Chapter 13 - Chemoorganotrophy

Question 1

Chemoorganotrophy

Answer 1

Term used to denote the oxidation of organic chemicals to yield energy. Can be performed in presence of O2 or absence.

Question 2

Aerobic Respiration

Answer 2

When the process utilizes gylcolysis and Tricarboxylic acid cycle to completely oxidize an organic compound down to Co2 - Presence of O2 - O2 Final electron acceptor

Question 3

ATP Generation

Answer 3

This is where most ATP is generated, given large amount of distance between initial donor (glucose) and final acceptor (Oxygen), as well as large number of electrons glucose can donate

Question 4

Glycolysis

Answer 4

Universal pathway for catabolism of glucose to pyruvate.

Question 5

Glycolysis Part I

Answer 5

Modifications to the 6-carbon sugar glucose. Requires two molecules of ATP to phosphorylate (activate) the sugar.

Question 6

Glycolysis Part II

Answer 6

6-carbon sugar split into two 3 carbon molecules, yielding a bifuricated pathway. 4 Molecules or ATP are generated by substrate-level phosphorylation

Question 7

Net yield of Energy from Glycolysis?

Answer 7

2 Molecules of ATP for every 1 molecule of Glucose - Also 2 molecules of carrier NAD+ are reduced, forming NADH. Also 2 molecules of the 3-carbon pyruvate are produced.

Question 8

Tricarboxylic Acid Cyle (TCA)

Answer 8

Picks up at end of glycolysis and oxidizes each pyruvate to 3 molecules of CO2.

Question 9

TCA Part I

Answer 9

Connecting reaction that leads to reducing 1 molecule of NAD+ to NADH - making citrate

Question 10

TCA Part II

Answer 10

Citrate then enters into the actual cycle and undergoes series of oxidations yielding products. As electrons are released, carriers are reduced, yielding 3 molecules of NADH and 1 Molecule of FADH for every molecule of pyruvate. Also 1 molecule of GTP generated.

Question 11

Net Yield of TCA Cycle

Answer 11

2 molecules of GTP, 8 molecules of NADH, 2 molecules of FADH.

Question 12

Oxidative Phosphorylation

Answer 12

Synthesis of ATP from electron transport generated from oxidizing a chemical energy source

Question 13

Proton Motive Force

Answer 13

Protons not accepted by carriers move outward and line outer part of membrane. This explains negatively charged membrane! As they accumulate, concentration gradient develops. Becomes more alkaline and negative, leading to chemical and electrical difference. Can then be used for work of the cell (flagellum)

Question 14

ATP Synthase

Answer 14

Used during PMF to synthesize ATP. Large enzymes w/ two components - one that spans membrane and one that sticks into cytoplasm. Protons driven through spanning, generating torque that rotates cytoplasm part. When it returns to original formation, it binds Pi to ADP, generating ATP

Question 15

Anaerobic Chemoorganotrophy

Answer 15

No Oxygen present and a different electron acceptor must be used.

Question 16

Anaerobic Respiration

Answer 16

starts with glycolysis and the pyruvate is sent to TCA cycle. Oxidative phophorylation generates much of the ATP utilizing ETC and ATP synthase. Key difference is that final acceptor is not O2.

Question 17

Which acceptor is used for Anaerobic respiration?

Answer 17

The best is one that will be lowest down on the electron tower in oxidized form (left side). Commons are No3-, FE3+, SO42- CO32-

Question 18

ATP generated during Anaerobic Respiration?

Answer 18

Not as much as aerobic and depends on acceptor used.

Question 19

Fermentation

Answer 19

Catabolism of glucose in the absence of oxygen. Does not use O2 as final acceptor, but instead uses pyruvate as final to generate a variety of products. Does not have an ETC

Question 20

Fermentation Part 1

Answer 20

Glycolysis - yielding 2 ATP by substrate level phosphorylation and 2 molecules of NADH.