MCAT Biology Practice Questions and Answers Rated A
the chemical reaction that breaks down all the 3 fatty acid chains dangling. Each carbon chain is
major macro-molecules - ANSWER - attached by an ester bond.
Hydrolysis
What happens if you add water to an ester group
What is the strongest type of INTER-molecular in a Tri-glyceride? How is this reaction rate
bonds? - ANSWER -Hydrogen bonds are increased? - ANSWER -Water cleaves the
the strongest intermolecular bonds.... ester bond into an alcohol and a carboxylic/ fatty
diople-dipole bonds are weaker. . . Vander wall acid. LIPASES speed are the enzyme that speed
bonds are the weakest. this reaction.
Why is water a liquid at high temperatures? - in terms of water solubility, What is important to
ANSWER -Hydrogen bonding bonds the know about the longer the carbon chain in a Tri-
water molocules closer together. glyceride when broken down? - ANSWER -
longer carbon chains are less water soluble.
In longer chains the polar carboxylic acid are less
What is an ampipathic molecule? give an significant.
Example. - ANSWER -A molecule with both
hydrophobic and hydrophilic regions.
Example: PhoshpoLipid (Phospho=philic,lipid= How soluble is a Shorter chain fatty acids? -
phobic) ANSWER -Shorter chain fatty acids are
slightly water soluble.
What is a lipid? - ANSWER -A lipid is a
biological molecule with low solubility in water. explain what is so special about Saturated Fatty
Lipid means fat. Liposuction is fat removal. Acids........Also, explain the melting point. -
Peptides are NOT lipids. ANSWER -saturated fatty acids have only
single, alkane bonds along the carbon chain.
They have a straighter chain and have more van
What are the 6 major groups of lipids? - der wall forces, and therefor a higher melting
ANSWER -1) fatty acids... point.
the next 3 have a 3 carbon back bone:
2) Tri-glyceride
3) Phospholipids explain what is so special about Unsaturated
4) Glycolipids Fatty Acid.... Also, explain the melting point. -
5) Steroids ANSWER -Unsaturated fatty acids have at
6) Terpenes - A large class of organic least one double bond. They are not saturated
compounds. examples: smelly pine oils, beer with Hydrogen. they have a LOWER melting
hops aroma and vitamin A. point.
At room temperatures unsaturated fatty acids
may be oily, like Healthy peanut butter.
What is the structure of a Tri-glyceride? -
ANSWER -triglicerides are esters.
Composed from 3 carbon glycerol backbone and explain the phospho-lipids structure. Where are
phoshpo lipids common? - ANSWER -
, MCAT Biology Practice Questions and Answers Rated A
Phospholipids are also built on a 3 Carbon describe amino acid structure. - ANSWER -
backbone. Amino acids have 4 parts attached to the alpha
One of the carbon has a Phosphate PO4 group. carbon.
the other 2 carbons have carbon chains attached 1. the amino group, which is NH2
by a ester bond. 2. the R group, which is one of 20 choices
This is the lollypop of the cell membrane. Esters 3. the Carboxylic acid or C O O
have 2 oxygens. the last thing attached to the Carbon is the
Hydrogen.
