Chapter 13

Question 1

Ability to do work

Answer 1

energy

Question 2

Absorb light and convert it to chemical energy

Answer 2

phototrophy

Question 3

light energy is used to photolyse a reduced compound other than water. An example is H2S

Answer 3

Anoxygenic

Question 4

Light energy is used to photolyse: H20 releasing oxygen

Answer 4

oxygenic

Question 5

Catabolism of high energy compound to a lower energy product through a series of oxidation reduction reactions

Answer 5

chemotrophy

Question 6

The oxidization of inorganic chemicals. An example would be nitrifying bacteria

Answer 6

Lithotroph

Question 7

Examples of inorganic chemicals that lithotrophs use

Answer 7

H2, H2S, NH4+, Fe2+

Question 8

Oxidize organic compounds (sugars)

Answer 8

Organotroph

Question 9

The reaction will proceed in the forward direction, releasing energy

Answer 9

Gibbs free energy is negative

Question 10

Disorder. The universe tends
toward a state of disorder, therefore a
reaction creating disorder would be
favorable.

Answer 10

Entropy

Question 11

Is heat absorbed or
released by the reaction?

Answer 11

Enthalpy

Question 12

What does a negative delta H mean?

Answer 12

Heat is released by the reaction. This occurs because the
reactants were less stable than the product.

Question 13

What does a positive Delta H mean?

Answer 13

Heat is absorbed during the
reaction, this would indicate that
the products are less stable than
the reactants.

Question 14

What does a negative delta S mean?

Answer 14

The products have more order than
the reactants.

Question 15

What does a positive delta S mean?

Answer 15

The products have less order than
the reactants. Disorder was created.

Question 16

What are the three factors that can influence delta G?

Answer 16

1. Changes in enthalpy and entropy
2. Concentration of products and reactants
3. Environmental factors

Question 17

What is the equation for Aerobic Respiration?

Answer 17

C6H12O6 + 6O2 = 6 CO2 + 6 H2O

Question 18

What energy carriers are used during aerobic respiration?

Answer 18

1. ATP
2. NADH
3. FADH2

Question 19

Molecules that gain or release small amounts of
energy in reversible reactions

Answer 19

energy carriers

Question 20

What are the three ways that ATP can deliver energy to the cell?

Answer 20

1. Hydrolysis-releasing phosphate (Pi)
2. Hydrolysis-releasing pyrophosphate (PPi)
3. Phosphorylation of an organic molecule

Question 21

A reducing agent

Answer 21

electron donor

Question 22

oxidizing agent

Answer 22

electron acceptor

Question 23

Where does glycolysis happen?

Answer 23

In the cytoplasm

Question 24

During glycolysis how many ATP molecules are used and how many are gained?

Answer 24

2 ATP molecules go into glycolysis to start it and 4 ATP molecules are produced

Question 25

What happens with NAD+ and NADH in glycolysis?

Answer 25

In glycolysis, 2 NAD+ molecules are reduced into 2 NADH molecules which carry these electrons to the ETC

Question 26

electron carrier (dump truck) that goes back and forth. between glycolysis and the ETC

Answer 26

NAD+

Question 27

lower the activation energy required for a reaction to occur

Answer 27

enzymes

Question 28

catalyzes transfer of a phosphate group → produces pyruvate and ATP

Answer 28

pyruvate kinase

Question 29

What are the substrates that microbes help catalyze

Answer 29

1. Polysaccharides 2. Pyruvate and other intermediary products of sugar catabolism 3. Lipids and amino acids 4. aromatic compounds

Question 30

are broken down to disaccharides, and then to monosaccharides; sugar and sugar derivatives, such as amines and acids, are catabolized to pyruvate.

Answer 30

Polysaccharides

Question 31

are fermented or further catabolized to CO2 and H2O via the TCA cycle.

Answer 31

Pyruvate and other intermediary products of sugar catabolism

Question 32

are catabolized to glycerol and acetate, as well as other metabolic intermediates.

Answer 32

Lipids and amino acids

Question 33

are catabolized to acetate through different pathways such as the catechol pathway.

Answer 33

aromatic compounds

Question 34

What are the two models of metabolism?

