MCAT Biology Practice Questions
and Answers 100% Correct
the chemical reaction that breaks down all the major macro-molecules - ANSWER -
Hydrolysis
What is the strongest type of INTER-molecular bonds? - ANSWER - Hydrogen 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? - ANSWER - Hydrogen bonding bonds
the water molocules closer together.
What is an ampipathic molecule? give an Example. - ANSWER - A molecule with
both hydrophobic and hydrophilic regions.
Example: PhoshpoLipid (Phospho=philic,lipid= phobic)
What is a lipid? - 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? - 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? - ANSWER - triglicerides 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? - ANSWER - Water cleaves the ester bond into an alcohol
and a carboxylic/ fatty acid. LIPASES speed are the enzyme that speed this reaction.
What do steroids look like? - ANSWER - Slightly amphipathic 4 ring structures
lipids are insoluble. So how do they move through the blood? - ANSWER - They are
usually carried by lipoproteins, like HDL or LDL.
What are the major classes of lipoproteins? - ANSWER - 1) 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.
in terms of water solubility, What is important to know about the longer the carbon
chain in a Tri-glyceride when broken down? - 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? - ANSWER - Shorter chain fatty acids are
slightly water soluble.
explain what is so special about Saturated Fatty Acids........Also, explain the melting
point. - 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
therefor a higher melting point.
explain what is so special about Unsaturated Fatty Acid.... Also, explain the melting
point. - 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? - 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? - 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. - ANSWER - glycolipids have 3 carbon backbone with
2 Carbon chains attached by an ester group.
THe third carbon has a carbohydrate
What are proteins made up of? - ANSWER - one or more chains of amino acids,
perhaps in a crazy ass arrangement.
describe amino acid structure. - 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? - ANSWER - Hal
Histidine
Arginine
Lysine
, What are the acidic amino acids? - ANSWER - Aspartic acid and Glutamic acid
What are the nonpolar amino acids? - 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
Where is glucose stored in alpha linkages? - ANSWER - Animals (glycogen) and
plants (starch)
Who stores glucose with beta linkages? - ANSWER - beta linkages are in Plant cell
walls. Cellulose.
What molecule is added to glycogen, starch, and cellulose to break off individual
glucose molecules? - ANSWER - Water
Hydrolysis reaction.
and enzymes like amylase speed it up.
What is the primary structure of a protein? - ANSWER - Sequence of amino acids
and
Location of disulfide bonds between cistine residues
What is the secondary structure of a protein? - ANSWER - 1) Twisting of the alpha
helix
2) Beta sheets
and Answers 100% Correct
the chemical reaction that breaks down all the major macro-molecules - ANSWER -
Hydrolysis
What is the strongest type of INTER-molecular bonds? - ANSWER - Hydrogen 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? - ANSWER - Hydrogen bonding bonds
the water molocules closer together.
What is an ampipathic molecule? give an Example. - ANSWER - A molecule with
both hydrophobic and hydrophilic regions.
Example: PhoshpoLipid (Phospho=philic,lipid= phobic)
What is a lipid? - 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? - 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? - ANSWER - triglicerides 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? - ANSWER - Water cleaves the ester bond into an alcohol
and a carboxylic/ fatty acid. LIPASES speed are the enzyme that speed this reaction.
What do steroids look like? - ANSWER - Slightly amphipathic 4 ring structures
lipids are insoluble. So how do they move through the blood? - ANSWER - They are
usually carried by lipoproteins, like HDL or LDL.
What are the major classes of lipoproteins? - ANSWER - 1) 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.
in terms of water solubility, What is important to know about the longer the carbon
chain in a Tri-glyceride when broken down? - 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? - ANSWER - Shorter chain fatty acids are
slightly water soluble.
explain what is so special about Saturated Fatty Acids........Also, explain the melting
point. - 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
therefor a higher melting point.
explain what is so special about Unsaturated Fatty Acid.... Also, explain the melting
point. - 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? - 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? - 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. - ANSWER - glycolipids have 3 carbon backbone with
2 Carbon chains attached by an ester group.
THe third carbon has a carbohydrate
What are proteins made up of? - ANSWER - one or more chains of amino acids,
perhaps in a crazy ass arrangement.
describe amino acid structure. - 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? - ANSWER - Hal
Histidine
Arginine
Lysine
, What are the acidic amino acids? - ANSWER - Aspartic acid and Glutamic acid
What are the nonpolar amino acids? - 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
Where is glucose stored in alpha linkages? - ANSWER - Animals (glycogen) and
plants (starch)
Who stores glucose with beta linkages? - ANSWER - beta linkages are in Plant cell
walls. Cellulose.
What molecule is added to glycogen, starch, and cellulose to break off individual
glucose molecules? - ANSWER - Water
Hydrolysis reaction.
and enzymes like amylase speed it up.
What is the primary structure of a protein? - ANSWER - Sequence of amino acids
and
Location of disulfide bonds between cistine residues
What is the secondary structure of a protein? - ANSWER - 1) Twisting of the alpha
helix
2) Beta sheets
