Download Is water a polar or nonpolar molecule

Coenzymes and Cofactors
Indicate in the blank to the left of each reaction what cofactor or coenzyme the enzyme that catalyzes the
reaction may use for catalysis. Is there a vitamin required for synthesis of the coenzyme?
1. __________________
2. ___________________
3. ___________________
4. ___________________
5. ___________________
Vitamins
Sodium warfarin, which has a chemical structure similar to a vitamin we studied, is the active ingredient in rat poison.
Surprisingly, this drug is also given in small amounts to human patients who have recently had a problem with blood
clotting. Name the vitamin warfarin is similar to and postulate how this drug kills rats and why it might be given to a
human patient.
Ingestion of large doses of vitamins is usually not harmful, however some vitamins can be toxic in high doses. One of these is
vitamin A. From your knowledge of the physical properties of biomolecules, describe why vitamin A might be more toxic
than many other vitamins, such as vitamin C or the B vitamins.
Carbohydrates
What is the generic molecular formula for carbohydrates?
Draw the chemical structure of a ketohexose
Draw the chemical structure of an aldopentose
1. A dissacharide of glucose and fructose commonly known as
a. sucrose
b. chitin
c. glucose
d. ribose
2. A storage polysaccharide of plants is
a. starch
b. chitin
c. amylopectin
d. glycogen
3. A polysaccharide found in the exoskeleton of arthropods is
a. starch
b. chitin
c. amylopectin
d. glycogen
4. An unbranched polymer of glucose with -(1-4) linkages is
a. amylose
b. chitin
c. amylopectin
d. glycogen
5. Which of the following best describes glycogen?
a. A polymer of glucose with -(1-4) linkages and -(1-6) branches approximately every 10 sugars
b. A polymer of glucose with -(1-4) linkages and -(1-6) branches approximately every 25 sugars
c. A disaccharide containing glucose and fructose connected by a glycosidic bond
d. A 5-carbon aldohexose
6. Starch and glycogen are both polymers of:
a. -D-glucose
b. -D-glucose
c. glucose 1-phosphate
d. sucrose
7. Which of the following is a heteropolysaccharide?
a. glycogen
b. hyaluronate
c. starch
d. chitin
8. Which of the following amino acid residues is not a point of oligosaccharide attachment in glycoproteins?
a. Thr
b. Gly
c. Ser
d. Asn
Carbohydrates
Cellulose and starch are both polymers of glucose, yet most mammals can use starch, but not cellulose, as a source of fuel. Explain
why this is the case. Ruminents have successfully overcome this limitation and subsist on a diet of grasses. How have they
accomplished this feat?
A popular non-prescription preventative treatment for arthritis is the ingestion of dietary supplements containing glucosamine.
Anecdotal evidence in humans and previous date from veterinary studies have shown that these treatments offer relief, and some
protection from, arthritic joint pain. Explain why these supplements might benefit arthritis patients.
Lipids
1. Structural lipids in membranes
Which of the following statements concerning fatty acids is correct?
A) One is the precursor of prostaglandins.
B) Phosphatidic acid is a common one.
C) They all contain one or more double bonds.
D) They are a constituent of sterols.
E) They are strongly hydrophilic.
2.
Storage Lipids
Which of the following molecules or substances contain, or are derived from, fatty acids?
A) Beeswax
B) Prostaglandins
C) Sphingolipids
D) Triacylglycerols
E) All of the above contain or are derived from fatty acids.
3.
Storage Lipids
Which of the following statements is true of lipids?
A) Many contain fatty acids in ester or amide linkage.
B) Most are simply polymers of isoprene.
C) Testosterone is an important sphingolipid found in myelin.
D) They are more soluble in water than in chloroform.
E) They play only passive roles as energy-storage molecules.
4.
Structural lipids in membranes
Which of the following contains an ether-linked alkyl group?