What regions are poplar nonpolar in a
membrane? - ANSWER -1)the phosphates What are the basic amino acids? -
are Polar, water lovin, hydro philic regions that ANSWER -Hal
face the outside. Histidine
2) Nonpolar, hydro phobic carbon chain regions Arginine
face the inside. Lysine
Explain glycolipids structure. - ANSWER - What are the acidic amino acids? -
glycolipids have 3 carbon backbone with ANSWER -Aspartic acid and Glutamic acid
2 Carbon chains attached by an ester group.
THe third carbon has a carbohydrate
What are the nonpolar amino acids? -
ANSWER -Poor LTMG Is Venezuelan At
What do steroids look like? - ANSWER - Parties
Slightly amphipathic 4 ring structures 1) Phenylalanine
2) Leucine
3) Tryptophan
lipids are insoluble. So how do they move 4) Methionine
through the blood? - ANSWER -They are 5) Glycine
usually carried by lipoproteins, like HDL or LDL. 6) Isoleucine
7) Valine
8) Alanine
What are the major classes of lipoproteins? - 9) Proline
ANSWER -1) Chylomicrons which are the
largest
2) VLDLs these are low denstiy, but large. What is the primary structure of a protein? -
3) LDLs ANSWER -Sequence of amino acids and
4) HDLs. these high density lipids are the Location of disulfide bonds between cistine
smallest, and called good proteins. residues
What are proteins made up of? - What is the secondary structure of a protein? -
ANSWER -one or more chains of amino ANSWER -1) Twisting of the alpha helix
acids, perhaps in a crazy ass arrangement. 2) Beta sheets
, MCAT Biology Practice Questions and Answers Rated A
What is the tertiary structure of a protein? - ANSWER -1) Aldehyde
ANSWER -3D structure including bending 2) Has 4 chiral carbons
3) Fischer - R, L, R, R
4) 6 membered ring where one of the ring
What is the quaternary structure of a protein? - members is oxygen
ANSWER -Multiple proteins in formation 5) C1 - anomeric carbon
What are the five forces that create tertiary Where is glucose stored in alpha linkages? -
structure? - ANSWER -1) Covalent ANSWER -Animals (glycogen) and plants
2) Disulfide bonding between cysteine residues (starch)
(Bond itself creates tertiary structure)
3) H bonds
4) HPhob away from cytosol and Hphil Who stores glucose with beta linkages? -
interactions towards cytosol ANSWER -beta linkages are in Plant cell
5) Van Der Waals (dipoles, instantaneous walls. Cellulose.
dipoles)
What molecule is added to glycogen, starch, and
What levels of structure are disrupted during the cellulose to break off individual glucose
denaturation process? - ANSWER - molecules? - ANSWER -Water
Secondary - quaternary Hydrolysis reaction.
and enzymes like amylase speed it up.
What is the difference between a proteoglycan
and a glycoprotein? - ANSWER - What are the four macromolecules? -
Glycoproteins: ANSWER -Protein
1) Made of protein and carbohydrate Lipids
2) More stable than proteins Carbohydrates
3) Often used in IS to bridge the cellular Nucleic acids
membrane.
4) Ratio - have more proteins
What are the three parts of a nucleotide? -
Proteoglycans: ANSWER -Ribose sugar
1) Special class of glycoprotein Nitrogenous base
2) Contain extra carbohydrates PO4 group
3) Structure = protein with one or more
glycosaminoglycan chains.
4) Ratio - have more carbs What molecule breaks up nucleic acids into
nucleotides? - ANSWER -Water.
with the help of nucleases.
What is the empirical formula for any
carbohydrate? - ANSWER -CH2O
What are some other important nucleotides? -
ANSWER -FADH, NADH, ATP cyclic AMP
Describe the chemical structure of glucose -
, MCAT Biology Practice Questions and Answers Rated A
set of substrate at a time, the reaction rate
increases when we add substrate only as long as
What are minerals? - ANSWER -1) there are unoccupied enzyme molecules.
Inorganic elements that typically exist in the form Once we reach saturation, adding more substrate
of ions inside and outside of the cell. won't increase the reaction rate.
2) Function to: Enzyme is not used up!
a) Establish electrochemical gradients
b) Act as cofactors to enable protein function
c) Form matrix compounds in bone and etc What are the factors that affect enzymatic
reactions? - ANSWER -1) Optimal temp
(rate increases as temp incr until end is
What are enzymes? - ANSWER -Typically denatured)
a protein that Increase the rate of reaction by 2) Optimal pH
lowering activation energy.
but ribosomes are enzymes
How do cells regulate enzymes? -
ANSWER -1) Inhibition
What is activation energy? - ANSWER - 2) Production of inactive form, activate only when
energy needed to break the bonds of the needed
reactants creating the transition state, or the
species between the reactants or the products
What are the general types of enzyme inhibition?
- ANSWER -1) Feedback inhibition
T/F: enzyme is typically larger than the substrate 2) Chemical inhibition (poisons)
- ANSWER -True
What is feedback inhibition? - ANSWER -
Where does a substrate attach to an enzyme? - When the product of a reaction near the end of a
ANSWER -at the active site chain of reactions inhibits the function of an
enzyme in an earlier reaction of the chain.
What are the two hypotheses of enzyme and
substrate interactions? - ANSWER -1) Lock What are specific ways in which enzymes are
and Key Model inhibited (mechanism)? - ANSWER -1)
2) Induced Fit Model Competitive
2) Non-competitive
3) Irreversible
T/F: One enzyme is tailor made for one reaction.
- ANSWER -True: Enzyme specificity; gives
the cell more control in regulating chemical What is competitive inhibition? - ANSWER -
reactions 1) Compete for active site.
2) Can be overcome by increasing substrate
concentration.
