L2 - Adventures of carbon Flashcards
Why is carbon important to life?
Carbon is the backbone of organic molecules and can form four covalent bonds, allowing for molecular diversity.
What makes carbon versatile in biochemical systems?
Carbon can bond with itself and other elements to form diverse structures (chains, rings, branched molecules). It also forms strong, stable bonds without high energy costs.
What are the four major types of carbon-based biomolecules?
Carbohydrates – Energy flow
Lipids – Energy storage
Proteins – Structural & metabolic functions
Nucleic acids – Genetic information
Where is carbon stored in geological systems?
Carbon is stored in limestone (CaCO₃), fossil fuels, and the atmosphere (CO₂).
What happens when limestone is heated in a kiln?
It is heated to 1200-1400K, causing calcium carbonate (CaCO₃) to break down into calcium oxide (CaO) and carbon dioxide (CO₂), releasing CO₂ into the atmosphere.
What happens to atmospheric CO₂ after it is released?
It dissolves in seawater or remains in the atmosphere until absorbed by plants through photosynthesis.
What is the equation for photosynthesis?
6CO2+6H2O→C6H12O6 + 6O2
What happens to the glucose produced in photosynthesis?
it is converted into sucrose for transport and can be stored as starch (amylose) in plant tissues.
How does a human consume and digest carbon-containing molecules?
Starch is broken down into glucose by digestive enzymes and absorbed into the bloodstream via active transport in the small intestine.
What are two possible fates of glucose after absorption?
Burned for energy via aerobic respiration.
Converted into fat (triglycerides - TAGs) if excess energy is consumed.
What is the equation for aerobic respiration?
C6H12O6+6O2→6CO2+6H2O+Energy
What happens if a carbon atom is captured by a blade of grass instead?
Instead of being eaten by a human, the grass containing the carbon atom may be consumed by a cow on a cattle station.
How does ruminant digestion differ from human digestion?
In cows, microbial fermentation breaks down carbohydrates in the rumen, and most glucose is consumed by microbes instead of being directly absorbed by the cow.
What happens to methane (CH₄) released by ruminants?
It enters the atmosphere, where it is oxidized over ~10 years into CO₂ and H₂O or consumed by methanotrophic bacteria in soil.
Why is carbon cycling important?
It ensures continuous recycling of carbon between geological, biological, and atmospheric systems, allowing for energy flow and biochemical processes.
