MCAT Biology Practice Exam
2026/2027 Updated Verified
Questions and Solutions A+
Pass Guaranteed
1. The chemical reaction that breaks down all the major
macro-molecules
- ANS - Hydrolysis
2. What is the strongest type of INTER-molecular bonds?
- ANS - Hydrogen bonds are the strongest intermolecular
bonds....
3. diople-dipole bonds are weaker. . . Vander wall bonds are
the weakest.
4. Why is water a liquid at high temperatures?
- ANS - Hydrogen bonding bonds the water molocules
closer together.
5. What is an ampipathic molecule? give an Example.
- ANS - A molecule with both hydrophobic and
hydrophilic regions.
6. Example: PhoshpoLipid (Phospho=philic,lipid= phobic)
,7. What is a lipid?
- ANS - A lipid is a biological molecule with low solubility
in water.
8. Lipid means fat. Liposuction is fat removal.
9. Peptides are NOT lipids.
10. What are the 6 major groups of lipids?
- ANS - 1) fatty acids...
11. the next 3 have a 3 carbon back bone:
12. 2) Tri-glyceride
13. 3) Phospholipids
14. 4) Glycolipids
15. 5) Steroids
16. 6) Terpenes - A large class of organic compounds.
examples: smelly pine oils, beer hops aroma and vitamin
A.
17. What is the structure of a Tri-glyceride?
- ANS - triglicerides are esters. Composed from 3 carbon
glycerol backbone and 3 fatty acid chains dangling. Each
carbon chain is attached by an ester bond.
18. What happens if you add water to an ester group in a
Tri-glyceride? How is this reaction rate increased?
- ANS - Water cleaves the ester bond into an alcohol and a
, carboxylic/ fatty acid. LIPASES speed are the enzyme that
speed this reaction.
19. in terms of water solubility, What is important to
know about the longer the carbon chain in a Tri-glyceride
when broken down?
- ANS - longer carbon chains are less water soluble.
20. In longer chains the polar carboxylic acid are less
significant.
21. How soluble is a Shorter chain fatty acids?
- ANS - Shorter chain fatty acids are slightly water
soluble.
22. explain what is so special about Saturated Fatty
Acids........Also, explain the melting point.
- ANS - 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.
23. explain what is so special about Unsaturated Fatty
Acid.... Also, explain the melting point.
- ANS - Unsaturated fatty acids have at least one double
, bond. They are not saturated with Hydrogen. they have a
LOWER melting point.
24. At room temperatures unsaturated fatty acids may
be oily, like Healthy peanut butter.
25. explain the phospho-lipids structure. Where are
phoshpo lipids common?
- ANS - Phospholipids are also built on a 3 Carbon
backbone.
26. One of the carbon has a Phosphate PO4 group. the
other 2 carbons have carbon chains attached by a ester
bond.
27. This is the lollypop of the cell membrane. Esters
have 2 oxygens.
28. What regions are poplar nonpolar in a membrane?
- ANS - 1)the phosphates are Polar, water lovin, hydro
philic regions that face the outside.
29. 2) Nonpolar, hydro phobic carbon chain regions face
the inside.
30. Explain glycolipids structure.
- ANS - glycolipids have 3 carbon backbone with
31. 2 Carbon chains attached by an ester group.
32. THe third carbon has a carbohydrate
2026/2027 Updated Verified
Questions and Solutions A+
Pass Guaranteed
1. The chemical reaction that breaks down all the major
macro-molecules
- ANS - Hydrolysis
2. What is the strongest type of INTER-molecular bonds?
- ANS - Hydrogen bonds are the strongest intermolecular
bonds....
3. diople-dipole bonds are weaker. . . Vander wall bonds are
the weakest.
4. Why is water a liquid at high temperatures?
- ANS - Hydrogen bonding bonds the water molocules
closer together.
5. What is an ampipathic molecule? give an Example.
- ANS - A molecule with both hydrophobic and
hydrophilic regions.
6. Example: PhoshpoLipid (Phospho=philic,lipid= phobic)
,7. What is a lipid?
- ANS - A lipid is a biological molecule with low solubility
in water.
8. Lipid means fat. Liposuction is fat removal.
9. Peptides are NOT lipids.
10. What are the 6 major groups of lipids?
- ANS - 1) fatty acids...
11. the next 3 have a 3 carbon back bone:
12. 2) Tri-glyceride
13. 3) Phospholipids
14. 4) Glycolipids
15. 5) Steroids
16. 6) Terpenes - A large class of organic compounds.
examples: smelly pine oils, beer hops aroma and vitamin
A.
17. What is the structure of a Tri-glyceride?
- ANS - triglicerides are esters. Composed from 3 carbon
glycerol backbone and 3 fatty acid chains dangling. Each
carbon chain is attached by an ester bond.
18. What happens if you add water to an ester group in a
Tri-glyceride? How is this reaction rate increased?
- ANS - Water cleaves the ester bond into an alcohol and a
, carboxylic/ fatty acid. LIPASES speed are the enzyme that
speed this reaction.
19. in terms of water solubility, What is important to
know about the longer the carbon chain in a Tri-glyceride
when broken down?
- ANS - longer carbon chains are less water soluble.
20. In longer chains the polar carboxylic acid are less
significant.
21. How soluble is a Shorter chain fatty acids?
- ANS - Shorter chain fatty acids are slightly water
soluble.
22. explain what is so special about Saturated Fatty
Acids........Also, explain the melting point.
- ANS - 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.
23. explain what is so special about Unsaturated Fatty
Acid.... Also, explain the melting point.
- ANS - Unsaturated fatty acids have at least one double
, bond. They are not saturated with Hydrogen. they have a
LOWER melting point.
24. At room temperatures unsaturated fatty acids may
be oily, like Healthy peanut butter.
25. explain the phospho-lipids structure. Where are
phoshpo lipids common?
- ANS - Phospholipids are also built on a 3 Carbon
backbone.
26. One of the carbon has a Phosphate PO4 group. the
other 2 carbons have carbon chains attached by a ester
bond.
27. This is the lollypop of the cell membrane. Esters
have 2 oxygens.
28. What regions are poplar nonpolar in a membrane?
- ANS - 1)the phosphates are Polar, water lovin, hydro
philic regions that face the outside.
29. 2) Nonpolar, hydro phobic carbon chain regions face
the inside.
30. Explain glycolipids structure.
- ANS - glycolipids have 3 carbon backbone with
31. 2 Carbon chains attached by an ester group.
32. THe third carbon has a carbohydrate
