Module 3: Section 1B

Question 1

Central components in biosynthesis

Answer 1

• Carbon
• Nitrogen

Question 2

Minor components in biosynthesis

Answer 2

• Vitamins
• Hydrogen
• Trace elements

Question 3

Prokaryotes in the carbon cycle

Answer 3

• Photosynthetic decomposers break down dead organic material (a carbon source)
• They release carbon in the form of carbon dioxide back into the atmosphere via cellular respiration

Question 4

Prokaryotes in the nitrogen cycle

Answer 4

• Produce energy through conversion of ammonia to nitrites and nitrates
• Others oxidize nitrates for their energy needs

Question 5

2 energy sources

Answer 5

1. Chemotrophic
2. Phototrophic

Question 6

Chemotrophic

Answer 6

Organisms obtain energy from external chemical compounds

Question 7

Phototrophic

Answer 7

Organisms obtain energy from light

Question 8

3 ways organisms obtain carbon

Answer 8

1. Autotrophic
2. Heterotrophic
3. Mixotrophs

Question 9

Autotrophic

Answer 9

Organisms obtain carbon from carbon dioxide

Question 10

Heterotrophic

Answer 10

Carbon is obtained from organic compounds

Question 11

Mixotrophs

Answer 11

Organisms that use both organic compounds and carbon dioxide to obtain carbon

Question 12

Two ways organisms obtain electrons

Answer 12

• Lithotrophic
• Organotrophic

Question 13

Lithotrophic

Answer 13

Organisms obtain reduction equivalents from inorganic compounds

Question 14

Organotrophic

Answer 14

Organisms use organic compounds as their source of electrons

Question 15

Photoautotrophs

Answer 15

• Use H2O, as the electron source to reduce carbon dioxide and produce O2
• Plants, algae, cynobacteria

Question 16

Photoheterotrophs

Answer 16

• Organisms that use light for energy and get carbon from organic compounds
• Green or purple non-sulfur bacteria, some archaea

Question 17

Chemoautotrophs

Answer 17

• Organisms that get energy by oxidizing inorganic molecules and use CO₂ as their carbon source
• Hydrogen, sulfur, and nitrifying bacteria
• Some archaea

Question 18

Chemoheterotrophs

Answer 18

• Organisms that get both energy and carbon from organic compounds
• Ex: Aerobic respiration organisms, anaerobic respiration organisms, and fermentation organisms

Question 19

What fuels anabolic processes?

Answer 19

An energy source, carbon source and electron source are all required for cell growth