Module 5 Microbial Metabolism (VIDEOS)

Question 1

refers to all of the biochemical reactions taking place in an organism.

Answer 1

Metabolism

Question 2

2 General Categories of anabolism

Answer 2

Catabolism and Anabolism

Question 3

builds larger organic compounds, such as carbohydrates and proteins, from simpler monomers, including glucose and amino acids.

Answer 3

Anabolism

Question 4

hydrolyses polymers into simpler molecules, such as carbon dioxide, ammonia and water.

Answer 4

Catabolism

Question 5

From an energy perspective, anabolic reactions form bonds which requires energy. Such energy-requiring processes are considered

Answer 5

endergonic reactions.

Question 6

catabolic reactions break bonds, releasing energy. These processes are called

Answer 6

exergonic reactions.

Question 7

• catalyze all chemical reactions in cells.
• are usually proteins
• increase the probability of a chemical reaction taking place, while they themselves remain unchanged
• are able to accomplish in fractions of a second, what otherwise might take hours, days or even longer to happen spontaneously under normal biological conditions.

Answer 7

Enzymes

Question 8

4 Characteristics Common to All Enzymes:

Answer 8

reusable
highly specific
have an active site
required in small amounts

Question 9

An enzyme molecule has an active site where it binds the substrate molecule. The substrate will then bind to the active site to form an

Answer 9

enzyme-substrate complex

Question 10

TRUE OR FALSE

enzyme hydrolyzes a substrate, and also catalyze dehydration reactions, which would bind 2 or more molecules together forming a larger molecule.

Answer 10

TRUE

Question 11

the 3-dimensional shape of the enzymes’ active site recognizes and holds the substrate in an enzyme-substrate complex. While in the complex, chemical bonds in the substrate are stretched or weakened by the enzyme causing the bind to break.

Answer 11

hydrolysis reactions of enzymes

Question 12

the electron shells of the substrates in the enzyme-substrate complex are forced to overlap in the spot where a chemical bond will form. Thus, recognition of the substrate or substrates is a highly controlled, nonrandom event.

Answer 12

synthesis reaction of enzymes

Question 13

plays a key role in metabolism, because they provide an alternate reaction pathway of less resistance. That is, with a lower activation energy barrier.
They assist in the destabilization of bonds and the formation of new ones, by separating or joining atoms in a carefully orchestrated fashion. Some enzymes are made up entirely of protein.

Answer 13

Enzymes

Question 14

Enzymes contain small non-protein substances called ________. When a non-protein co-factor is a small organic molecule, we refer to it as a _____. They will participate in the catalytic reaction.

Answer 14

co-factors
co-enzyme

Question 15

is a sequence of chemical reactions; each reaction catalyzed by a different enzyme in which the product of one reaction serves as a substrate for the next reaction.

a series of enzymes transforms an initial substrate into a final end product.

Answer 15

metabolic pathway

Question 16

The pathway starts with the initial substrate and finishes with the final end product. The products of the in between stages are referred to as __________.

Answer 16

intermediates

Question 17

the inhibitor will have a structure that is similar to the normal substrate and will compete for the enzyme’s active site.

would reduce the productivity of the metabolic pathway by slowing down or stopping the pathway altogether.

Answer 17

competitive inhibition

Question 18

One of the most common ways of a modulating enzyme activity, is for the final end product of metabolic pathway to inhibit an enzyme in that same pathway.
If the first enzyme in the pathway is inhibited, then no product is available as input for the rest of the pathway.

Answer 18

feedback inhibition.

Question 19

when the final end product or end molecule binds to an allosteric site, the shape of the active site changes and can no longer bind with the substrate

Answer 19

noncompetitive inhibition

Question 20

Another way of modulating an enzyme, is by blocking its active site so that the normal substrate cannot bind

Answer 20

Competitive inhibition

Question 21

other site where the inhibitor attaches

Answer 21

allosteric site

Question 22

is the universal energy currency in all cells. In many metabolic reactions, energy is needed along with enzymes for reactions to occur.

are relatively unstable

Answer 22

ATP, adenosine triphosphate.

Question 23

Breaking the so-called high-energy bond in ATP that holds the last phosphate group on the molecule, produces a more stable molecule

Answer 23

adenosine diphosphate or ADP

Question 24

The addition of a phosphate group to another molecule

Answer 24

phosphorylation

ATP -> ADP (energy released)
ADP -> ATP (energy required)

Question 25

all cells make ATP by harvesting energy from exergonic metabolic pathways, such as the hydrolysis of food molecules. Such a process is called

Answer 25

cellular respiration

Question 26

• contains stored energy that can be extracted.
• is a primary source for generating ATP.

Answer 26

Glucose

Question 27

if cells consume oxygen in making ATP, the process is called

Answer 27

aerobic respiration

Question 28

In other instances, cells can make almost equally substantial amounts of ATP without using oxygen in a process called ___________.

another organic molecule replaces oxygen

Answer 28

anaerobic respiration

Question 29

Another form of anaerobic metabolism is _________.

Answer 29

fermentation

Question 30

Aerobic cellular respiration occurs in _____. The process is represented by the following chemical equation: glucose and oxygen along with ADP are used to produce carbon dioxide, water and ATP.