A) Cerebrosides
B) Gangliosides
C) Phosphatidyl serine
D) Platelet-activating factor
E) Sphingomyelin
5.
Structural lipids in membranes
Which of the following statements about membrane lipids is true?
A) Glycerophospholipids are found only in the membranes of plant cells.
B) Glycerophospholipids contain fatty acids linked to glycerol through amide bonds.
C) Lecithin (phosphatidylcholine), which is used as an emulsifier in margarine and chocolate, is a sphingolipid.
D) Some sphingolipids include oligosaccharides in their structure.
E) Triacylglycerols are the principal components of erythrocyte membranes.
6.
Structural lipids in membranes
Which of the following is not true of sterols?
A) Cholesterol is a sterol that is commonly found in mammals.
B) They are commonly found in bacterial membranes.
C) They are more common in plasma membranes than in intracellular membranes (mitochondria, lysosomes, etc.).
D) They are precursors of steroid hormones.
E) They have a structure that includes four fused rings.
7.
Structural lipids in membranes
Which of the following best describes the cholesterol molecule?
A) Amphipathic
B) Nonpolar, charged
C) Nonpolar, uncharged
D) Polar, charged
E) Polar, uncharged
Lipids
8.
Lipids as signals, cofactors, and pigments
Which of the following is not a fat-soluble vitamin?
A) A
B) C
C) D
D) E
E) K
9.
Lipids as signals, cofactors, and pigments
Which vitamin is derived from cholesterol?
A) A
B) B12
C) D
D) E
E) K
10. Lipids as signals, cofactors, and pigments
Identify the molecule(s) derived from sterols.
A)
B)
C)
D)
E)
Arachidonic acid
Gangliosides
Phosphatidylglycerol
Prostaglandins
Vitamin D
11. Solute transport across membranes
The type of membrane transport that uses ion gradients as the energy source is:
A) facilitated diffusion
B) passive transport.
C) primary active transport.
D) secondary active transport.
E) simple diffusion.