Answer 34

1. Fermentation 2. Respiration

Question 35

Partial breakdown of organic food without net electron transfer to an inorganic terminal electron acceptor

Answer 35

Fermentation

Question 36

complete breakdown of organic molecules with electron transfer to a terminal electron acceptor such as O2

Answer 36

Respiration

Question 37

What are the three ways that bacteria and archea break down glucose

Answer 37

1. Embden-Meyerhof- Parnas (EMP) 2. Entner-Doudoroff (ED) 3. Pentose Phosphate Pathway

Question 38

Most common method of glucose metabolism Energy investment stage followed by energy extraction Occurs in the cytoplasm Can occur in the presence or absence of oxygen

Answer 38

EMP pathway

Question 39

For each glucose molecule, the EMP pathway produces

Answer 39

2 net ATP (4 total) 2 NADH + H+ 2 Pyruvate

Question 40

Used by some gram-negative bacteria

Answer 40

Entner-Doudoroff pathway

Question 41

What are the products of the Entner-Doudoroff pathway?

Answer 41

1 ATP 1 NADPH 1 NADH

Question 42

Generates NADPH Generates ATP by shuttling intermediates to the EMP pathway Generates a 5-carbon intermediate (Ribulose-5-P) which can be used for building or rearranging to make carbon skeletons containing 3-7 carbons.

Answer 42

Pentose Phosphate Pathway

Question 43

In prokaryotes, it occurs in the cytoplasm. In eukaryotes, it occurs in the mitochondria.

Answer 43

The Tricarboxylic Acid Cycle (AKA Krebs cycle akaaka citric cycle)

Question 44

Glucose catabolism connects with the TCA cycle through

Answer 44

pyruvate breakdown to acetyl-CoA and CO2.

Question 45

Conversion of pyruvate to acetyl-CoA is catalyzed by a very large multisubunit enzyme called the

Answer 45

pyruvate dehydrogenase complex (PDC).

Question 46

For each pyruvate oxidized:

Answer 46

3 CO2 are produced by decarboxylation. 4 NADH and 1 FADH2 are produced by redox reactions. 1 ATP is produced by substrate-level phosphorylation.

Question 47

The overall process of electron transport and ATP generation is termed

Answer 47

oxidative phosphorylation.

Question 48

What organisms are primarily responsible for the catabolism of aromatic molecules in ecosystems?

Answer 48

bacteria and fungi

Question 49

Why is the catabolism of aromatic molecules by microbes important in ecosystems?

Answer 49

It recycles important substances and helps degrade toxic pollutants.

Question 50

What is benzoate catabolized into during aerobic degradation?

Answer 50

catechol

Question 51

What happens to catechols after they are formed from benzoate?

Answer 51

They are degraded through several alternative pathways to the TCA cycle.

Question 52

How do bacteria and fungi contribute to pollution control?

Answer 52

By degrading toxic aromatic pollutants like benzoate through aerobic catabolism.

Question 53

What is a key intermediate formed from the degradation of aromatic compounds like benzoate and nitrobenzene?

Answer 53

catechol

Question 54

What enzyme converts benzoate into catechol?

Answer 54

Benzoate dioxygenase.

Question 55

What metabolic cycle do the end products of catechol degradation enter?

Answer 55

The TCA (tricarboxylic acid) cycle.

Question 56

What role do microbes play in oil spill cleanup?

Answer 56

Microbes naturally degrade hydrocarbons in oil spills, reducing pollutant concentrations through biodegradation.

Question 57

What are aromatic pollutants?

Answer 57

Toxic, carbon-rich molecules with stable ring structures that can be degraded by microbial catabolism.

Question 58

What pathway does benzoate follow under aerobic conditions?

Answer 58

Benzoate is oxidized to catechol via benzoate dioxygenase.

Question 59

A central intermediate in the aerobic degradation of aromatic compounds.

Answer 59

catechol

Question 60

What two enzymes degrade catechol?

Answer 60

Catechol 1,2-dioxygenase Catechol 2,3-dioxygenase

Question 61

What are the final products of catechol degradation?

Answer 61

Acetyl-CoA, Succinyl-CoA, pyruvate, and acetaldehyde, which enter the TCA cycle.

Question 62

What happens to benzoate under anaerobic conditions?

Answer 62

It undergoes reductive degradation after being activated by acetyl-CoA.

Question 63

Why is anaerobic degradation slower than aerobic degradation?

Answer 63

Because it lacks oxygen as an electron acceptor, requiring alternative, less efficient pathways.

Question 64

known to be important and regulating anxiety and depression

Answer 64

GABA

Question 65

affects the immune response

Answer 65

Histamine

Question 66

What are SCFAs and how are they produced?

Answer 66

short-chain fatty acids produced through microbial fermentation of dietary fibers.

Question 67

What are some effects of SCFAs on the human host?

Answer 67

SCFAs influence metabolism, inflammation, gut health, and immune function.