Metabolic Pathways
Metabolic pathways are sequences of chemical reactions in cells that convert molecules into products, including cellular respiration, photosynthesis, and biosynthesis pathways.
What You Need to Know
Key Concept Diagram
Cellular respiration converts glucose to ATP in three stages: glycolysis, Krebs cycle, and oxidative phosphorylation
Photosynthesis converts light energy to chemical energy in glucose through light-dependent and light-independent reactions
Enzymes catalyse each step in metabolic pathways; their activity is affected by temperature, pH, and inhibitors
ATP is the universal energy currency of cells
Anabolic pathways build complex molecules; catabolic pathways break them down
Key Vocabulary
ATP
Adenosine triphosphate — the primary energy currency of cells
Glycolysis
The first stage of cellular respiration; glucose is broken down to pyruvate in the cytoplasm
Krebs cycle
A cycle of reactions in the mitochondrial matrix that releases carbon dioxide and energy carriers
Enzyme
A biological catalyst that speeds up metabolic reactions without being consumed
Knowledge Check
Select the correct answer for each question. Click "Check Answer" to see if you are right.
Question 1
How many ATP molecules are produced from the complete aerobic respiration of one glucose molecule?
Question 2
Which stage of cellular respiration occurs in the cytoplasm?
Question 3
In photosynthesis, where does the light-independent (Calvin cycle) stage occur?
Key Concepts Summary
- ●Cellular respiration converts glucose to ATP in three stages: glycolysis, Krebs cycle, and oxidative phosphorylation
- ●Photosynthesis converts light energy to chemical energy in glucose through light-dependent and light-independent reactions
- ●Enzymes catalyse each step in metabolic pathways; their activity is affected by temperature, pH, and inhibitors
- ●ATP is the universal energy currency of cells
- ●Anabolic pathways build complex molecules; catabolic pathways break them down