Carbon Basics
What form of carbon do plants take from the atmosphere?
Carbon dioxide (CO₂)
Which process builds glucose: photosynthesis or respiration?
Photosynthesis
Which reservoir stores the most carbon long-term?
The geosphere (rocks, fossil fuels)
Burning which resources adds extra carbon dioxide to the atmosphere?
Fossil fuels (coal, oil, natural gas)
What direction does carbon move in photosynthesis: atmosphere to what?
Biosphere
What type of molecule stores carbon in living things?
Organic molecules like glucose, carbohydrates, lipids, proteins
Which process breaks down glucose for energy?
Cellular respiration
What role does the ocean play in the carbon cycle?
Absorbs and releases CO₂, storing carbon as dissolved carbonates
Deforestation affects which process in the carbon cycle?
Photosynthesis (fewer trees absorb less CO₂)
Respiration moves carbon from the biosphere to which reservoir?
Atmosphere
Which process removes carbon from the atmosphere?
Photosynthesis
What is the basic equation for photosynthesis?
CO₂ + H₂O + sunlight → C₆H₁₂O₆ + O₂
Which reservoir includes plants and animals?
The biosphere
What is the greenhouse effect?
Trapping of heat in Earth’s atmosphere by gases like CO₂
Decomposition connects which two reservoirs?
Biosphere and geosphere (soil/fossil fuels) or atmosphere (CO₂)
Name two processes that return carbon to the atmosphere.
Respiration and combustion
What is the basic equation for respiration?
C₆H₁₂O₆ + O₂ → CO₂ + H₂O + energy (ATP)
How does carbon move from the atmosphere to the hydrosphere?
Dissolving of CO₂ into ocean water
How does ocean acidification relate to the carbon cycle?
Excess CO₂ dissolves in oceans, forming carbonic acid, harming marine life
Describe one arrow on a carbon cycle diagram showing combustion.
Geosphere (fossil fuels) to atmosphere (CO₂)
What is the main greenhouse gas involved in the carbon cycle?
Carbon dioxide (CO₂)
How are photosynthesis and respiration complementary in the carbon cycle?
Photosynthesis removes CO₂ and makes glucose; respiration releases CO₂ by breaking down glucose
How does decomposition connect the biosphere and geosphere?
Dead organisms decompose, and carbon can become fossil fuels or soil carbon
Give one human activity that moves carbon from the geosphere to the atmosphere.
Combustion of fossil fuels
Why do scientists use models to represent the carbon cycle?
To simplify complex interactions among reservoirs and processes