What are saturation kinetics? - ANSWER -
Since a single enzyme molecule works on one
What is non-competitive inhibition? -
the chemical reaction that breaks down all the 3 fatty acid chains dangling. Each carbon chain is
major macro-molecules - ANSWER - attached by an ester bond.
Hydrolysis
What happens if you add water to an ester group
What is the strongest type of INTER-molecular in a Tri-glyceride? How is this reaction rate
bonds? - ANSWER -Hydrogen bonds are increased? - ANSWER -Water cleaves the
the strongest intermolecular bonds.... ester bond into an alcohol and a carboxylic/ fatty
diople-dipole bonds are weaker. . . Vander wall acid. LIPASES speed are the enzyme that speed
bonds are the weakest. this reaction.
Why is water a liquid at high temperatures? - in terms of water solubility, What is important to
ANSWER -Hydrogen bonding bonds the know about the longer the carbon chain in a Tri-
water molocules closer together. glyceride when broken down? - ANSWER -
longer carbon chains are less water soluble.
In longer chains the polar carboxylic acid are less
What is an ampipathic molecule? give an significant.
Example. - ANSWER -A molecule with both
hydrophobic and hydrophilic regions.
Example: PhoshpoLipid (Phospho=philic,lipid= How soluble is a Shorter chain fatty acids? -
phobic) ANSWER -Shorter chain fatty acids are
slightly water soluble.
What is a lipid? - ANSWER -A lipid is a
biological molecule with low solubility in water. explain what is so special about Saturated Fatty
Lipid means fat. Liposuction is fat removal. Acids........Also, explain the melting point. -
Peptides are NOT lipids. ANSWER -saturated fatty acids have only
single, alkane bonds along the carbon chain.
They have a straighter chain and have more van
What are the 6 major groups of lipids? - der wall forces, and therefor a higher melting
ANSWER -1) fatty acids... point.
the next 3 have a 3 carbon back bone:
2) Tri-glyceride
3) Phospholipids explain what is so special about Unsaturated
4) Glycolipids Fatty Acid.... Also, explain the melting point. -
5) Steroids ANSWER -Unsaturated fatty acids have at
6) Terpenes - A large class of organic least one double bond. They are not saturated
compounds. examples: smelly pine oils, beer with Hydrogen. they have a LOWER melting
hops aroma and vitamin A. point.
At room temperatures unsaturated fatty acids
may be oily, like Healthy peanut butter.
What is the structure of a Tri-glyceride? -
ANSWER -triglicerides are esters.
Composed from 3 carbon glycerol backbone and explain the phospho-lipids structure. Where are
phoshpo lipids common? - ANSWER -
, MCAT Biology Practice Questions and Answers Rated A
Phospholipids are also built on a 3 Carbon describe amino acid structure. - ANSWER -
backbone. Amino acids have 4 parts attached to the alpha
One of the carbon has a Phosphate PO4 group. carbon.
the other 2 carbons have carbon chains attached 1. the amino group, which is NH2
by a ester bond. 2. the R group, which is one of 20 choices
This is the lollypop of the cell membrane. Esters 3. the Carboxylic acid or C O O
have 2 oxygens. the last thing attached to the Carbon is the
Hydrogen.