39. Fill in the blanks. The eicosanoid hormones, which mediate pain and inflammation, are derived from the fatty acid
____________, released from a membrane phospholipid through the action of the enzyme ________________.
A. phosphatidylcholine, phospholipase C.
B. arachidonic acid, phospholipase A
C. palmitic acid, adenylyl cyclase.
D. phosphatidylcholine, leukotriene A.
E. cholesterol, prostaglandin A.
Lipids and Membranes
1. Which of the following lipids contains phosphate?
A. cholesterol
B. cerebroside
C. diacylglycerol
D. sphingomyelin
2. Fatty acids are stored in mammals as
A. free fatty acids
B. triacylglycerols
C. phosphatidylcholine
D. cholesterol
4. Which of the following is not a major component of biological membranes?
A. phosphatidylcholine
B. phosphatidylserine
C. cholesterol
D. triacylglycerol
5. Of the glycerophospholipids, sphingomyelin is structurally most similar to:
A. phosphatidylcholine.
B. phosphatidylethanolamine.
C. phosphatidylserine.
D. phosphatidylinositol.
6. Which of the following classes of lipids is not derived from arachidonic acid?
A. prostaglandins
B. thromboxanes
C. leukotrienes
D. isoprenoids
7. What is the following fatty acids contains 18 carbons and two double bonds??
A. linoleate
B. arachidonate
C. palmitate
D. oleate
8. The Na+,K+-ATPase, which pumps three Na+ ions out of a cell and two K+ ions into a cell is a(n)
A. passive symporter.
B. passive antiporter.
C. active symporter.
D. active antiporter.
9. Which of the following statements is TRUE about biological membranes?
A. Biological membranes do not contain cholesterol.
B. Biological membranes are predominantly composed of triacylglycerols.
C. The fluidity of biological membranes is affected by the presence and number of double bonds in fatty acids.
D. Biological membranes exclude proteins from the lipid bilayer.
10. Fill in the blanks. The eicosanoid hormones, which mediate pain and inflammation, are derived from the fatty acid
________, released from a membrane phospholipid through the action of the enzyme _________
A. phosphatidylcholine, phospholipase C.
B. arachidonic acid, phospholipase A
C. palmitic acid, adenylyl cyclase.
D. phosphatidylcholine, leukotriene A.
Lipids
11. Palmitate is denoted by
A. 18:2912
B. 18:19
C. 18:0
D. 16:0
12. Stearate is denoted by
A. 18:19
B. 18:391215
C. 16:19
D. 18:0
13. Oleate is denoted by
A. 18:2912
B. 18:19
C. 14:0
D. 16:0
14. Linolenate is denoted by
A. 18:391215
B. 18:19
C. 16:391215
D. 16:2912
15. Which of the following fatty acids has the highest melting temperature?
A. palmitate
B. stearate
C. oleate
D. linolenate
16. Which of the following fatty acids has the lowest melting temperature?
A. palmitate
B. stearate
C. oleate
D. linolenate
17. Which of the following is a membrane lipid with two fatty acids esterified to a glycerol backbone?
A. Plasmalogen
B. glycerophospholipid
C. triacylglycerol
D. ceramide
18. Which of the following is a membrane lipid a fatty acid ether-linked to a glycerol backbone?
A. Plasmalogen
B. glycerophospholipid
C. triacylglycerol
D. ceramide
19. Which of the following is a membrane lipid with an amide-linked fatty acid?
A. Plasmalogen
B. glycerophospholipid
C. triacylglycerol
D. ceramide
20. Which of the following lipids is a precursor for steroid hormone synthesis?
A. Cholesterol
B. Vitamin E
C. plasmalogen
D. glycosphingolipid
Lipids
1. Which of the following lipids is the most hydrophobic?
a. phosphatidylcholine
b. triacylglycerol
c. sphingomyelin
d. ceramide
2. Fatty acids are stored in mammals as
a. free fatty acids.
b. triacylglycerol.
c. phosphatidylcholine.
d. cholesterol
3. Which of the following is not a major component of biological membranes?
a. phosphatidylcholine
b. sphingomyelin
c. cholesterol
d. triacylglycerol
4. Thromboxanes, leukotrienes, and prostaglandins are derived from which fatty acid?
a. oleic acid
b. stearic acid
c. arachidonic acid
d. palmitic acid
5. Which of the following statements is true of fatty acids found in most mammalian cells?
a. They usually contain between 12 and 20 carbons.
b. All double bonds are in the trans configuration.
c. Free fatty acids are protonated and uncharged at physiological pH.
d. They are soluble in the aqueous cellular solution at physiological pH.
6. The Na+,K+-ATPase, which pumps two potassium ions into a cell, and three sodium ions out of a cell against a
concentration gradient, is an example of a
a. passive uniporter.
b. passive antiporter.
c. active symporter.
d. active antiporter.
7. The process whereby macromolecules are engulfed by the plasma membrane and brought into a cell inside a lipid vesicle is
a. Signal transduction
b. Endocytosis
c. Exocytosis
d. passive transport
8. Which of the following lipids is a precursor for steroid hormone synthesis?
a. Triacylglycerols
b. Cholesterol
c. Glycerophospholipids
d. Gangliosides
9. Which of the following lipids are ether-linked lipids abundant in the heart?
a. Triacylglycerols
b. Cholesterol
c. Glycerophospholipids
d. Plasmalogens
10. Which of the following lipids contains an oligosaccharide chain attached to a ceramide?
a. Triacylglycerols
b. Cholesterol
c. Glycerophospholipids
d. Gangliosides
Lipids
Draw the chemical structures of palmitate, oleate, linoleate, stearate, and arachidonate.
Draw the chemical structure of a triacylglycerol. Name the fatty acids.
Draw the chemical structures of phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine. Name the fatty acids.