Respiration & Photosynthesis Quiz

Which of the following is an example of an intracellular enzyme-catalyzed reaction?

• Glycolysis

• Chemical digestion in the gut

• Photosynthesis

• Fermentation

Answer explanation

Glycolysis is an intracellular process that occurs in the cytoplasm of cells, where glucose is broken down to produce energy. The other options involve extracellular processes or occur in different cellular compartments.

Which cycles are examples of cyclical pathways in metabolism?

• Glycolysis and the Calvin cycle

• Krebs cycle and Calvin cycle

• Glycolysis and Krebs cycle

• Calvin cycle and photosynthesis

Answer explanation

The Krebs cycle and Calvin cycle are both cyclical pathways in metabolism. The Krebs cycle is part of cellular respiration, while the Calvin cycle is involved in photosynthesis, both regenerating intermediates.

What is the function of an allosteric site in enzyme regulation?

• It binds to substrates permanently.

• It allows specific substances to bind, causing conformational changes.

• It prevents any binding to the enzyme.

• It enhances the enzyme's activity without binding.

Answer explanation

The allosteric site allows specific substances to bind, leading to conformational changes in the enzyme. This can enhance or inhibit enzyme activity, making it crucial for regulation.

Which pathway is used as an example of feedback inhibition?

• Pathway producing isoleucine

• Pathway producing glucose

• Pathway producing ATP

• Pathway producing oxygen

Answer explanation

The pathway producing isoleucine is a classic example of feedback inhibition, where the end product inhibits an earlier step in its own synthesis, preventing overproduction.

What is the full name of ATP?

• Adenosine diphosphate

• Adenosine triphosphate

• Adenosine monophosphate

• Adenosine tetraphosphate

Answer explanation

ATP stands for Adenosine triphosphate, which is a crucial energy carrier in cells. The other options refer to different forms of adenosine phosphates, but only 'Adenosine triphosphate' is correct.

Which type of respiration requires mitochondria?

• Anaerobic respiration

• Aerobic respiration

• Fermentation

• Photosynthesis

Answer explanation

Aerobic respiration requires mitochondria because it involves the use of oxygen to produce ATP, which occurs in the mitochondria. In contrast, anaerobic respiration and fermentation do not require mitochondria.

What is the net yield of ATP in glycolysis?

• 1 ATP

• 2 ATP

• 3 ATP

• 4 ATP

Answer explanation

In glycolysis, a total of 4 ATP are produced, but 2 ATP are consumed in the initial steps. Therefore, the net yield of ATP is 2 ATP.

What is the primary function of cell respiration?

• Produce glucose

• Generate ATP

• Store oxygen

• Create proteins

Answer explanation

The primary function of cell respiration is to generate ATP, which is the energy currency of the cell. While glucose is consumed during this process, the main goal is to produce ATP for cellular activities.

Which of the following is NOT a product of glycolysis?

• Pyruvate

• ATP

• NADH

• Oxygen

Answer explanation

Oxygen is not a product of glycolysis. The main products of glycolysis are pyruvate, ATP, and NADH, while oxygen is not directly involved in this anaerobic process.

Which molecule is reduced during cell respiration?

• ATP

• NAD

• Glucose

• Oxygen

Answer explanation

During cellular respiration, NAD (Nicotinamide adenine dinucleotide) is reduced to NADH as it accepts electrons. This process is crucial for energy production, while ATP and glucose are not reduced, and oxygen is typically the final electron acceptor.