Chapter 5- Microbial Metabolism

Question 1

Metabolism

Answer 1

The sum of all chemical reactions within a living organism

Question 2

Metabolism is divided into two types of chemical reactions:

What’s the difference between these two?

Answer 2

Catabolic: breaks down large molecules into smaller products, exergonic (releases energy), ex: proteins –> a.a

Anabolic: turns smaller products into large molecules, requires energy to make bonds (endergonic), ex: a.a—> protein or fatty acid –> lipid

Question 3

Is this anabolic or catabolic:

Starch (a polymer) is built from simple sugars (monomers)

Answer 3

Anabolic

Question 4

Energy coupling

Answer 4

The energy that is released from the catabolic reactions can be used to drive an anabolic reaction that requires energy

Question 5

Metabolic reactions usually involve the movement of electrons (which are ________ of _____). The molecule that is oxidized is the one to _____ the electron and involves _____. The molecule that is reduced ______ the electron and involves _____.

Answer 5

carriers of energy

oxidized: donates the electron and involves loss (OIL)
reduced: accepts the electron and involves gain (RIG)

Question 6

To move the electrons around (for oxidation-reduction reactions), a carrier is often used. The important ones are:

The electron is usually associated with a _______ atom since it only has _____ ______. So the carriers pick up and drop off the _____.

Answer 6

NAD+
NADP+
FAD

The electron is usually associated with a HYDROGEN atom since it only has ONE ELECTRON. So the carriers pick up and drop off the HYDROGENS.

Question 7

ATP is responsible for

Answer 7

mediating or carrying out energy coupling in cells

Question 8

ATP is composed of

Answer 8

3 phosphorus groups
a sugar (ribose)
and a nitrogenous base (adenine)

Question 9

How does ATP produce energy?

Answer 9

The terminal phosphate bond gets broken (just one out of the three)

Question 10

When the _____ _____ bond is broken, the terminal phosphate ____ is ___ from ATP. We call this terminal phosphate _____ an _____ ________, abbreviated as ____.

Answer 10

When the TERMINAL PHOSPHATE BOND is broken, the terminal phosphate GROUP is REMOVED from ATP. We call this terminal phosphate GROUP an INORGANIC PHOSPHATE, abbreviated as Pi.

Question 11

After the removal of the terminal phosphate group, ATP becomes _____ and ______ __ ____

Answer 11

ADP

energy is released

Question 12

Phosphorylation

Answer 12

When ATP is regenerated/recycled from ADP and Pi (inorganic phosphate)

Question 13

3 ways phosphorylation can be accomplished:
(basically, who provides the energy for the third phosphorus? ADP + P —> ATP

Answer 13

Substrate-level phosphorylation
Oxidative phosphorylation
Photophosphorylation

Question 14

Substrate-level phosphorylation

Answer 14

transfers Pi from an organic molecule

(the bond gets broken)

Question 15

Oxidative phosphorylation

Answer 15

Using energy from the redox reaction to add Pi
(there’s no bond to be broken)

Question 16

Photophosphorylation

Answer 16

Using light energy to add Pi
(no bond broken)

Question 17

ATP has ___ phosphate while ADP has ___

Answer 17

3

2

Question 18

Enzymes

Answer 18

Speeds up chemical reactions by lowering the amount of activation energy needed

Requires energy

Question 19

The amount of energy required by the reactant molecules for bond breaking is known as the

Answer 19

activation energy

Question 20

Each enzyme can only bind to its own ____ ___ (they’re _____-______). The specificity of an enzyme is due to its _____ ___ ____.

Answer 20

Each enzyme can only bind to its own SPECIFIC SUBSTRATE (substrate-specific). The specificity of an enzyme is due to its UNIQUE 3D SHAPE.

Question 21

What’s an active site?

