BCH 351 EXAM 3 UPDATED ACTUAL QUESTIONS AND
CORRECT ANSWERS
Question:
1. what are the 9 biological functions of lipids?
Answer:
-storage of energy
-insulation from environment
-water repellant
-buoyancy control in marine mammals
-membrane structure
-cofactors for enzymes
-signaling molecules
-pigments
-antioxidants
Question:
2. what is lipid function in the storage of energy?
Answer:
-reduced compounds: lot of availabl energy
-hydrophobic nature: good packing
Question:
3. what is lipid function in insulation from the enviornment?
Answer:
-low thermal conductivity
-high heat capacity (can "absorb" heat)
-mechanical protection (can absorb shocks)
Question:
4. what is lipid function in water repellant?
Answer:
hydrophobic nature: keeps surface of the organism dry
-prevents excessive wetting (birds)
-prevents loss of water via evaporation
Question:
5. what is lipid function in buoyancy control in marine
mammals?
Answer:
increased density while diving deep helps sinking (just a hypothesis)
,Question:
6. what is lipid function in membrane structure?
Answer:
main structure of cell membranes
Question:
7. what is lipid function in cofactors for enzymes?
Answer:
-vitamin K: blood clot formation
-coenzyme Q: ATP synthesis in mitochondria
Question:
8. what is lipid function in signaling molecules?
Answer:
-paracrine hormones (act locally)
-steroid hormones (act body-wide)
-growth factors
-vitamins A and D (hormone precursors)
Question:
9. what is lipid function in pigments?
Answer:
color of tomatoes, carrots, pumpkins, some birds
Question:
10. what is lipid function in antioxidants?
Answer:
vitamin E
Question:
11. what do all fatty acids have ?
Answer:
-a carboxylate group at their head
-a long hydrocarbon tail
Question:
12. describe a carboxylate group
Answer:
-COO-
-pKa = 4.8
-hydrophilic
, Question:
13. describe a hydrocarbon tail
Answer:
-hydrophobic
-4 to 36 carbons, almost always an even number
-can be saturated or unsaturated
- C=C can be cis or trans
Question:
14. what is saturated ?
Answer:
No C=C
Question:
15. what is unsaturated?
Answer:
- 1 C=C is monounsaturated
- more than 1 C=C is polyunsaturated
Question:
16. what does the first number in fatty acid nomenclature tell
you?
Answer:
it tells you the number of carbons in the fatty acid
Question:
17. what does the second number in fatty acid nomenclature
tell you?
Answer:
it tells you the number of double bonds
CORRECT ANSWERS
Question:
1. what are the 9 biological functions of lipids?
Answer:
-storage of energy
-insulation from environment
-water repellant
-buoyancy control in marine mammals
-membrane structure
-cofactors for enzymes
-signaling molecules
-pigments
-antioxidants
Question:
2. what is lipid function in the storage of energy?
Answer:
-reduced compounds: lot of availabl energy
-hydrophobic nature: good packing
Question:
3. what is lipid function in insulation from the enviornment?
Answer:
-low thermal conductivity
-high heat capacity (can "absorb" heat)
-mechanical protection (can absorb shocks)
Question:
4. what is lipid function in water repellant?
Answer:
hydrophobic nature: keeps surface of the organism dry
-prevents excessive wetting (birds)
-prevents loss of water via evaporation
Question:
5. what is lipid function in buoyancy control in marine
mammals?
Answer:
increased density while diving deep helps sinking (just a hypothesis)
,Question:
6. what is lipid function in membrane structure?
Answer:
main structure of cell membranes
Question:
7. what is lipid function in cofactors for enzymes?
Answer:
-vitamin K: blood clot formation
-coenzyme Q: ATP synthesis in mitochondria
Question:
8. what is lipid function in signaling molecules?
Answer:
-paracrine hormones (act locally)
-steroid hormones (act body-wide)
-growth factors
-vitamins A and D (hormone precursors)
Question:
9. what is lipid function in pigments?
Answer:
color of tomatoes, carrots, pumpkins, some birds
Question:
10. what is lipid function in antioxidants?
Answer:
vitamin E
Question:
11. what do all fatty acids have ?
Answer:
-a carboxylate group at their head
-a long hydrocarbon tail
Question:
12. describe a carboxylate group
Answer:
-COO-
-pKa = 4.8
-hydrophilic
, Question:
13. describe a hydrocarbon tail
Answer:
-hydrophobic
-4 to 36 carbons, almost always an even number
-can be saturated or unsaturated
- C=C can be cis or trans
Question:
14. what is saturated ?
Answer:
No C=C
Question:
15. what is unsaturated?
Answer:
- 1 C=C is monounsaturated
- more than 1 C=C is polyunsaturated
Question:
16. what does the first number in fatty acid nomenclature tell
you?
Answer:
it tells you the number of carbons in the fatty acid
Question:
17. what does the second number in fatty acid nomenclature
tell you?
Answer:
it tells you the number of double bonds