MCAT BIOLOGY PRACTICE QUESTIONS WITH FULLY
SOLVED & UPDATED ANSWERS.
the chemical reaction that breaks down all the major macro-molecules -- Correct
_ _ _ _ _ _ _ _ _ _ _ _
Answer ✔✔ Hydrolysis _ _
What is the strongest type of INTER-molecular bonds? -- Correct Answer ✔✔
_ _ _ _ _ _ _ _ _ _ _ _
Hydrogen bonds are the strongest intermolecular bonds....
_ _ _ _ _ _
dipole-dipole bonds are weaker. . . Vander wall bonds are the weakest.
_ _ _ _ _ _ _ _ _ _ _
Why is water a liquid at high temperatures? -- Correct Answer ✔✔ Hydrogen bonding
_ _ _ _ _ _ _ _ _ _ _ _ _
bonds the water molecules closer together.
_ _ _ _ _ _
What is an amphipathic molecule? give an Example. -- Correct Answer ✔✔ A molecule
_ _ _ _ _ _ _ _ _ _ _ _ _
_with both hydrophobic and hydrophilic regions.
_ _ _ _ _
Example: Phospholipid (Phospho=philic,lipid= phobic)
_ _ _
What is a lipid? -- Correct Answer ✔✔ A 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 Answer ✔✔ 1) 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 Answer ✔✔ triglycerides 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 Answer ✔✔ Water 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 Answer ✔✔ longer 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 Answer ✔✔ Shorter chain fatty
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
acids are slightly water soluble.
_ _ _ _
explain what is so special about Saturated Fatty Acids........Also, explain the melting
_ _ _ _ _ _ _ _ _ _ _ _
point. -- Correct Answer ✔✔ saturated fatty acids have only single, alkane bonds along
_ _ _ _ _ _ _ _ _ _ _ _ _
_the carbon chain. They have a straighter chain and have more van der wall forces, and
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
therefore a higher melting point. _ _ _ _
explain what is so special about Unsaturated Fatty Acid.... Also, explain the melting
_ _ _ _ _ _ _ _ _ _ _ _ _
point. -- Correct Answer ✔✔ Unsaturated 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
_ _ _ _ _ _ _ _ _ _ _
Answer ✔✔ Phospholipids 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 Answer ✔✔ 1)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 Answer ✔✔ glycolipids 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 Answer ✔✔ Slightly amphipathic 4 ring
_ _ _ _ _ _ _ _ _ _ _ _ _
structures
lipids are insoluble. So how do they move through the blood? -- Correct Answer ✔✔
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
They are usually carried by lipoproteins, like HDL or LDL.
_ _ _ _ _ _ _ _ _
What are the major classes of lipoproteins? -- Correct Answer ✔✔ 1) Chylomicrons
_ _ _ _ _ _ _ _ _ _ _ _ _
which are the largest _ _ _ _
2) VLDLs these are low density, but large.
_ _ _ _ _ _ _
3) LDLs
_
4) HDLs. these high density lipids are the smallest, and called good proteins.
_ _ _ _ _ _ _ _ _ _ _ _
What are proteins made up of? -- Correct Answer ✔✔ one or more chains of amino
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
acids, perhaps in a crazy ass arrangement.
_ _ _ _ _ _
describe amino acid structure. -- Correct Answer ✔✔ Amino 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 Answer ✔✔ Hal
_ _ _ _ _ _ _ _ _ _
Histidine
Arginine
Lysine
, What are the acidic amino acids? -- Correct Answer ✔✔ Aspartic acid and Glutamic
_ _ _ _ _ _ _ _ _ _ _ _ _ _
acid
What are the nonpolar amino acids? -- Correct Answer ✔✔ Poor 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 Answer ✔✔ Sequence of amino
_ _ _ _ _ _ _ _ _ _ _ _ _ _
_acids and _ _
Location of disulfide bonds between cistine residues
_ _ _ _ _ _
What is the secondary structure of a protein? -- Correct Answer ✔✔ 1) Twisting of
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
the alpha helix
_ _
2) Beta sheets
_ _
What is the tertiary structure of a protein? -- Correct Answer ✔✔ 3D structure
_ _ _ _ _ _ _ _ _ _ _ _ _ _
including bending _
What is the quaternary structure of a protein? -- Correct Answer ✔✔ Multiple
_ _ _ _ _ _ _ _ _ _ _ _ _
proteins in formation _ _
What are the five forces that create tertiary structure? -- Correct Answer ✔✔ 1)
_ _ _ _ _ _ _ _ _ _ _ _ _ _
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)
_ _ _ _ _ _
SOLVED & UPDATED ANSWERS.
the chemical reaction that breaks down all the major macro-molecules -- Correct
_ _ _ _ _ _ _ _ _ _ _ _
Answer ✔✔ Hydrolysis _ _
What is the strongest type of INTER-molecular bonds? -- Correct Answer ✔✔
_ _ _ _ _ _ _ _ _ _ _ _
Hydrogen bonds are the strongest intermolecular bonds....
