Biomolecules & Enzymes

Vegetable oils, such as corn oil, belong to which general class of organic substances?

• lipids
• proteins
• carbohydrates
• salts

Organic compounds in which molecules are made up of building blocks containing amino groups are classified as

• proteins
• carbohydrates
• lipids
• fatty acids

Which types of compounds are NOT classified as carbohydrates?

• lipids
• sugars
• starches
• polysaccharides

All carbohydrates are compounds that contain the elements

• iron, magnesium, and carbon
• oxygen, hydrogen, and nitrogen
• carbon, oxygen, and nitrogen
• carbon, hydrogen, and oxygen

Which organic molecule is correctly paired with an end product of its digestion?

• nucleic acid - glycerol
• carbohydrate - fatty acid
• protein - amino acid
• lipid - nucleotide

Which is a characteristic of an enzyme?

• It is an inorganic catalyst.
• It is destroyed after each chemical reaction.
• It provides energy for any chemical reaction.
• It speeds up the rate of a specific chemical reaction.

A student place a test tube containing a mixture of compounds into a beaker of water maintained at 30 degrees C. A chemical reaction took place and was completed in 30 minutes. A second test tube containing an equal amount of the same mixture plus substance Y was placed in the same beaker of water. The chemical reaction in the second test tube was completed in less than one minute. Substance Y was most likely

• an auxin
• an enzyme
• a sugar
• a nucleotide

The structural formula shown represents a compound that may serve as the building block of

• carbohydrates
• fats
• proteins
• vitamins

Graph I shows the relationship between the relative rates of activity of enzymes A and B and temperature. Graph II shows the relationship between the relative rates of activity of enzymes A and B and pH.
Under which conditions is enzyme A most effective?

• at 40* C and pH of 5
• at 45* C and pH of 5
• at 45* C and a pH of 9
• at 50* C and a pH of 9

The distortion (change in shape) of enzyme molecules which occurs at high temperatures is known as

• synthesis
• specificity
• replication
• denaturation