4/16 daily eoc work

Many plants have waxy coatings on some surfaces. This coating reduces water loss because it is not water-permeable. This waxy coating is which of the following types of organic molecule?

• protein

• carbohydrate

• nucleic acid

• lipid

Like complex carbohydrates, proteins are macromolecules that serve many functions and can be chemically broken down and restructured. Both proteins and complex carbohydrates are which of the following?

• polymers of smaller subunits

• sequence of sugars

• lipids of large molecules

• nucleotides of DNA

What is the function of the macromolecule subunit below?

• energy

• catalyst

• stores genetic information

• composes the majority of the cell membrane

The diagram below shows a monomer of a macromolecule. Which of the following macromolecules contains these monomers?

• carbohydrates

• proteins

• nucleic acids

• lipids

Some bacteria live in hot springs. Their cells contain enzymes that function best at temperatures of 70 °C or higher. At the temperature of 50 °C, how will the enzymes in these bacterial cells most likely be affected?

• The enzymes will be destroyed by lysosomes.

• The enzymes will lose their bond structure and fall apart.

• The enzymes will require less energy to function than at 70°C.

• The enzymes will not increase the rate of reactions as much as they would at 70°C.

Many of the proteins in the human body are enzymes that catalyze chemical reactions. What is the relationship between enzymes and activation energy?

• When an enzyme catalyzes a reaction, it increases the activation energy of the reaction

• When an enzyme catalyzes a reaction, it increases the activation energy of the product.

• When an enzyme catalyzes a reaction, it decreases the activation energy of the reaction.

• When an enzyme catalyzes a reaction, it does not affect the activation energy of the reaction.

Meat tenderizer contains an enzyme that breaks down meat. If meat is coated with tenderizer and then placed in a refrigerator, predict how the enzyme might be affected?

• It would break down the meat more slowly.

• It would disintegrate the meat.

• It would break down the meat more quickly.

• It would change the shape of the meat.

As food travels through the digestive system, it is exposed to a variety of pH levels. The stomach has a pH of 2 due to the presence of hydrochloric acid (HCl), and the small intestine has a pH ranging from 7 to 9. HCl converts pepsinogen into pepsin, an enzyme that digests proteins in the stomach. Which of the following most likely happens to pepsin as it enters the small intestine?

• It becomes inactive.

• It begins to replicate.

• Its shape changes to engulf large proteins.

• Its activity increases to digest more proteins.

The graph below shows how the activity of an enzyme changes over a range of pH values.

Which of the following conclusions can be drawn from this graph?

• The optimum pH of the enzyme is 6.6

• The optimum pH of the enzyme is 5.8

• The enzyme’s activity continually increases as pH increases from 5.0 to 9.0

• The enzyme’s activity is greater around pH of 8.0 than around pH of 5.0.

The diagram below illustrates a biochemical process that occurs in organisms.

What is another name for the substance labeled "catalyst"?

• enzyme

• inorganic compound

• hormone

• antibody