UIL Biology Topic 3: Energy Transformations Questions

What is the main purpose of cellular respiration?

• To produce glucose

• To generate ATP

• To store energy

• To synthesize proteins

• To break down lipids

Answer explanation

The main purpose of cellular respiration is to generate ATP, which is the energy currency of the cell. While glucose is used in the process, the primary goal is to convert energy stored in glucose into ATP for cellular functions.

Which molecule is the primary energy carrier in cells?

• NADH

• FADH2

• ATP

• ADP

• GTP

Answer explanation

ATP (adenosine triphosphate) is the primary energy carrier in cells, providing energy for various cellular processes. While NADH and FADH2 are important for energy production, ATP is the direct energy source used by cells.

Tags

NGSS.HS-LS1-7

Which organelle is primarily involved in photosynthesis?

• Mitochondrion

• Chloroplast

• Ribosome

• Nucleus

• Golgi apparatus

Answer explanation

The chloroplast is the organelle responsible for photosynthesis, converting light energy into chemical energy in plants. Mitochondria are involved in respiration, while ribosomes, the nucleus, and Golgi apparatus have different functions.

Tags

NGSS.HS-LS1-5

NGSS.HS-LS2-5

What is the role of enzymes in biochemical reactions?

• They increase the activation energy

• They decrease the activation energy

• They are consumed in the reaction

• They provide energy for the reaction

• They change the reaction equilibrium

Answer explanation

Enzymes act as catalysts in biochemical reactions by lowering the activation energy required for the reaction to proceed, thus speeding up the reaction without being consumed or altering the equilibrium.

Which process converts glucose into pyruvate?

• Krebs cycle

• Glycolysis

• Electron transport chain

• Calvin cycle

• Fermentation

Answer explanation

Glycolysis is the metabolic process that converts glucose into pyruvate, occurring in the cytoplasm of cells. It is the first step in cellular respiration, while the other options refer to different metabolic pathways.

What gas is consumed during photosynthesis?

• Oxygen

• Nitrogen

• Carbon dioxide

• Hydrogen

• Methane

Answer explanation

During photosynthesis, plants consume carbon dioxide (CO2) from the atmosphere. This gas is essential for the process, as it is converted into glucose and oxygen, making carbon dioxide the correct answer.

Tags

NGSS.MS-LS1-6

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Which part of cellular respiration produces the most ATP?

• Glycolysis

• Krebs cycle

• Electron transport chain

• Fermentation

• Calvin cycle

Answer explanation

The electron transport chain produces the most ATP during cellular respiration by using electrons from NADH and FADH2 to create a proton gradient, which drives ATP synthesis through ATP synthase.

Tags

NGSS.HS-LS1-7

What is the primary pigment involved in photosynthesis?

• Carotene

• Xanthophyll

• Chlorophyll

• Anthocyanin

• Flavonoid

Answer explanation

Chlorophyll is the primary pigment in photosynthesis, responsible for capturing light energy. It primarily absorbs blue and red light, reflecting green, which is why plants appear green.

Which enzyme is responsible for carbon fixation in the Calvin cycle?

• ATP synthase

• Rubisco

• Hexokinase

• Phosphofructokinase

• Lactase

Answer explanation

Rubisco, or ribulose-1,5-bisphosphate carboxylase/oxygenase, is the key enzyme in the Calvin cycle that catalyzes the fixation of carbon dioxide, making it essential for photosynthesis.

What is the end product of glycolysis?

• Acetyl-CoA

• Oxaloacetate

• Pyruvate

• Lactic acid

• Ethanol

Answer explanation

The end product of glycolysis is pyruvate, which is formed from glucose through a series of enzymatic reactions. Acetyl-CoA, oxaloacetate, lactic acid, and ethanol are products of subsequent metabolic pathways.

Tags

NGSS.HS-LS1-7