Chemistry for Biologists

Energy flow

1. The main reason why green plants cannot use nitrogen directly from the air is:
the triple bonds holding the nitrogen atoms together in the molecule require too much energy to break them
the nitrogen molecule is too unstable
nitrogen gas dissolves in water to produce a strongly acidic solution which would damage the plant cells
nitrogen molecules are insoluble in water
2. In the water cycle, photosynthesis:
converts liquid water into solid water
converts glucose into water
converts gaseous water to liquid water
fixes hydrogen from water into biomass
3. In the carbon cycle, photosynthesis:
fixes carbon in biomass
fixes carbon in carbonates
releases carbon dioxide into the atmosphere
releases carbon dioxide from the oceans
4. Gross primary production is highest in:
a rainforest
a desert
5. A system’s productivity is measured in:
kJ m-1 yr-1
kJ m-2 yr-1
kJ m s-1
kJ m-2 s-1
6. The rate at which energy from sunlight is made available to consumers by green plants is known as a system’s:
growth rate
gross primary production
net primary production
7. In green plants, energy is stored mainly in:
8. When light energy is absorbed by chlorophyll during photosynthesis:
chlorophyll decomposes to form glucose and water
chlorophyll combines with carbon dioxide to produce glucose
a high energy electron is released from the chlorophyll molecule
chlorophyll is converted to ATP