_ _ _ _ _ _
dipole-dipole bonds are weaker. . . Vander wall bonds are the weakest.
_ _ _ _ _ _ _ _ _ _ _
Why is water a liquid at high temperatures? -- Correct Answer ✔✔ Hydrogen bonding
_ _ _ _ _ _ _ _ _ _ _ _ _
bonds the water molecules closer together.
_ _ _ _ _ _
What is an amphipathic molecule? give an Example. -- Correct Answer ✔✔ A molecule
_ _ _ _ _ _ _ _ _ _ _ _ _
_with both hydrophobic and hydrophilic regions.
_ _ _ _ _
Example: Phospholipid (Phospho=philic,lipid= phobic)
_ _ _
What is a lipid? -- Correct Answer ✔✔ A 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 Answer ✔✔ 1) 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 Answer ✔✔ triglycerides 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 Answer ✔✔ Water 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 Answer ✔✔ longer 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 Answer ✔✔ Shorter chain fatty
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
acids are slightly water soluble.
_ _ _ _
explain what is so special about Saturated Fatty Acids........Also, explain the melting
_ _ _ _ _ _ _ _ _ _ _ _
point. -- Correct Answer ✔✔ saturated fatty acids have only single, alkane bonds along
_ _ _ _ _ _ _ _ _ _ _ _ _
_the carbon chain. They have a straighter chain and have more van der wall forces, and
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
therefore a higher melting point. _ _ _ _
explain what is so special about Unsaturated Fatty Acid.... Also, explain the melting
_ _ _ _ _ _ _ _ _ _ _ _ _
point. -- Correct Answer ✔✔ Unsaturated 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
_ _ _ _ _ _ _ _ _ _ _
Answer ✔✔ Phospholipids 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 Answer ✔✔ 1)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 Answer ✔✔ glycolipids 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 Answer ✔✔ Slightly amphipathic 4 ring
_ _ _ _ _ _ _ _ _ _ _ _ _
structures
lipids are insoluble. So how do they move through the blood? -- Correct Answer ✔✔
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
They are usually carried by lipoproteins, like HDL or LDL.
_ _ _ _ _ _ _ _ _
What are the major classes of lipoproteins? -- Correct Answer ✔✔ 1) Chylomicrons
_ _ _ _ _ _ _ _ _ _ _ _ _
which are the largest _ _ _ _
2) VLDLs these are low density, but large.
_ _ _ _ _ _ _
3) LDLs
_
4) HDLs. these high density lipids are the smallest, and called good proteins.
_ _ _ _ _ _ _ _ _ _ _ _
What are proteins made up of? -- Correct Answer ✔✔ one or more chains of amino
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
acids, perhaps in a crazy ass arrangement.
_ _ _ _ _ _
describe amino acid structure. -- Correct Answer ✔✔ Amino 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 Answer ✔✔ Hal
_ _ _ _ _ _ _ _ _ _
Histidine
Arginine
Lysine
, What are the acidic amino acids? -- Correct Answer ✔✔ Aspartic acid and Glutamic
_ _ _ _ _ _ _ _ _ _ _ _ _ _
acid
What are the nonpolar amino acids? -- Correct Answer ✔✔ Poor 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 Answer ✔✔ Sequence of amino
_ _ _ _ _ _ _ _ _ _ _ _ _ _
_acids and _ _
Location of disulfide bonds between cistine residues
_ _ _ _ _ _
What is the secondary structure of a protein? -- Correct Answer ✔✔ 1) Twisting of
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
the alpha helix
_ _
2) Beta sheets
_ _
What is the tertiary structure of a protein? -- Correct Answer ✔✔ 3D structure
_ _ _ _ _ _ _ _ _ _ _ _ _ _
including bending _
What is the quaternary structure of a protein? -- Correct Answer ✔✔ Multiple
_ _ _ _ _ _ _ _ _ _ _ _ _
proteins in formation _ _
What are the five forces that create tertiary structure? -- Correct Answer ✔✔ 1)
_ _ _ _ _ _ _ _ _ _ _ _ _ _
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)
_ _ _ _ _ _
