Chemistry for Biologists

Energy flow

1. In the water cycle, photosynthesis:
converts gaseous water to liquid water
fixes hydrogen from water into biomass
converts glucose into water
converts liquid water into solid water
2. 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
3. A system’s productivity is measured in:
kJ m-1 yr-1
kJ m s-1
kJ m-2 yr-1
kJ m-2 s-1
4. Gross primary production is highest in:
a rainforest
a desert
5. 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
6. In green plants, energy is stored mainly in:
7. The rate at which energy from sunlight is made available to consumers by green plants is known as a system’s:
gross primary production
net primary production
growth rate
8. When light energy is absorbed by chlorophyll during photosynthesis:
chlorophyll is converted to ATP
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