Microbiology (Tortora), Chapter 5

Front 1

Metabolism (def.)

Back 1

Sum of all chemical reactions within a living organism.

Front 2

Catabolism (def.)

Back 2

Breakdown of complex organic compounds into simpler ones.
Exergonic (produce energy).

Front 3

Anabolism (def.)

Back 3

Building of complex organic molecules from simpler ones.
Endergonic (require energy).

Front 4

Redox Reaction (def.)

Back 4

Reduction (gain e-) coupled with oxidation (lose e-).

Front 5

Redox Reaction : NAD and FAD

Back 5

Common electron carrier.
NAD+ + H2 --> NADH + H+
FAD + H2 --> FADH2

Front 6

ATP (func.)

Back 6

Used to couple reactions (provide energy for endothermic reactions)

Front 7

Metabolic Diversity

Back 7

Autotrophs (self-feeders)
Heterotrophs (feeders on others)

Hint 7

"-trophs"

Front 8

Autotrophs (2)

Back 8

Photoautotrophs - use light as a source of energy and CO2 as source of carbon.
Chemoautotrophs - use inorganic compounds for energy.

Front 9

Heterotrophs (2)

Back 9

Photoheterotrophs - use light energy to use organic compounds.
Chemoheterotrophs - use energy from organic compounds directly.

Front 10

Uses of Energy (3)

Back 10

Biosynthesis - prod. of chemicals through a series of reactions.
Movement - cell movement, internal movement, membrane transport.
Bioluminescence - glowing.

Front 11

Enzymes (def.)

Back 11

Catalysts that speed up reactions by lowering their activation energy.

Front 12

Enzyme Requirements

Back 12

Reactions must be spontaneous.
Each enzyme binds to a specific substrate.
Enzymes are reused.

Front 13

Enzyme Function

Back 13

E + S --> ES --> EP --> E + P

Front 14

Mechanism of Enzymatic Action (4 steps)

Back 14

Substrate binds to active side of enzyme.
Temporary intermediate compound forms, enzyme-substrate complex.
Substrate molecule is transformed.
Enzyme releases products.

Front 15

Enzyme Regulation

Back 15

Environment (temperature, pH, substrate concentration)
Activation (coenzymes - organic, e.g. vitamins; cofactors - inorganic, e.g. minerals)
Inhibition (competitive, noncompetitive regulation, feedback inhibition)

Front 16

Competitive Inhibition (def.)

Back 16

Inhibitor binds to active site of enzyme.

Front 17

Non-competitive Regulation or Allosteric Inhibition (def.)

Back 17

Inhibitor binds to another (allosteric) site on enzyme, preventing substrate from binding to active site.

Front 18

Feedback Inhibition (def.)

Back 18

Allosteric inhibitor inhibits the activity of the first enzyme in the pathway.

Front 19

Cellular Respiration (def.)

Back 19

An ATP-generating process in which molecules are oxidized and the final electron acceptor is (almost always) an inorganic molecule.

Front 20

Types of Respiration (2)

Back 20

Aerobe (requires oxygen)
Anaerobe (no oxygen required)

Front 21

Cellular Respiration : Coenzymes (2)

Back 21

NAD
FAD

Front 22

Cellular Respiration : Steps (4)

Back 22

Glycolysis
Acetyl-CoA formation
Krebs Cycle
Electron Transport System

Front 23

Cellular Respiration : Reaction

Back 23

C6H12O6 + 6 O2 + 38 ADP --> 6 CO2 + 6 H2O + 38 ATP

Front 24

Glycolysis (process)

Back 24

"Splitting of sugar"
Glucose (1 x C6) --> pyruvic acid (2 x C3)
10-step process
Requires 2 ATP, produces 4 ATP (net gain: 2 ATP for each oxidized glucose molecule)

Front 25

Acetyl-CoA Formation

Back 25

Yields 2 NADH (1 per pyruvate)
Pyruvate + CoA --> CO2 + Acetyl-CoA

Front 26

Krebs Cycle

Back 26

Yield: 2 ATP, 6 NADH, 2 FADH2
C4 (oxaloacetate) + Acetyl-CoA --> citrate (C6) + CoA
C6 --> C5 --> C4 yielding 2 CO2 + energy

Front 27

Electron Transport and Chemiosmosis

Back 27

Occurs on membrane
Converts energy carried by NADH and FADH2 to ATP (3/NAD, 2/FAD)

Front 28

Chemiosmosis

Back 28

Production of ATP by a proton (H+) gradient.
Protons have been pumped into inner/outer membrane space. High concentration drives movement of protons back across membrane.
ATP synthase: force of proton movement powers ATP synthesis
Electrons accepted by various molecules.

Front 29

Cellular Respiration : Balance Sheet (Total # of ATP produced)

Back 29

38 ATP (34 from 10 NAD and 2 FAD)

Front 30

Fermentation (def.)

Back 30

A "shortcut" respiration process.
Regenerates NAD+ to run glycolysis. This produces ATP by substrate level phosphorylation only.
Inefficient, but very fast and no O2 required.

Front 31

Types of Fermentation (2)

Back 31

Alcohol fermentation - by yeast; ethanol and CO2 produced.
Lactic acid fermentation - by humans; lactic acid produced.

Front 32

Lipid and Protein Catabolism

Back 32

Fats and proteins enter in different places of respiration.
Triacylglycerol is broken down to fatty acid and glycerol.
Proteins are broken down into amino acids and deaminated

Front 33

Photosynthesis (formula)

Back 33

6 CO2 + 6 H2O + energy --> C6H12O6 + O2

Front 34

Photosynthesis : Types of Reactions (2)

Back 34

Light-dependent
Light-independent

Front 35

Light-dependent Photosynthesis

Back 35

Makes ATP and NADPH using light.
Cyclic photophosphorylation makes only ATP and recycles electron.
Noncyclic makes both ATP and NADPH. Electron goes to NADPH.

Front 36

Light-independent Photosynthesis

Back 36

Calvin cycle - 3 CO2 in, 1 C3 out per turn; 9 ATP used.