Metabolism

Benjamin is running a race and his body needs a substance to release energy. Which of the following is used to release energy and is made of carbon, hydrogen, and oxygen atoms?

• used to release energy, made of carbon, hydrogen, and oxygen atoms

• molecules that are the building blocks of proteins

• a molecule made of carbon and oxygen atoms

• a gas needed for respiration in living things

In a bakery, Priya is analyzing how a large sugar molecule, fructose 1,6-bisphosphate, is split into two smaller sugar fragments during the dough fermentation process. Which enzyme catalyses this reaction?

• ligases

• isomerases

• synthases

• lyases

During a biology experiment, Rosie is studying how cells communicate with each other. She learns that certain reactions are crucial for passing signals inside the cell. Which type of reaction is primarily involved in these signal transduction pathways?

• Oxidation-reduction reactions

• Group-transfer reactions

• Isomerisation reactions

• Condensation reactions

Rosie is shadowing a doctor in a hospital and observes a patient who has been fasting for several days. The doctor explains that the patient's body is undergoing ketogenesis. What is ketogenesis?

• production of Acetyl-CoA

• ketones come to brain

• conversion of acetyl CoA to ketones

• None of this

Answer explanation

Ketogenesis is the process where acetyl-CoA is converted into ketones, primarily in the liver. This is crucial during fasting or low-carbohydrate intake, providing an alternative energy source for the brain and other tissues.

Jacob is studying how cells produce energy and is learning about the electron transport chain. Which of the following statements is not true about what happens in the electron transport chain?

• Occurs in the inner mitochondrial membrane

• Produces water as a by-product

• Directly generates ATP

• Involves a series of redox reactions

Answer explanation

The electron transport chain does not directly generate ATP; instead, it creates a proton gradient that drives ATP synthesis via ATP synthase. The other statements about its location, byproducts, and redox reactions are true.

Emily is running a marathon and her muscles need a quick source of energy to keep her going. What is the primary function of ATP in her cells during this activity?

• To store genetic information

• To provide energy for cellular activities

• To act as a structural component of cell membranes

• To serve as a catalyst in biochemical reactions

During a science experiment, Sophie accidentally spills hydrogen peroxide on the lab table. She remembers that a certain enzyme can quickly break down hydrogen peroxide into water and oxygen, making the cleanup safer. Which enzyme is responsible for this reaction?

• Amylase

• Catalase

• Lipase

• Protease