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Flashcards in Microbial Metabolism Deck (43)
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1

enzyme

an organic catalyst

2

function of a catalyst

increases the rate of reaction by lowering the activation energy

3

catabolism

the breakdown of larger molecules into smaller products, releasing energy that is generally used to synthesise ATP

4

metabolic pathway

series of chemical reactions, typically catalysed by an enzyme, that convert an initial molecule into an end product

5

activation energy

the energy required to weaken and break existing bonds

6

endergonic

energy released forming new bonds is less than that required to break them

7

exergonic

energy released forming new bonds is greater than that required to break them

8

active site

functional site of an enzyme, its shape is complimentary to its substrate

9

metabolism

sum total of all chemical reactions occurring within an organism

10

what is the ultimate function of metabolism?

to gather energy and reproduce the organism

11

What are the two general processes metabolism encompasses?

catabolism and anabolism

12

anabolism

otherwise known as biosynthesis, stored energy (generally in the form of ATP) is used to synthesise or assemble complex molecules

13

what happens to energy released from catabolic processes?

it is used to drive anabolic processes

14

where does the energy go in an endergonic reaction?

it is stored in the bonds of the products of the reaction

15

what are the three parts of adenosine triphosphate?

ribose (sugar), adenine (nitrogenous base), three phosphate groups (PO43-)

16

what does ATP do for a cell?

stores energy to be released in exergonic reactions and supplies energy required by endergonic reactions

17

ATP -> ADP exergonic or endergonic?

exergonic

18

ADP -> ATP exergonic or endergonic?

endergonic

19

converting ADP to ATP requires what?

ADP, inorganic phosphate (Pi), energy

20

what kind of chemical reaction breaks ATP's phosphate bonds? Is this exergonic or endergonic?

hydrolysis, exergonic

21

how is the energy released from ATP hydrolysis used?

generally coupled to endergonic reactions by transferring the removed phosphate to another molecule (phosphorylation)

22

phosphorylation

Phosphorylation is the addition of a phosphate (PO43−) group to a protein or other organic molecule (see also: organophosphate). Phosphorylation turns many protein enzymes on and off, thereby altering their function and activity. Protein phosphorylation is one type of post-translational modification.

23

obligate aerobe

An obligate aerobe is an organism that requires oxygen to grow. Through cellular respiration, these organisms use oxygen to metabolise substances, like sugars or fats, to obtain energy. In this type of respiration, oxygen serves as the terminal electron acceptor for the electron transport chain. Aerobic respiration has the advantage of yielding more energy (adenosine triphosphate or ATP) than fermentation or anaerobic respiration, but obligate aerobes are subject to high levels of oxidative stress.

24

an organism that requires oxygen to grow.

obligate aerobe

25

obligate anaerobes

Obligate anaerobes are microorganisms that are killed by normal atmospheric concentrations of oxygen (21% O2). Oxygen tolerance varies between species, some capable of surviving in up to 8% oxygen, others losing viability unless the oxygen concentration is less than 0.5%. An important distinction needs to be made here between the obligate anaerobes and the microaerophiles. Microaerophiles, like the obligate anaerobes, are damaged by normal atmospheric concentrations of oxygen. However, microaerophiles metabolise energy aerobically, and obligate anaerobes metabolise energy anaerobically. Microaerophiles therefore require oxygen (typically 2-10% O2) for growth. Obligate anaerobes do not.

26

microorganisms that are killed by normal atmospheric concentrations of oxygen but do not require it to function

obligate anaerobes

27

microaerophile

microaerophiles are microorganisms that requires oxygen to survive, but requires environments containing lower levels of oxygen than are present in the atmosphere (i.e. <21% O2; typically 2-10% O2). many microaerophiles are also capnophiles, requiring an elevated concentration of carbon dioxide (e.g. 10% CO2 in the case of genus Campylobacter).

28

microorganisms that are killed by normal atmospheric concentrations of oxygen, but require small amounts to survive

microaerophiles
(typically 2-10% O2). many microaerophiles are also capnophiles, requiring an elevated concentration of carbon dioxide (e.g. 10% CO2 in the case of genus Campylobacter).

29

microorganism that requires oxygen to survive, but requires environments containing lower levels of oxygen than are present in the atmosphere

microaerophile
(typically 2-10% O2). many microaerophiles are also capnophiles, requiring an elevated concentration of carbon dioxide (e.g. 10% CO2 in the case of genus Campylobacter).

30

capnophiles

capnophiles are microorganisms which thrive in the presence of high concentrations of carbon dioxide. some capnophiles may have a metabolic requirement for carbon dioxide, while others merely compete more successfully for resources under these conditions. the term is a generally a descriptive one and has less relevance as a means of establishing a taxonomic or evolutionary relationship among organisms with this characteristic.