Metabolism and Enzymes Quiz

What is the definition of metabolism?

• The synthesis of complex molecules from simple molecules

• The breakdown of complex substances into simple substances

• All chemical reactions that occur in a living organism

• The conversion of food into energy in the form of ATP

Which of the following is an example of catabolism?

• Synthesis of complex molecules from simple molecules

• Breakdown of glucose during cellular respiration

• Conversion of food into energy in the form of ATP

• Formation of glucose during photosynthesis

What is an enzyme?

• A type of nucleic acid that breaks down food

• A lipid that speeds up reactions in cells

• An organic catalyst mostly made up of proteins

• A type of carbohydrate in cells

How are enzymes named?

• By their color under a microscope

• By using a numbering system

• By adding '-ase' to the name of the substrate they catalyze

• Based on the type of cell they are found in

What is the 'lock and key' hypothesis in enzyme action?

• Enzymes are shaped like keys that fit into locks on substrates

• Enzymes are like keys that open doors in cells

• Enzymes are locks that prevent substrates from entering cells

• Enzymes and substrates have no specific interaction

Which of the following is a general characteristic of enzymes?

• They are not affected by temperature or pH

• They are destroyed after a reaction

• They are only required in large quantities

• They act rapidly

What are intracellular enzymes?

• Enzymes that are produced by living cell organisms

• Enzymes that are secreted outside the cell

• Enzymes that are used in the glycolysis process

• Enzymes that are only found in animal cells

What is the optimal temperature for enzyme reactions in the human body?

• 20°C

• 30°C

• 37°C

• 40°C

How does pH affect enzyme activities?

• All enzymes work best at a pH of 1.5-2.5

• Enzymes work best in an alkaline medium

• Enzymes are not affected by pH changes

• Most enzymes are most active at pH 6-8

What happens to enzymes at extreme temperatures?

• They become more active

• They are destroyed

• They denature and lose their three-dimensional form

• They stop working temporarily