(exam 1) ch 5 microbial metabolism

Question 1

what is metabolism?

Answer 1

is the buildup and breakdown of nutrients within a cell

Question 2

why is metabolism necessary for life?

Answer 2

Provides energy and creates substances that sustain life

Question 3

what are catabolic pathways?

Answer 3

pathways that break down macromolecules into simple component parts, releasing energy in the process (breaking down)

Question 4

what are anabolic pathways?

Answer 4

pathways that build up macromolecules by combining simpler molecules, using energy in the process (build up)

Question 5

what are some examples of positive effects of bacterial metabolism?

Answer 5

Nitrogen cycle, food production, sewage treatment

Question 6

what are some examples of negative effects of bacterial metabolism?

Answer 6

Disease and food spoilage

Question 7

The ability of bacteria to grow and thrive in certain environments is directly related to what?

Answer 7

their specific metabolism

Question 8

Differences in metabolism between bacterial species are based on differences in what?

Answer 8

the enzymes expressed by bacteria (Type and amount of expressed enzymes is based in the bacterial genome)

Question 9

what are enzymes?

Answer 9

biological catalysts

Question 10

what do enzymes act on?

Answer 10

specific substances called substrates

Question 11

what do enzymes do?

Answer 11

Assist with chemical reactions without being altered; they drastically speed up chemical reactions by lowering the activation energy

Question 12

what contacts the enzyme’s active site and what does it form?

Answer 12

contacts the substrate to form an enzyme-substrate complex

Question 13

is the enzyme changed in the reaction?

Answer 13

Enzyme is unchanged and can react with other substrates

Question 14

how do the enzyme and substrate fit together?

Answer 14

lock and key mechanism; Enzymes are specific to certain substrates; Certain compounds may be substrates for several enzymes

Question 15

how is enzyme activity affected by temperature?

Answer 15

Rate of reaction decreases above enzymes optimal temperature due to denaturation (Optimal temp for most pathogens is 35-40oC) it can become inactive or denatures

Question 16

how is enzyme activity affected by pH?

Answer 16

Denaturation can occur above or below optimal pH

Question 17

what is an example of an enzyme inhibitor?

Answer 17

Inhibitors
Antibacterial drugs (e.g. sulfanimide)

Question 18

what are metabolic pathways?

Answer 18

Series of enzymatically catalyzed chemical reactions; Extract energy from organic compounds and ATP is generated from this energy as it is passed (in the form of electrons) between carrier molecules

Question 19

what are two examples of metabolic pathways

Answer 19

oxidation (electrons removed) / reduction (electrons gained) reactions

Question 20

what does ATP stand for?

Answer 20

Adenosine triphosphate (ATP)

Question 21

what is ATP?

Answer 21

“Energy carrier” of living cells; Possesses unstable bonds that can easily be formed/broken to store/provide energy for the cell

Question 22

what is the primary energy source of most microorganisms?

Answer 22

Most microorganisms use carbs (glucose) as their primary energy source

Question 23

what is Carbohydrate Catabolism?

Answer 23

Breakdown of carb molecules to produce energy (Glucose is the most common energy source)

Question 24

what is chemiosmosis?

Answer 24

movement of ions across a semipermeable membrane bound structure, down their electrochemical gradient

Question 25

what is an example of chemiosmosis?

Answer 25

An example of this would be the formation of adenosine triphosphate by the movement of hydrogen ions across a membrane during cellular respiration or photosynthesis.

Question 26

how much ATP is made from cellular respiration (aerobic respiration) ?

Answer 26

38 ATP

Question 27

how much ATP is made from anaerobic respiration?

Answer 27

less than 38 ATP but more than 2

Question 28

how much ATP does fermentation make?

Answer 28

2 ATP

Question 29

how are lipids degraded?

Answer 29

degraded by extracellular lipases

Question 30

when lipids are degraded what is the result?

Answer 30

fatty acids and glycerol

Question 31

how are proteins degraded?

Answer 31

degraded by extracellular proteases and peptidases

Question 32

when proteins are degraded what is the result?

Answer 32

amino acids

Question 33

to produce ATP organisms need what three things?

Answer 33

1) energy source or electron donor 2) electron carriers during oxidation reduction reactions 3) final electron acceptor

Question 34

how do biochemical tests work?

Answer 34

tests identify bacteria by detecting enzymes

Question 35

what is the fermentation test?

Answer 35

bacteria that catabolize carbohydrates or protein produce acid, causing a pH indicator to change color

Question 36

what is the Oxidase test?

Answer 36

identifies bacteria that have cytochrome c oxidase

Question 37

what is the energy source for a chemoheterotroph?

Answer 37

chemical

Question 38

what is the carbon source for a chemoheterotroph?

Answer 38

organic compounds

Question 39

what is an example of a chemoheterotroph?

Answer 39

fermentative bacteria, animals, protozoa, fungi, and bacteria

Question 40

what nutritional type are bacteria considered?

Answer 40

chemoheterotroph

Question 41

what is most energy given off as?

Answer 41

heat

Question 42

what is energy in ATP typically used for?

Answer 42

1) transport across plasma membranes - active transport 2) movement - flagella 3) most used in production of new compounds

Question 43

what are Amphibolic pathways?

Answer 43

(shown as double arrows) function in both anabolism and catabolism