Chapter 5 Microbiology

Front 1

What are the two classes of chemical reactions that metabolism can be divided into?

Back 1

those that release energy and those that require energy.

Front 2

What two enzyme-regulated processes are involved in digestion?

Back 2

Anabolism + Catabolism

Front 3

This enzyme-regulated chemical reaction releases energy by breaking down complex organic compounds into simpler ones:

Back 3

Catabolism

Front 4

Give an example of Catabolism:

Back 4

when cells break down sugars into carbon dioxide and water.

Front 5

This enzyme-regulated reaction, requires energy to build complex organic molecules from simpler ones:

Back 5

Anabolism

Front 6

Examples of anabolic processes are:

Back 6

the formation of proteins from amino acids, nucleic acids from nucleotides, and polysaccharides from simple sugars.

Front 7

The coupling of energy-requiring (anabolism) and energy-releasing (catabolism) reactions is made possible through what molecule?

Back 7

ATP

Front 8

How does ATP play the role in coupling anabolic and catabolic reactions?

Back 8

ATP stores energy obtained from catabolic reactions and releases it later to drive anabolic reactions and perform other cellular work.

Front 9

What group of proteins are involved in almost all biologically important chemical reactions?

Back 9

Enzymes

Front 10

A cell's ________________ are determine by its enzymes, which are in turn determined by the cell's genetic makeup.

Back 10

metabolic pathways (sequences of chemical reactions)

Front 11

Explain the collision theory:

Back 11

the collision theory states that chemical reactions can occur when atoms, ions, & molecules collide

Front 12

What factors determine whether a collision will cause a chemical reaction?

Back 12

the velocities of the colliding particles, their energy, and their specific chemical configurations.

Front 13

The collision energy required for a chemical reaction, which is also the amount of energy needed to disrupt the stable electronic configuration of any specific molecule so that the electrons can be rearranged is called what?

Back 13

activation energy

Front 14

The frequency of collisions w/enough energy to bring about a reaction

Back 14

reaction rate

Front 15

What is one way to increase the reaction rate of a substance and how does it do so?

Back 15

Raising its temperature, increases both frequency of collisions and the number of molecules that attain activation energy.

Front 16

Substances that can speed up a chemical reaction without being permanently altered themselves are called ____________.

Back 16

catalysts

Front 17

In living cells, these serve as biological catalysts...

Back 17

enzymes

Front 18

Enzymes act on a specific substance, called its what?

Back 18

substrate (substrates, when there are two or more reactants)

Front 19

The surface of the substrate contacts a specific region of the surface of the enzyme molecule, called what?

Back 19

The active site

Front 20

What are the factors that influence enzymatic activity?

Back 20

temperature, pH, substrate concentration, state of subdivision, and the prescience or absence of inhibitors

Front 21

Give two examples of electron transfer:

Back 21

*oxidation

*reduction

Front 22

What is Oxidation?

Back 22

*Loss of electrons

*Loss of Hydrogen

*Addition of Oxygen

Front 23

What is reduction?

Back 23

*Gain of electrons

*Gain of Hydrogen

*Loss of Oxygen

Front 24

What is the fully reduced form of Carbon?

Back 24

Methane

Front 25

What is the fully oxidized form of Carbon?

Back 25

CO2

Front 26

What is the pairing of oxidation and reduction reactions are called?

Back 26

oxidation-reduction or a redox reaction

Front 27

Since oxidation/reduction reactions are often coupled, what occurs each time a substance is oxidized?

Back 27

Another substance is reduced.

Front 28

____________ from transfer of electrons (oxidation) of one compound to another (reduction) is used to generate ATP in the electron transport chain

Back 28

Energy released

Front 29

Energy released from transfer of electrons (oxidation) of one compound to another (reduction) is used to ______________________________

Back 29

generate ATP in the ELECTRON TRANSPORT CHAIN

Front 30

First considering their energy source, we generally classify all organisms as what?

Back 30

Either Chemotrophs (chemical) or phototrophs (light)

Front 31

Phototrophs

Back 31

Use light as their primary energy source.

Front 32

Chemotrophs

Back 32

depend on redox reactions of inorganic or organic compounds for energy.

Front 33

For their principal carbon source, autotrophs (self-feeders) use________________.

Back 33

Carbon dioxide

Front 34

For their principal carbon source, heterotrophs (feeders on others) require_________________.

Back 34

an organic carbon source.