What regions are poplar nonpolar in a
membrane? - ANSWER -1)the phosphates What are the basic amino acids? -
are Polar, water lovin, hydro philic regions that ANSWER -Hal
face the outside. Histidine
2) Nonpolar, hydro phobic carbon chain regions Arginine
face the inside. Lysine
Explain glycolipids structure. - ANSWER - What are the acidic amino acids? -
glycolipids have 3 carbon backbone with ANSWER -Aspartic acid and Glutamic acid
2 Carbon chains attached by an ester group.
THe third carbon has a carbohydrate
What are the nonpolar amino acids? -
ANSWER -Poor LTMG Is Venezuelan At
What do steroids look like? - ANSWER - Parties
Slightly amphipathic 4 ring structures 1) Phenylalanine
2) Leucine
3) Tryptophan
lipids are insoluble. So how do they move 4) Methionine
through the blood? - ANSWER -They are 5) Glycine
usually carried by lipoproteins, like HDL or LDL. 6) Isoleucine
7) Valine
8) Alanine
What are the major classes of lipoproteins? - 9) Proline
ANSWER -1) Chylomicrons which are the
largest
2) VLDLs these are low denstiy, but large. What is the primary structure of a protein? -
3) LDLs ANSWER -Sequence of amino acids and
4) HDLs. these high density lipids are the Location of disulfide bonds between cistine
smallest, and called good proteins. residues
What are proteins made up of? - What is the secondary structure of a protein? -
ANSWER -one or more chains of amino ANSWER -1) Twisting of the alpha helix
acids, perhaps in a crazy ass arrangement. 2) Beta sheets
, MCAT Biology Practice Questions and Answers Rated A
What is the tertiary structure of a protein? - ANSWER -1) Aldehyde
ANSWER -3D structure including bending 2) Has 4 chiral carbons
3) Fischer - R, L, R, R
4) 6 membered ring where one of the ring
What is the quaternary structure of a protein? - members is oxygen
ANSWER -Multiple proteins in formation 5) C1 - anomeric carbon
What are the five forces that create tertiary Where is glucose stored in alpha linkages? -
structure? - ANSWER -1) Covalent ANSWER -Animals (glycogen) and plants
2) Disulfide bonding between cysteine residues (starch)
(Bond itself creates tertiary structure)
3) H bonds
4) HPhob away from cytosol and Hphil Who stores glucose with beta linkages? -
interactions towards cytosol ANSWER -beta linkages are in Plant cell
5) Van Der Waals (dipoles, instantaneous walls. Cellulose.
dipoles)
What molecule is added to glycogen, starch, and
What levels of structure are disrupted during the cellulose to break off individual glucose
denaturation process? - ANSWER - molecules? - ANSWER -Water
Secondary - quaternary Hydrolysis reaction.
and enzymes like amylase speed it up.
What is the difference between a proteoglycan
and a glycoprotein? - ANSWER - What are the four macromolecules? -
Glycoproteins: ANSWER -Protein
1) Made of protein and carbohydrate Lipids
2) More stable than proteins Carbohydrates
3) Often used in IS to bridge the cellular Nucleic acids
membrane.
4) Ratio - have more proteins
What are the three parts of a nucleotide? -
Proteoglycans: ANSWER -Ribose sugar
1) Special class of glycoprotein Nitrogenous base
2) Contain extra carbohydrates PO4 group
3) Structure = protein with one or more
glycosaminoglycan chains.
4) Ratio - have more carbs What molecule breaks up nucleic acids into
nucleotides? - ANSWER -Water.
with the help of nucleases.
What is the empirical formula for any
carbohydrate? - ANSWER -CH2O
What are some other important nucleotides? -
ANSWER -FADH, NADH, ATP cyclic AMP
Describe the chemical structure of glucose -
, MCAT Biology Practice Questions and Answers Rated A
set of substrate at a time, the reaction rate
increases when we add substrate only as long as
What are minerals? - ANSWER -1) there are unoccupied enzyme molecules.
Inorganic elements that typically exist in the form Once we reach saturation, adding more substrate
of ions inside and outside of the cell. won't increase the reaction rate.
2) Function to: Enzyme is not used up!
a) Establish electrochemical gradients
b) Act as cofactors to enable protein function
c) Form matrix compounds in bone and etc What are the factors that affect enzymatic
reactions? - ANSWER -1) Optimal temp
(rate increases as temp incr until end is
What are enzymes? - ANSWER -Typically denatured)
a protein that Increase the rate of reaction by 2) Optimal pH
lowering activation energy.
but ribosomes are enzymes
How do cells regulate enzymes? -
ANSWER -1) Inhibition
What is activation energy? - ANSWER - 2) Production of inactive form, activate only when
energy needed to break the bonds of the needed
reactants creating the transition state, or the
species between the reactants or the products
What are the general types of enzyme inhibition?
- ANSWER -1) Feedback inhibition
T/F: enzyme is typically larger than the substrate 2) Chemical inhibition (poisons)
- ANSWER -True
What is feedback inhibition? - ANSWER -
Where does a substrate attach to an enzyme? - When the product of a reaction near the end of a
ANSWER -at the active site chain of reactions inhibits the function of an
enzyme in an earlier reaction of the chain.
What are the two hypotheses of enzyme and
substrate interactions? - ANSWER -1) Lock What are specific ways in which enzymes are
and Key Model inhibited (mechanism)? - ANSWER -1)
2) Induced Fit Model Competitive
2) Non-competitive
3) Irreversible
T/F: One enzyme is tailor made for one reaction.
- ANSWER -True: Enzyme specificity; gives
the cell more control in regulating chemical What is competitive inhibition? - ANSWER -
reactions 1) Compete for active site.
2) Can be overcome by increasing substrate
concentration.
What are saturation kinetics? - ANSWER -
Since a single enzyme molecule works on one
What is non-competitive inhibition? -
