OnRamps Midterm Review

Choose all molecules that contain a polar region and will form hydrogen bonds with other polar molecules.

• 
• 
• 
• 
• 

Choose the incorrect description of the black dots in the Lewis structures.  

• Areas of partial negative charge

• Lone pairs of electrons

• Outer shell electrons

• Areas where ionic bonds can form

• Areas where hydrogen bonds can form

Glycogen is composed of alpha glucose monomers and functions as a short term energy storage molecule.  When blood glucose levels are high, excess glucose is stored as glycogen in the liver and muscles.  What happens to glycogen when blood sugar levels drop?

• Glycogen is broken down by condensation and glucose is released into the blood.

• Glycogen is broken down by hydrolysis and glucose is released into the blood.

• Glycogen is broken down by dehydration and glucose is released into the blood.

• Glycogen is converted to fats for longer-term energy storage.

One function of the polysaccharides is to provide rigid cell structures for animals and plants.  Which of these polysaccharides is a structural carbohydrate found in plant cell walls? 

• glycogen

• amylopectin

• starch

• cellulose

Monosaccharides are covalently joined together by glycosidic bonds to form disaccharides and polysaccharides which function as energy storage and structural carbohydrates.  Three examples of monosaccharides would include

• glucose, sucrose, cellulose

• glycogen, cellulose, starch

• lactose, sucrose, maltose

• glucose, fructose, and galactose

Which of the following biomolecules contains the highest amount of energy in number of calories per gram?

• triglycerides or fats

• Beta-glucose polymers

• cellulose

• chitin

Water is a product of dehydration (aka condensation) reactions that unite monomers into longer polymers.  What is the source of the atoms that make up the water molecule?

• The atoms come from the enzyme that catalyzes the reaction.

• Only one of the monomers donates atoms.

• The water is donated by hydrolysis.

• Both of the monomers donate atoms.

Fats and oils consist of three fatty acids attached to a glycerol backbone.  The ester bond forms between the carboxyl group of the fatty acids and the hydroxyl group of the glycerol molecules.

 How many water molecules are required in the anabolic synthesis of a triglyceride? 

• 3, hydrolysis consumes water molecules.

• 0, hydrolysis produces water molecules.

• 3, condensation produces water molecules.

• 0, condensation produces water molecules.

Which letter indicates the ester linkage that forms between the carboxyl group of the fatty acid and the hydroxyl group of the glycerol?

• A

• B

• C

• D

In the synthesis of DNA and RNA, nucleotides are covalently bonded by phosphodiester bonds to growing strands.  How does the phosphodiester bond form?

• Between the hydroxyl group on the 3' carbon and the phosphate group of the next nucleotide.

• Between the phosphate group on the 3' carbon and the hydroxyl group of the next nucleotide.

• Between the 3' and 5' hydroxyl groups.

• Between the hydroxyl group on the 5' carbon and the phosphate group of the next nucleotide.