Answer 30

obligate aerobes

Question 31

Aerobic cellular respiration can be conveniently divided into 3 stages:

Answer 31

glycolysis, the citric acid cycle, and oxidative phosphorylation

Question 32

is the first stage of energy extraction. Glycolysis is a metabolic pathway yielding ATP and NADH

Answer 32

Glycolysis

Question 33

In glycolysis, the splitting of glucose occurs in the ______of the microorganism and involves a metabolic pathway that converts the initial 6-carbon substrate, glucose, into 2 3-carbon molecules called ______.

Answer 33

cytosol;

pyruvate

Question 34

is a series of chemical reactions that are referred to as a cycle, because the end product formed is used as a substrate to initiate the entire pathway.

Answer 34

citric acid cycle or Kreb’s cycle,

Question 35

is the process by which most of the ATP molecules form. Oxidative phosphorylation refers to a sequence of reactions in which 2 events happen: electrons transport and ATP synthesis.

Answer 35

Oxidative phosphorylation

Question 36

The actual mechanism for ATP synthesis comes from the pumping of proteins through a process

Answer 36

chemiosmosis

Question 37

Proteins are broken down into individual amino acids. Enzymes then convert many amino acids to pathway components by removing the amino group and substituting a carbonyl group. This process is called ______ which is ________.

Answer 37

deamination; protein metabolism

Question 38

Fats are extremely valuable energy sources because their chemical bonds contain enormous amounts of chemical energy. Although proteins are generally not considered energy sources, cells use them for energy when and fats are in short supply

Answer 38

Fat metabolism

Question 39

create ATP in the absence of oxygen. In environments that are anoxic and without an alternative electron acceptor, much of the organic material will be catabolized through fermentation.

is the enzymatic process for producing ATP using endogenous organic compounds as both electron donors and acceptors. Exogenous electron acceptors include oxygen, nitrate, sulfate and carbonate.

Answer 39

Fermentation

Question 40

Photosynthesis can be separated into (2)

Answer 40

light dependent and light-independent reactions.

Question 41

In the first part of photosynthesis, light energy is converted into or fixed as chemical energy in the form of ATP and NADPH. Thus, the process is referred to as the______________ because light energy is needed for the process.

Answer 41

energy-fixing reactions or light-dependent reactions

Question 42

ight energy is absorbed by a green pigment called

Answer 42

chlorophyll A

Question 43

Chlorophylls and accessory pigments make up light receiving formation of ATP in a process called _____________.

Answer 43

photophosphorylation

Question 44

In the second stage of photosynthesis, another cycle metabolic pathway forms carbohydrates. This process is known as the __________, because carbon in carbon dioxide is trapped or fixed into carbohydrates and other organic molecules.

Answer 44

carbon-fixing reactions or light-independent reactions or Calvin cycle

Question 45

In addition to cyanobacteria, a few other groups of bacteria also can trap energy by photosynthesis. 2 such groups are the ___________ and _________, so named because of the colors imparted to them by their pigments. These bacterial organisms have chlorophyll-like pigments known as _________to distinguish them from other chlorophylls.

Answer 45

green bacteria and purple bacteria; bacteriochlorophylls

Question 46

In the energy fixing reactions, the organisms do not use water as a source of hydrogen ions and electrons. Consequently, no oxygen is liberated and the process, therefore, is called ________________.

Answer 46

an-oxygenic photosynthesis.

Question 47

Microorganisms must meet certain nutritional requirements for growth. Besides water, which is an absolute necessity, they need nutrients that can serve as energy sources and raw materials for the synthesis of cell components. These generally include proteins for structural compounds and enzymes, carbohydrates for energy, and a series of vitamins minerals and inorganic salts.

Answer 47

Patterns of metabolism

Question 48

2 different patterns exist for satisfying an organism’s metabolic needs. These patterns are _________and ________.

are primarily based on the source of carbon used for making cellular components.

Answer 48

autotrophy heterotrophy

Question 49

Organisms that synthesize their own foods from simple carbon sources, such as carbon dioxide, are referred to as _________

Answer 49

autotrophs

Question 50

Those that use light as energy sources, such as cyanobacteria, are called _________.

Answer 50

photoautotrophs

Question 51

Microorganisms including the cyanobacteria and algae can carry out photosynthesis using water and producing oxygen gas in a process called _______________, while other bacterial species carry out _____________ using hydrogen sulfide rather than water and produce sulfur granules rather than oxygen gas.

Answer 51

oxygenic photosynthesis

an-oxygenic photosynthesis

Question 52

Another group of autotrophs do not use light as an energy source. Instead, they use inorganic compounds and are referred to as .

Answer 52

chemoautotrophs

Question 53

2 types of heterotrophs

Answer 53

photoheterotrophs and Chemoheterotrophic

Question 54

use light as their energy source and preformed organic compounds such as fatty acids and alcohols as their sources of carbon. Photoheterotrophs include certain green non-sulfur and purple non-sulfur bacteria.

Answer 54

photoheterotrophs

Question 55

_____________ microorganisms are those that feed exclusively one dead organic matter commonly called _______

Answer 55

Chemoheterotrophic; saprobes

Question 56

In contrast, chemoheterotrophs that feed on living organic matter such as human tissue, are commonly known as ____________

Answer 56

parasites