Proteins and Enzymes 1.5 video Quiz

Priya, Michael, and Aria are studying for their biology exam. They come across a question about enzymes. They want to know, in the context of an enzyme, where does a substrate specifically bind?

• Active site

• Inactive site

• Binding site

• Catalytic site

Answer explanation

The specific area in an enzyme where substrates bind is known as the 'Active site'. This is the region of an enzyme where substrate molecules bind and undergo a chemical reaction. The other options, 'Inactive site', 'Binding site', and 'Catalytic site', are not the correct terms for this specific area.

During a biology experiment, Jackson, Mason, and Michael were observing the reaction of an enzyme with a substrate. What happens to the active site of the enzyme when the substrate binds during their experiment?

• It becomes more rigid

• It changes its shape to bind the substrate

• It becomes inactive

• It releases the substrate

Answer explanation

The active site of an enzyme changes its shape to bind the substrate. This is known as 'induced fit', where the enzyme modifies its shape to accommodate the substrate, facilitating the reaction. This is why the correct answer to the question is 'It changes its shape to bind the substrate'.

Evelyn and Elijah are in a biology class. Their teacher, Maya, demonstrates an experiment where she mixes two substances and they react to form a new substance. What is the name of the resulting item when these substrates bind and are acted upon by an enzyme?

• Substrate

• Enzyme

• Product

• Catalyst

Answer explanation

The question asks about the result when substrates bind and are acted upon by an enzyme. The correct answer is 'Product'. This is because, in a biochemical reaction, when an enzyme acts on a substrate, it converts the substrate into a different molecule, which is referred to as the 'product' of the reaction.

David and Luna are baking a cake. They are using an enzyme to speed up the reaction. What is the function of this enzyme in their baking process?

• To break down the ingredients

• To build up the ingredients

• To stabilize the ingredients

• To increase the concentration of ingredients

Answer explanation

Enzymes function to speed up reactions by lowering the activation energy required for the reaction to occur. The correct answer is 'To build up substrates'. This is because enzymes can catalyze reactions that build up substrates into larger molecules, a process known as anabolism. They do not break down, stabilize, or increase the concentration of substrates.

Abigail, Michael, and Aiden are conducting a science experiment in school. They are testing different enzymes on various substances. They want to know which enzyme is responsible for breaking down lactose into smaller parts. Can you help them?

• Lipase

• Amylase

• Protease

• Lactase

Answer explanation

The enzyme responsible for breaking down lactose into smaller parts is Lactase. Lactase is specifically designed to break down lactose, a sugar found in milk and dairy products. Other enzymes like Lipase, Amylase, and Protease do not have this specific function. Therefore, the correct answer to the question is Lactase.

Maya and Benjamin went to a local ice cream parlor. Benjamin could eat ice cream without any issues, but Maya felt discomfort after eating ice cream. What could be the term for individuals like Maya who do not produce enough lactase enzymes?

• Lactose intolerant

• Lactose sensitive

• Lactose deficient

• Lactose resistant

Answer explanation

The term for individuals who do not produce enough lactase enzymes is 'Lactose intolerant'. Lactase is an enzyme that breaks down lactose, a sugar found in milk and dairy products. When the body doesn't produce enough lactase, it can't properly digest lactose, leading to symptoms of lactose intolerance. The other options, 'Lactose sensitive', 'Lactose deficient', and 'Lactose resistant', do not accurately describe this condition.

Michael, Aiden, and Abigail are studying enzymes in their biology class. They learned that some substances bind to the active site or substrate to help the enzyme function. What are these substances called?

• Cofactors

• Coenzymes

• Substrates

• Products

Answer explanation

The correct answer is Cofactors. Cofactors are substances that bind to the active site or substrate of an enzyme, helping it to function properly. They can be inorganic ions or complex organic molecules called coenzymes. Substrates are the molecules that enzymes act upon, while products are the result of the enzymatic reaction.

Aria is learning about the human digestive system and wants to know the ideal pH for an enzyme in the stomach. What would you tell her?

• Neutral

• Basic

• Slightly acidic

• Very acidic

Answer explanation

The ideal pH for an enzyme in the stomach is very acidic. Stomach enzymes, such as pepsin, require an acidic environment to function effectively in breaking down proteins. The stomach's pH typically ranges from 1.5 to 3.5, which is highly acidic and suitable for these enzymes to work efficiently.

Abigail is conducting a science experiment and she changes the pH and temperature of the environment where an enzyme is present. What happens to the enzyme when the environment changes out of its ideal pH or temperature range?

• It becomes denatured

• It becomes more active

• It becomes inactive

• It changes its shape

Answer explanation

Enzymes are proteins that function best within specific pH and temperature ranges. When the environment changes out of its ideal pH or temperature range, the enzyme becomes denatured. Denaturation causes the enzyme to lose its shape and functionality, rendering it unable to catalyze reactions effectively.

Anika, Ava, and Aria are conducting a science experiment to determine which enzyme breaks down lipids. Which enzyme should they use?

• Lipase

• Amylase

• Protease

• Lactase

Answer explanation

Lipase is the enzyme responsible for breaking down lipids. Lipids are a type of fat molecule, and lipase helps to digest and absorb these molecules in the body. The other options, amylase, protease, and lactase, are enzymes that break down different types of molecules: amylase breaks down carbohydrates, protease breaks down proteins, and lactase breaks down lactose, a sugar found in milk.