Answer 21

the specific shape of the substrate (that matches with the specific shape of the enzyme)

Question 22

Apoenzyme

Answer 22

The name of the protein portion when the enzyme is combined with other molecules

Question 23

The apoenzyme is ____ if not bound to nonprotein ______

Answer 23

inactive
cofactors

Question 24

Cofactors are ____ molecules, like ___ or ___. If the cofactor is an ______ molecule, it’s called a _____.

Answer 24

Cofactors are INORGANIC molecules, like Zn or Fe. If the cofactor is an ORGANIC molecule, it’s called a COENZYME

Question 25

Important coenzymes:

Answer 25

NAD FAD CoA

Question 26

Holoenzyme

Answer 26

Yields from when apoenzyme binds with its cofactors/coenzymes

Question 27

Factors that influence the activity/action of an enzyme:

Answer 27

Temperature pH Substrate concentration Inhibitors

Question 28

If the temperature goes up too high, the rate of the reactions slows down as enzymes get _____. Enzymes are most active in ____ temperatures

Answer 28

denatured warmer

Question 29

Competitive inhibitors

Answer 29

bind to an active site

Question 30

Noncompetitive inhibitors

Answer 30

binds to an allosteric site, distorting the active site (so it no longer matches with the enzyme)

Question 31

Energy production is due to the

Answer 31

movement of electrons

Question 32

Most microorganisms tend to break down carbohydrates to obtain their energy- specifically ____

Answer 32

Glucose

Question 33

2 main pathways of energy production

Answer 33

cellular respiration fermentation

Question 34

The overall process of cellular respiration can be summarized as

Answer 34

Glycolysis Krebs Cycle Electron Transport Chain

Question 35

General equation for cellular respiration: Which is being oxidized and which is being reduced? Why?

Answer 35

C6H12O6 + 6O2 ----> 6CO2 + 6H2O + ATP C6H12O6 is oxidized because the hydrogens are taken away and become 6CO2 6O2 is reduced because hydrogens are gained: 6H2O

Question 36

Cellular respiration is a _____ reaction because ____________. All of the energy comes from the _____ ____

Answer 36

catabolic energy gets released glucose molecule

Question 37

Glycolysis starting molecule: ending molecule:

Answer 37

starting: Glucose ending: Pyruvic Acid

Question 38

What carrier molecule is used during Glycolysis and how many?

Answer 38

NADH, 2

Question 39

How much ATP is used in Glycolysis? How much is produced? Net amount?

Answer 39

2 ATP is used 4 ATP is produce, 2 net

Question 40

Penicillium is a ____ that leads to antibiotics Streptomyces is a _____ that leads to antibiotics

Answer 40

mold bacteria

Question 41

Only ____ leads to fermentation, not ____

Answer 41

yeast, not bacteria

Question 42

Tetrapeptide cross bridges hold together..

Answer 42

NAM and NAM molecules

Question 43

Outer cell/cytoplasmic membranes are made up of a cholesterol-like molecule called a

Answer 43

Hopanoid

Question 44

Each molecule of pyruvate coming from glycolysis must first be converted to another chemical called_______

Answer 44

acetyl coenzyme A (acetyl CoA)

Question 45

The preparation stage

Answer 45

2 NADH 2 CO2 2 acetyl CoA

Question 46

2 points about the Krebs Cycle

Answer 46

It occurs in the cytoplasm of prokaryotes A great amount of energy remains in the bonds of acetyl CoA

Question 47

Key concepts of the Krebs Cycle: Starting molecule? How many molecules of ATP? What method of phosphorylation? How many molecules of FADH2? How many molecules of NADH? How many molecules of CO2?

Answer 47

Starting molecule? Acetyl-CoA How many molecules of ATP? 2 What method of phosphorylation? Substrate level phosphorylation How many molecules of FADH2? 2 How many molecules of NADH? 6 How many molecules of CO2? 4

Question 48

The Electron Transport Chain is the most _____ ____ in aerobic respiration because it will generate the most number of ____ ___

Answer 48

important stage ATP molecules

Question 49

The Electron Transport Chain: During aerobic respiration, there is a lot of transferring of electrons (aka oxidation-reduction reactions) going on. Glucose _____ its electrons to form ____. This reaction is called ______. Oxygen ____ the electrons given away from glucose to form ____. This is called a ______.

