha carbon.
1. the amino group, which is NH2
2. the R group, which is one of 20 choices
3. the Carboxylic acid or C O O
the last thing attached to the Carbon is the Hydrogen.
What are the basic amino acids?Correct AnswersHal
Histidine
Arginine
Lysine
What are the acidic amino acids?Correct AnswersAspartic acid and Glutamic acid
What are the nonpolar amino acids?Correct AnswersPoor LTMG Is Venezuelan At
Parties
1) Phenylalanine
2) Leucine
3) Tryptophan
4) Methionine
5) Glycine
6) Isoleucine
7) Valine
8) Alanine
9) Proline
What is the primary structure of a protein?Correct AnswersSequence of amino acids
and
Location of disulfide bonds between cistine residues
What is the secondary structure of a protein?Correct Answers1) Twisting of the alpha
helix
, 2) Beta sheets
What is the tertiary structure of a protein?Correct Answers3D structure including
bending
What is the quaternary structure of a protein?Correct AnswersMultiple proteins in
formation
What are the five forces that create tertiary structure?Correct Answers1) Covalent
2) Disulfide bonding between cysteine residues (Bond itself creates tertiary structure)
3) H bonds
4) HPhob away from cytosol and Hphil interactions towards cytosol
5) Van Der Waals (dipoles, instantaneous dipoles)
What levels of structure are disrupted during the denaturation process?Correct
AnswersSecondary - quaternary
What is the difference between a proteoglycan and a glycoprotein?Correct
AnswersGlycoproteins:
1) Made of protein and carbohydrate
2) More stable than proteins
3) Often used in IS to bridge the cellular membrane.
4) Ratio - have more proteins
Proteoglycans:
1) Special class of glycoprotein
2) Contain extra carbohydrates
3) Structure = protein with one or more glycosaminoglycan chains.
4) Ratio - have more carbs
What is the empirical formula for any carbohydrate?Correct AnswersCH2O
Describe the chemical structure of glucoseCorrect Answers1) Aldehyde
2) Has 4 chiral carbons
3) Fischer - R, L, R, R
4) 6 membered ring where one of the ring members is oxygen
5) C1 - anomeric carbon
Where is glucose stored in alpha linkages?Correct AnswersAnimals (glycogen) and
plants (starch)
Who stores glucose with beta linkages?Correct Answersbeta linkages are in Plant cell
walls. Cellulose.
What molecule is added to glycogen, starch, and cellulose to break off individual
glucose molecules?Correct AnswersWater
Hydrolysis reaction.
and enzymes like amylase speed it up.
What are the four macromolecules?Correct AnswersProtein
Lipids
Carbohydrates
Nucleic acids
What are the three parts of a nucleotide?Correct AnswersRibose sugar
Nitrogenous base
PO4 group
What molecule breaks up nucleic acids into nucleotides?Correct AnswersWater.
The chemical reaction that breaks down all the major macro-moleculesCorrect
AnswersHydrolysis
What is the strongest type of INTER-molecular bonds?Correct AnswersHydrogen bonds
are the strongest intermolecular bonds....
diople-dipole bonds are weaker. . . Vander wall bonds are the weakest.
Why is water a liquid at high temperatures?Correct AnswersHydrogen bonding bonds
the water molocules closer together.
What is an ampipathic molecule? give an Example.Correct AnswersA molecule with
both hydrophobic and hydrophilic regions.
Example: PhoshpoLipid (Phospho=philic,lipid= phobic)
What is a lipid?Correct AnswersA lipid is a biological molecule with low solubility in
water.
Lipid means fat. Liposuction is fat removal.
Peptides are NOT lipids.
What are the 6 major groups of lipids?Correct Answers1) fatty acids...
the next 3 have a 3 carbon back bone:
2) Tri-glyceride
3) Phospholipids
4) Glycolipids
5) Steroids
6) Terpenes - A large class of organic compounds. examples: smelly pine oils, beer
hops aroma and vitamin A.
What is the structure of a Tri-glyceride?Correct Answerstriglicerides are esters.
Composed from 3 carbon glycerol backbone and 3 fatty acid chains dangling. Each
carbon chain is attached by an ester bond.
What happens if you add water to an ester group in a Tri-glyceride? How is this reaction
rate increased?Correct AnswersWater cleaves the ester bond into an alcohol and a
carboxylic/ fatty acid. LIPASES speed are the enzyme that speed this reaction.
in terms of water solubility, What is important to know about the longer the carbon chain
in a Tri-glyceride when broken down?Correct Answerslonger carbon chains are less
water soluble.
In longer chains the polar carboxylic acid are less significant.
