Q: Which of the following is the correct summary equation for oxygenic photosynthesis?

$$6 \text{CO}_2 + 12 \text{H}_2\text{O} + \text{light energy} \rightarrow \text{C}_6\text{H}_{12}\text{O}_6 + 6 \text{O}_2 + 6 \text{H}_2\text{O}$$

Question 1

Which of the following best describes a chemoorganoheterotroph?

Accepted Answer

Uses organic molecules as a carbon source, organic molecules as an energy source, and organic molecules as an electron source.

Question 2

During aerobic respiration in prokaryotes, what is the theoretical maximum yield of ATP per molecule of glucose?

Accepted Answer

$$38$$

Question 3

Which process does NOT require an electron transport chain?

Accepted Answer

Fermentation

Question 4

In the Embden-Meyerhof pathway (glycolysis), what is the net ATP yield per molecule of glucose?

Accepted Answer

$$2$$ ATP

Question 5

Which of the following is the correct sequence of electron flow in the mitochondrial electron transport chain during aerobic respiration?

Accepted Answer

NADH $$\rightarrow$$ Complex I $$\rightarrow$$ CoQ $$\rightarrow$$ Complex III $$\rightarrow$$ Cytochrome c $$\rightarrow$$ Complex IV $$\rightarrow O$_2$$

Question 6

Which of the following is a distinguishing feature of anoxygenic photosynthesis?

Accepted Answer

It uses only one photosystem and does not produce O$$_2.$$

Question 7

What is the main function of the proton motive force (PMF) generated during electron transport?

Accepted Answer

To drive the synthesis of ATP via ATP synthase

Question 8

Which of the following is the final electron acceptor in methanogenesis?

Accepted Answer

CO$$_2$$

Question 9

Which of the following statements about substrate-level phosphorylation is TRUE?

Accepted Answer

It involves the direct transfer of a phosphate group from a high-energy intermediate to ADP.

Question 10

A bacterium that uses ammonia (NH$$_3) as an $$energy source, CO$$_2 as a $$carbon source, and inorganic molecules as an electron source is best classified as:

Accepted Answer

Chemolithoautotroph

Question 11

Which of the following is a key difference between aerobic and anaerobic respiration?

Accepted Answer

Aerobic respiration uses O$$_2 as $$the final electron acceptor, while anaerobic respiration uses other molecules such as NO$$_3^- or SO$_4$$^{2-}$$.

Question 12

Which of the following best explains why fermentation yields less ATP than respiration?

Accepted Answer

Fermentation uses only substrate-level phosphorylation and does not utilize an electron transport chain.

Question 13

Which of the following is a product of the citric acid cycle (Krebs cycle) for each acetyl-CoA oxidized?

Accepted Answer

3 NADH, 1 FADH$$_2$$, 1 GTP, 2 CO$$_2$$

Question 14

Which of the following is the correct summary equation for oxygenic photosynthesis?

Accepted Answer

$$6 	ext{CO}_2 + 12 	ext{H}_2	ext{O} + 	ext{light energy} ightarrow 	ext{C}_6	ext{H}_{12}	ext{O}_6 + 6 	ext{O}_2 + 6 	ext{H}_2	ext{O}$$

Question 15

Which of the following is a common electron acceptor in anaerobic respiration by soil bacteria?

Accepted Answer

NO$$_3^-$$

Question 16

Which pathway is unique to some soil bacteria and produces 1 ATP, 1 NADH, and 1 NADPH per glucose molecule?

Accepted Answer

Entner-Doudoroff pathway

Question 17

Which of the following is a direct result of denitrification in the nitrogen cycle?

Accepted Answer

Conversion of nitrate (NO$$_3^-) to $$nitrogen gas (N$$_2)$$

Question 18

Which of the following best describes the role of reverse electron flow in chemolithoautotrophs?

Accepted Answer

It is used to generate NAD(P)H for CO$$_2$$ fixation when the electron donor has a more positive redox potential than NAD(P)H.

Question 19

Which of the following is a consequence of the lower energy yield from chemolithotrophy compared to glucose oxidation?

Accepted Answer

Chemolithotrophs grow more slowly due to less ATP production.

Microbial Energy Metabolism: Chemotrophy and Phototrophy

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