Front 35

If we combine the energy and carbon sources, we derive the following nutritional classifications for organisms:

Back 35

*photoautotrophs

*photohetertrophs

*chemoautotrophs

*chemoheterotrophs

Front 36

Name some characteristics of photoautotrophs:

Back 36

*they use light as energy source and CO2 for carbon source

*they include green and purple sulfur bacteria, green algae, green plants, and cyanobacteria

Front 37

What is the photosynthetic process of cyanobacteria, algae, and green plants?

Back 37

The hydrogen atoms of water are used to reduce CO2, and oxygen gas is given off.

Front 38

When a photosynthetic process produces O2, it is sometimes called what?

Back 38

oxygenic

Front 39

Do green and purple sulfur bacteria produce oxygen after photosynthesis?

Back 39

NO

Front 40

Since green and purple sulfur bacteria do not produce oxygen after photosynthesis they are considered what?

Back 40

anoxygenic photoautotrophs

Front 41

anoxygenic photoautotrophs cannot:

Back 41

use H2O to reduce CO2 and don't produce O2

Front 42

Green and purple sulfur bacteria use what to to reduce CO2?

Back 42

They use sulfur compounds (H2S) or hydrogen.

Front 43

Give some characteristics of photoheterotrophs:

Back 43

*they use light for energy but can't convert CO2 to sugar

*sources of carbon: alcohols, fatty acids, and carbs

*they are anoxygenic

*green and purple NONsulfur bacteria are photoheterotrophs

Front 44

Give some characteristics of chemotautotrophs:

Back 44

*use electrons from inorganic sources as energy and CO2 for carbon

*inorganic sources of energy include: H2S, Sulfur, ammonia, nitrite (NO2-)

* energy is stored as ATP

Front 45

Give some characteristics of chemoheterotrophs:

Back 45

*use electrons from hydrogen atoms in organic compounds for both energy and carbon source

*we are chemohetertrophs, b/c we eat organic molecules

Front 46

The two most common sources of energy and carbon sources are:

Back 46

photoautotrophs and chemoheterotrophs

Front 47

The mechanism of enzymatic action is also known as:

Back 47

the lock and key mechanism

Front 48

The general sequence of the lock and key mechanism:

Back 48

1) the substrate contact the active site on enzyme to form

2) an enzyme-substrate complex

3) the substrate is then transformed into products,

4) the products are released, and

5) the enzyme is recovered unchanged.

Front 49

As a result of the events of the lock and key mechanism, what occurs?

Back 49

an enzyme speeds up a chemical reaction

Front 50

An effective way to control the growth of bacteria is to control their enzymes with what?

Back 50

enzyme inhibitors

Front 51

Enzyme inhibitors are classified as either:

Back 51

competitive or noncompetitive inhibitors

Front 52

A competitive inhibitor does what?

Back 52

*fills the active site of the enzyme

*competes with normal substrate (molecule that binds to enzyme) for the active site.

Front 53

What does a noncompetitive inhibitor do?

Back 53

*doesnt compete with the substrate for the active site

*has own extra binding site (allosteric inhibition)

*binds to site other than substrates binding site called allosteric site

*the binding causes the active site to change its shape, making it nonfunctional

Front 54

How would one test for inhibition?

Back 54

Measure rate of reaction vs substrate concentration

Plot 1/Velocity of reaction rate vs 1/ [S] concentration of substrate

Front 55

After plotting, you get all lines intercepting on the y-axis, what does this indicate?

Back 55

This indicates a competitive inhibitor

Front 56

After plotting, you get all lines intercepting on the x-axis, what does this indicate?

Back 56

This indicates that you have a noncompetitive inhibitor

Front 57

What is feedback inhibition?

Back 57

an inhibitor that blocks the pathway that made it

Front 58

What is respiration?

Back 58

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

Front 59

An essential feature of respiration is the operation of an electron transport chain which consist of:

Back 59

*glycolysis (breaking down glucose)

* Krebs Cycle and

*oxidative phosphorylation

Front 60

What are the two types of respiration?

Back 60

Aerobe which uses oxygen and anaerobe which does not use oxygen and may even be killed by it.

Front 61

What is the final electron acceptor in aerobic respiration?

Back 61

O2

Front 62

What is the final electron acceptor in anaerobic respiration?

Back 62

an inorganic molecule other than O2 or, rarely an organic molecule.

Front 63

What is glycolysis (splitting of sugar) ?

Back 63

it is the oxidation of glucose to pyruvic acid, which is usually the first stage of carbohydrate catabolism

Front 64

What is glycolysis also called?

Back 64

the Embden-Meyerhof pathway.

Front 65

Does glycolysis require energy?

