C2-2 Carbon Cycle

Question 1

Carbon serves a dual purpose for organisms

Answer 1

1. it is a structural component of organic molecules

2. chemical bonds in carbon compounds provide metabolic energy

Question 2

Carbon cycle begins with

Answer 2

photosynthetic organisms taking up carbon dioxide (CO2)

Question 3

A process when carbon is changed from gaseous CO2 to less-mobile organic molecules.

Answer 3

Carbon fixation

Question 4

Enormous amounts of carbon also are locked up as ____ in the shells and skeletons of marine organisms, from tiny protozoans to corals.

Answer 4

Calcium carbonate (CaCO3)

Question 5

Geologists estimate that every carbon atom on the earth has made about _____ such round-trips over the past 4 billion years.

Answer 5

30

Question 6

When carbon is released from these sinks, as when we burn fossil fuels and inject CO2 into the atmosphere, or when we clear extensive forests, (what will happen?)

Answer 6

natural recycling systems may not be able to keep up, which is the root of global warming problem.

Question 7

Alternatively, extra atmospheric CO2 could support what?

Answer 7

support faster plant growth, speeding some of the recycling processes.