How soluble is a Shorter chain fatty acids?Correct AnswersShorter chain fatty acids are
slightly water soluble.
explain what is so special about Saturated Fatty Acids........Also, explain the melting
point.Correct Answerssaturated fatty acids have only single, alkane bonds along the
carbon chain. They have a straighter chain and have more van der wall forces, and
therefor a higher melting point.
explain what is so special about Unsaturated Fatty Acid.... Also, explain the melting
point.Correct AnswersUnsaturated fatty acids have at least one double bond. They are
not saturated with Hydrogen. they have a LOWER melting point.
At room temperatures unsaturated fatty acids may be oily, like Healthy peanut butter.
explain the phospho-lipids structure. Where are phoshpo lipids common?Correct
AnswersPhospholipids are also built on a 3 Carbon backbone.
,One of the carbon has a Phosphate PO4 group. the other 2 carbons have carbon
chains attached by a ester bond.
This is the lollypop of the cell membrane. Esters have 2 oxygens.
What regions are poplar nonpolar in a membrane?Correct Answers1)the phosphates
are Polar, water lovin, hydro philic regions that face the outside.
2) Nonpolar, hydro phobic carbon chain regions face the inside.
Explain glycolipids structure.Correct Answersglycolipids have 3 carbon backbone with
2 Carbon chains attached by an ester group.
THe third carbon has a carbohydrate
What do steroids look like?Correct AnswersSlightly amphipathic 4 ring structures
lipids are insoluble. So how do they move through the blood?Correct AnswersThey are
usually carried by lipoproteins, like HDL or LDL.
What are the major classes of lipoproteins?Correct Answers1) Chylomicrons which are
the largest
2) VLDLs these are low denstiy, but large.
3) LDLs
4) HDLs. these high density lipids are the smallest, and called good proteins.
What are proteins made up of?Correct Answersone or more chains of amino acids,
perhaps in a crazy ass arrangement.
describe amino acid structure.Correct AnswersAmino acids have 4 parts attached to the
alpha carbon.
1. the amino group, which is NH2
2. the R group, which is one of 20 choices
3. the Carboxylic acid or C O O
the last thing attached to the Carbon is the Hydrogen.
What are the basic amino acids?Correct AnswersHal
Histidine
Arginine
Lysine
What are the acidic amino acids?Correct AnswersAspartic acid and Glutamic acid
What are the nonpolar amino acids?Correct AnswersPoor LTMG Is Venezuelan At
Parties
1) Phenylalanine
2) Leucine
3) Tryptophan
4) Methionine
5) Glycine
6) Isoleucine
7) Valine
8) Alanine
9) Proline
What is the primary structure of a protein?Correct AnswersSequence of amino acids
and
Location of disulfide bonds between cistine residues
What is the secondary structure of a protein?Correct Answers1) Twisting of the alpha
helix
, 2) Beta sheets
What is the tertiary structure of a protein?Correct Answers3D structure including
bending
What is the quaternary structure of a protein?Correct AnswersMultiple proteins in
formation
What are the five forces that create tertiary structure?Correct Answers1) Covalent
2) Disulfide bonding between cysteine residues (Bond itself creates tertiary structure)
3) H bonds
4) HPhob away from cytosol and Hphil interactions towards cytosol
5) Van Der Waals (dipoles, instantaneous dipoles)
What levels of structure are disrupted during the denaturation process?Correct
AnswersSecondary - quaternary
What is the difference between a proteoglycan and a glycoprotein?Correct
AnswersGlycoproteins:
1) Made of protein and carbohydrate
2) More stable than proteins
3) Often used in IS to bridge the cellular membrane.
4) Ratio - have more proteins
Proteoglycans:
1) Special class of glycoprotein
2) Contain extra carbohydrates
3) Structure = protein with one or more glycosaminoglycan chains.
4) Ratio - have more carbs
What is the empirical formula for any carbohydrate?Correct AnswersCH2O
Describe the chemical structure of glucoseCorrect Answers1) Aldehyde
2) Has 4 chiral carbons
3) Fischer - R, L, R, R
4) 6 membered ring where one of the ring members is oxygen
5) C1 - anomeric carbon
Where is glucose stored in alpha linkages?Correct AnswersAnimals (glycogen) and
plants (starch)
Who stores glucose with beta linkages?Correct Answersbeta linkages are in Plant cell
walls. Cellulose.
What molecule is added to glycogen, starch, and cellulose to break off individual
glucose molecules?Correct AnswersWater
Hydrolysis reaction.
and enzymes like amylase speed it up.
What are the four macromolecules?Correct AnswersProtein
Lipids
Carbohydrates
Nucleic acids
What are the three parts of a nucleotide?Correct AnswersRibose sugar
Nitrogenous base
PO4 group
What molecule breaks up nucleic acids into nucleotides?Correct AnswersWater.
