Enzymes

All chemical breakdown processes in cells directly involve

• reactions that are controlled by catalysts

• enzymes that are stored in mitochondria

• the production of catalysts in vacuoles

• enzymes that have the same genetic base

The diagram below represents a series of reactions that can occur in an organism. This diagram best illustrates the relationship between

• enzymes and synthesis

• amino acids and glucose

• antigens and immunity

• ribosomes and sugars

Many disorders are due to the inability of an individual to break down a particular chemical. Sometimes these disorders can be treated by giving the affected individual the appropriate

• chromosomes

• antigens

• enzymes

• organelles

Fruits and vegetables exposed to air begin to brown because of a chemical reaction in their cells. This may result in these foods being thrown out. Some people have found that adding lemon juice (citric acid) to apple slices keeps them from turning brown. The prevention of browning is likely the result of

• increasing the concentration of enzymes

• increasing the temperature

• slowing the rate of enzyme action

• maintaining the pH

The process of transferring energy during respiration occurs in a series of steps. This prevents too much heat from being released at one time. Maintaining an appropriate temperature is beneficial to an organism because

• cellular waste products can only be excreted in cooler temperatures

• enzymes need a proper range of temperatures to catalyze vital reactions

• hormones can only produce antibodies if temperatures are not excessive

• nutrients diffuse faster into cells when temperatures are lower

Carmine, a compound that comes from the cochineal beetle, shown below, is used as a food coloring.

The food coloring is not harmful to most people, but in a small number of individuals, it causes a reaction and affects their ability to breathe. This response to carmine is known as

• a stimulus

• an allergy

• natural selection

• an adaptation

White blood cells are most closely associated with which two body systems?

• digestive and excretory

• excretory and immune

• immune and circulatory

• circulatory and digestive

When food is being mechanically digested, it is being

• excreted from the body

• converted into energy

• changed into another substance

• made smaller in size

Which gas is used by humans in the process of cellular respiration?

• methane

• nitrogen

• oxygen

• carbon dioxide

During the process of photosynthesis, green plants produce

• nitrogen

• methane

• sugar

• sunlight