Back 65

No, it can occur wether energy is present or not.

Front 66

What are the starting and ending products of glycolysis?

Back 66

Glucose and pyruvic acid.

Front 67

What are the 3 enzymes involved in glycolysis and what are their functions?

Back 67

*kinase- enzyme that transfers phosphate groups

*isomerase- enzyme that changes the shape of molecules

*aldolase -splits Fructose-1, 6 di-PO4 into two separate molecules

Front 68

Step 1 of glycolysis:

Back 68

Is the conversion of Glucose into Glucose-6-PO4, catalyzed by the enzyme glucokinase. This step is considered the activating reaction because ATP is breaking down to form ADP, preparing the phosphate transfer.

Front 69

Step 2 of glycolysis:

Back 69

is the conversion of Glucose-6-PO4 into Fructose-6-PO4, catalyzed by the enzyme isomerase. The purpose here is to free up the #1 carbon moving it out of the ring.

Front 70

Step 3 of glycolysis:

Back 70

is the conversion of Fructose-6PO-4 into Fructose-1, 6-di-PO4 through the enzyme phosphohexokinase. The purpose here is to add phosphate to #1 carbon for symmetry, you want a phosphate on both sides

Front 71

Step 4 of glycolysis:

Back 71

The enzyme aldolase splits Fructose-1, 6-di-PO4 into 2 separate molecules that are isomers of each other, each being 3 carbon molecules. One is Dihydroxy acetone phosphate (DHAP) and Glyceraldehide (GAP).

Front 72

Step 5 of glycolysis:

Back 72

By the enzyme isomerase, it will reorganize DHAP into GAP and you will now have two GAPs.

Front 73

What are the name of the coenzymes that appears in the glycolytic chain?

Back 73

NAD and NADH

*NAD+ is reduced to NADH

Front 74

How many ATPs are being produced in glycolysis?

Back 74

4 ATPs are being produced but we lose 2 to get glycolysis started. So there is a net gain of 2 molecules of ATP for each molecule of glucose that is oxidized.

Front 75

What is lactic acid?

Back 75

it is the reduced form of pyruvic acid and pyruvic acid is the oxidized form of lactic acid.

Front 76

Why is lactic acid not a part of respiration?

Back 76

because it is not permanent, sooner or later it will oxidize back to pyruvic acid.

Front 77

Is glycolysis aerobic or anaerobic breathing and why?

Back 77

Glycolysis is anaerobic breathing because an anaerobic organism can only produce 2 ATPs from glucose.

Front 78

Where does glycolysis occur?

Back 78

in the cytoplasm

Front 79

How many ATPs can aerobic organisms produce from glucose?

Back 79

38 ATPs

Front 80

After respiration, pyruvic acid moves into mitochondria, now making everything...

Back 80

aerobic

Front 81

What 3 transition steps does pyruvic acid endure to be able to enter the Krebs Cycle?

Back 81

1)removal of H

2) removal of the rest of the carboxyl group in form of CO2

3) binding of coenzyme A to form acetyl group, CoA the cargo carrier, carries acetyl group into Krebs Cycle drops it off and exits.

Front 82

What is the first molecule of the Krebs cycle?

Back 82

Oxaloacetic acid (OAA)

Front 83

How does OAA become citric acid?

Back 83

As CoA enters Krebs cycle, it detaches from the 2 carbon acetyl group, which then combines with the 4 carbon compound OAA to form the 6 carbon citric acid.

Front 84

At what points in the Krebs Cycle do the CO2s come out?

Back 84

In transition and in Krebs Cycle

Front 85

How many ATP's are being produced in Krebs Cycle and how?

Back 85

*each pyruvic acid is producing 15 ATPs (3 in transition phase and 12 in Krebs)

*we have 2 pyruvic acids from glycolysis=30 ATPs

*+2 more from glycolysis=32 ATPs

* +2 NADH (3ATPs each)=38ATPS total

Front 86

Since 38 ATPs are being produced in Krebs Cycle what type of respiration is this?

Back 86

Aerobic respiration

Front 87

What is oxidative phosphorylation and the electron transport system (ETC or ETS)?

Back 87

A series of electron transfers and redox reactions, giving up energy with every transfer.

Front 88

what is ATP synthase?

Back 88

this is the process of gathering energy lost from electron transfer

Front 89

In the ETC how many ATPs are being made?

Back 89

2 ATPS by FADH

Front 90

What is the final electron acceptor in ETC?

Back 90

O2

Front 91

What is the reduced form of O2 and the final product of ETC?

Back 91

H2O (water)