8.1

Question 1

Autotrophs

Answer 1

Produce their own ATP and organic molecules through photosynthesis
-plants, algae, photosynthetic bacteria

Question 2

Heterotrophs

Answer 2

(95% species)
-live on organic molecules produced by autotrophs
-animals, fungi, prokaryotes

Question 3

Harvested electrons undergo a series of redox reactions

Answer 3

-Electrons harvested from organic molecules posses energy
- redox reactions transfer electrons and associated energy
- electrons lose some energy with each transfer
-released energy may be lost as heat or may eventually be converted into ATP
-after multiple redox reaction, energy depleted electrons are transfers to final electron acceptor molecule

Question 4

Transfer often involves cofactors working as electron carriers

Answer 4

-Many electron carriers exist-most are cofactors
- all are easily and reversible oxidized and reduced
-NAD+ accepts 2 electrons and 1 proton to become NADH

Question 5

Aerobic respiration of glucose

Answer 5

C6H12O6 +602 -> 6CO2 +6H2O + energy

-final electron accepted is O2
Delta G=-686 Kcal/mol glucose
-energy must be harvested in small steps
-these small steps involve electron carriers