Answer 49

During aerobic respiration, there is a lot of transferring of electrons (aka oxidation-reduction reactions) going on. Glucose LOSES its electrons to form CO2. This reaction is called OXIDATION. Oxygen GAINS the electrons given away from glucose to form WATER. This is called a REDUCTION.

Question 50

Electron Transport Chain: -There is a series of _____ ____ that pass electrons from one to another to a _____ ____ ____ -Energy from electrons used to pump protons (H+) across the membrane, establishing a ______ ______. These protons return through a channel protein attached to the enzyme ___ ____ - Occurs in the ___ ____ of ______

Answer 50

Electron Transport Chain: -There is a series of CARRIER MOLECULES that pass electrons from one to another to a FINAL ELECTRON ACCEPTOR -Energy from electrons is used to pump protons (H+) across the membrane, establishing a CONCENTRATION GRADIENT. These protons return through a channel protein attached to the enzyme ATP SYNTHASE - Occurs in the CELL MEMBRANE of PROKARYOTES

Question 51

In aerobic respiration, ____ is the final electron acceptor. In anaerobic respiration, it's an ______ _____ that acts as the final electron acceptor

Answer 51

Oxygen Inorganic molecule

Question 52

What method of phosphorylation occurs in the Electron Transport Chain?

Answer 52

Oxidative phosphorylation

Question 53

Electron Transport Chain: Each NADH creates __ __ Each FADH creates __ __ In total, there are ___ ATP molecules that can be generated from one ____ ____

Answer 53

3 ATP 2 ATP 34 ATP glucose molecule

Question 54

Summary of Metabolic Stages: Glycolysis:_______---> ______ The Preparation stage: _____---> ______ The Krebs Cycle: _______---> ______ The Electron Transport Chain: once ______ _____ electrons, it is _____ to form ____

Answer 54

Glycolysis: 1 glucose molecule --> 2 pyruvate molecules The Preparation stage: each pyruvate molecule---> acetyl CoA molecule The Krebs Cycle: each acetyl CoA ---> CO2 The Electron Transport Chain: once oxygen accepts electrons, it is reduced to form H20

Question 55

Summary of Energy Yielded: Glycolysis: The Preparation Stage: The Krebs Cycle: The Electron Transport Chain: Total:

Answer 55

Glycolysis: 2 ATP, 2 NADH The Preparation Stage: 2 NADH The Krebs Cycle: 2 ATP, 2 FADH2, 6 NADH The Electron Transport Chain: 34 ATP Total: 38 ATP molecules per glucose molecule

Question 56

In anaerobic respiration, some commonly used inorganic molecules (that act as final electron acceptors) are..

Answer 56

Sulfate and Nitrate

Question 57

In anaerboic respiration, what's the ATP yield?

Answer 57

between 2 and 36 ATP molecules

Question 58

End products of fermentation

Answer 58

Lactic acid and ethanol

Question 59

How much ATP does fermentation produce?

Answer 59

2

Question 60

When does fermentation occur?

Answer 60

When there is an absense of final electron acceptors (no oxygen, no inorganic molecule)

Question 61

3 points about fermentation- -_____ is ______ ____ -________ ____(or other organic molecule) acts as a ________ ______ ______ -__________ _____

Answer 61

- Glucose is partially oxidized - Pyruvic acid acts as a final electron acceptor - Regenerates NAD+

Question 62

The ability to ferment carbohydrates is a common way in helping _____________ and determining its _______. A ______ ______ is what determines whether the microbe ferments the carb or not. Fermentation can also detect ______ _____ ___

Answer 62

identify a particular microorganism and determining its classification pH indicator CO2 gas production