Ch.5: Microbial Metabolism

Question 1

Metabolism

Answer 1

The sum of all chemical reactions in a cell

Question 2

Catabolism

Answer 2

• the breakdown of complex organic compounds into simpler ones
• are called catabolic or degradative reactions
• Break bonds and release energy

Question 3

Anabolism

Answer 3

• the building of complex organic molecules from simpler ones
• called anabolic or biosynthetic reaction
• Making bonds, energy is used/absorbed

Question 4

Diversity in prokaryotes are in their _______.

Answer 4

Chemistry (metabolism)

Question 5

Possible carbon sources for prokaryotes

Answer 5

• Organic Carbon (hetero)
• Inorganic Carbon (auto) ​in the form of CO2

Question 6

Possible energy sources for prokaryotes

Answer 6

• Sunlight (photo)
• Chemical compounds (chemo)
  
  • organic compounds (organo)
    
    • sugars, amino acids, etc.
  • inorganic chemical (litho)
    
    • H2, NH3, NO2-, Fe2+, H2S

Question 7

Photoautotroph

Answer 7

• Energy: Sunlight (photo)
• Carbon Source: Carbon Dioxide (auto)

Question 8

Photoheterotroph

Answer 8

• Energy: Sunlight (photo)
• Carbon Source: Organics (hetero)

Question 9

Chemolithoautotroph

Answer 9

• Energy: Inorganic Chemicals (litho)
• Carbon Source: Carbon Dioxide (auto)

Question 10

Chemoorganoheterotroph

Answer 10

• Energy: Organic compounds (organo)
• Carbon Source: Organics (hetero)

Question 11

ATP

Answer 11

• Energy currency of the cell
• Adenine triphosphate
  
  • 3 phosphate groups
  • Ribose sugar
  • Adenine nitrogenous base

Question 12

​ATP Hydrolysis

Answer 12

• Leads to ADP - Adenine diphosphate
  
  • Ribose
  • Adenine nitrogenous base
  • 2 phosphate groups

Question 13

Most enzymes are large _____ molecules

Answer 13

Protein

Question 14

Location where the substrate binds to the enzyme

Answer 14

ACTIVE SITE

Question 15

When a molecule loses an electron, it is ________

Answer 15

Oxidized

• L.E.O
  
  • ​​Lose
  • Electron
  • Oxidized

Question 16

When a molecule gains an electron, it is _______

Answer 16

Reduced

• G.E.R
  
  • ​​Gain
  • Electron
  • Reduced

Question 17

NAD+/FAD (vitamins)

Answer 17

• Nicotinamide Adenine Dinucleotide & Flavin adenine dinucleotide
  
  • Oxidized forms
  • Electron Acceptors

Question 18

NADH/FADH2

Answer 18

• Reduced forms
• Electron donor

Question 19

​Aerobic Cellular Respiration

Answer 19

C6H12O6 + O2 ——> CO2 + H20 + ATP

• Terminal electron acceptor is O2
• the product is water
• Generates roughly 38 ATP (34 from ETC, 2 from glycolysis, 2 from Krebs Cycle)

Question 20

Steps to Aerobic Cellular Respiration

Answer 20

1. Glycolysis
2. Pyruvate Oxidation
3. Kreb’s Cycle/Citric Acid Cycle/ TCA Cycle
4. Oxidative Phosphorylation (ETC/ATP Synthase)

Question 21

Metabolic Pathways

Answer 21

• A sequence of chemical reactions in a cell
• Determined by enzymes

Question 22

1). Glycolysis (anaerobic)

Investment Step

Answer 22

• Glucose (6-carbon sugar) conversion to 2 Pyruvate (3-carbon sugar)
• Inputs:
  
  • 1 glucose
  • net 2 ADP
  • 2 NAD+
• Outputs:
  
  • net 2 ATP
  • 2 NADH
  • 2 Pyruvate
• Occurs in cytoplasm in both Euk/Pro

Question 23

Kinase

Answer 23

• Enzyme that transfers phosphates
• Hexokinase: glucose + ATP —-> glucose-6-phosphate + ADP
• Pyruvate Kinase: PEP + ADP —> ATP + Pyruvate

Question 24

Substrate Level Phosphorylation

Answer 24

moving a phosphate from a substrate directly to ADP to make ATP; requires an enzyme (kinase)

Question 25

2). Pyruvate Oxidation (anaerobic)

Transition Step

Answer 25

• Used in aerobic and anaerobic respiration
• generates 2 NADH and 2 Acetyl CoA
• CoA = coenzyme A (small organic vitamin cofactor)
• 2 CO2 is also made
• Eukaryotic
  
  • Mitochondria
• Prokaryotic
  
  • Cytoplasm

Question 26

3). Krebs Cycle

Answer 26

• Used in aerobic and anaerobic respiration
• Generates 2 ATP, 6 NADH, 2 FADH2
  
  • ​​2 Cycles per glucose molecule
  • Lots of NADH generated
• Release 4 CO2
• Eukaryotic
  
  • Mitochondria
• Prokaryotic
  
  • Cytoplasm

Question 27

4). Oxidative Phosphorylation (Electron Transport Chain/ATP Synthase/Chemiosmosis)

Aerobic

Answer 27

• Series of molecules in a membrane that transports electrons
• 1 NADH = 3 ATP ——– 10 NADH = 30 ATP
• 1 FADH2 = 2 ATP ——– 2 FADH2 = 4 ATP
• 34 ATP made
• oxygen (terminal electron acceptor)
• A cell always has an ETC
  
  • allows flagella to rotate
  • also used for the transport of molecules
• Eukaryotic
  
  • Inner membrane of mitochondria
• Prokaryotic
  
  • Across cytoplasmic membrane

Question 28

NADH Dehydrogenase

Answer 28

• 1st protein enzyme of the ETC
• catalyzes NADH —> NAD+

Question 29

​Quinones

Answer 29

• are hydrophobic non-protein molecules that accept both electrons and protons, but only pass on electrons

Question 30

​Proton Motive Force

Answer 30

• Charge gradient/electrochemical gradient/proton gradient

Question 31

Anaerobic Respiration

Answer 31

• Difference is the terminal electron acceptor
  
  • NO3- (nitrate) and SO4-2 (sulfate)
    
    • NO2- (nitrite) and H2S (hydrogen sulfide) are reduced forms of nitrate/sulfate
• less ATP produced

Question 32

Fermentation

Answer 32

• Anaerobic Respiration
• far less ATP made (2 ATP)
• Pyruvate gets reduced
  
  • Pyruvate Reduction
    
    • produces alcohol and CO2
    • Acid compounds
      
      • Depends on enzyme used
• Terminal Electron acceptor is pyruvate