Nutritional Types and Energy Production

Question 1

define organic (for this class)

Answer 1

• 2+ carbon atoms present
• 1+ hydrogen atoms present

Question 2

what do all organisms require in large amounts?

Answer 2

• macroelements: C, O, H, N, S, P (found in organic molecules like proteins, lipids, carbs, and nucleic acids
• also included are K+, Ca2+, Mg2+, Fe2+, and Fe3+: required for protection, stabilize ribosomes and cell membranes, iron makes up ETC

Question 3

heterotrophs

Answer 3

use reduced, preformed organic molecules as their carbon source (ex: glucose, fats, proteins)
(reduced: molecule has electrons to give, makes sense given ETC)

Question 4

autotrophs

Answer 4

get their carbon from CO2: fix CO2 into organic materials (think photosynthesis!)

Question 5

trace elements

Answer 5

• required by organisms in small amounts
• zinc, cobalt, nickel, copper, etc.
• parts of certain enzymes and cofactors
• help catalyze important metabolic rxns

Question 6

3 ways to gain energy

Answer 6

• trap light energy: phototrophs
• oxidate (eat) organic molecules: chemoorganotrophs
• oxidate (eat) inorganic molecules: chemolithotrophs

Question 7

organotroph

Answer 7

gets electrons from organic molecules

Question 8

lithotroph

Answer 8

gets electrons from inorganic molecules

Question 9

3 types of nutritional groups we need to know

Answer 9

• photolithoautotroph
• chemolithoautotroph
• chemoorganoheterotroph

Question 10

photolithoautotroph

Answer 10

energy source: sun
electron source: inorganic chemicals
carbon source: cardon dioxide
- plants and algae, cyanobacteria, purple/green bacteria

Question 11

what are three things that organisms need?

Answer 11

• energy source
• electron source
• carbon source

Question 12

chemolithoautotroph

Answer 12

energy source: inorganic chemicals
electron source: inorganic chemicals
carbon source: carbon dioxide
- sulfur-oxidizing bacteria, H2-oxidizing bacteria, methanogens

Question 13

chemoorganotrophs

Answer 13

energy source: organic chemicals
electron source: organic chemicals
carbon source: organic chemicals
- humans, animals, bacteria (pathogens), fungi, protozoa

Question 14

three types of work

Answer 14

• chemical work: synthesis of molecules (anabolism)
• transport work: active transport
• mechanical work: moving an organism
  –> these need energy to be done!!

Question 15

where does most energy come from?

Answer 15

sunlight!!

Question 16

redox rule of thumb

Answer 16

• a molecule becomes oxidized if it: loses H, gains O, increases + charge or decreases - charge
• a molecule becomes reduced if: loses O, gains H, decreases + charge or increases - charge

Question 17

standard reduction potential (E0)

Answer 17

• measures tendency of a donor of a half rxn to lose electrons
• conjugate redox pairs with more negative E0 will donate to pairs with a more + E0!
• this will release energy, which can be used to produce ATP