week3- microbial metabolism

Question 1

4 main microorganism groups

Answer 1

bacteria
protozoa
fungi

virus

Question 2

Define metabolism

Answer 2

Sum of all chemical or biochemical reactions that occur in an organism

Question 3

What is the ultimate function or goal of metabolism in microbes?

Answer 3

– Ultimate function of metabolism in a microbe is to reproduce the organism

Question 4

Understand the principles that guide metabolism in a microorganism (

Answer 4

Every cell acquires nutrients. Some microorganisms absorb nutrients through cellmembrane while others decompose dead organisms or phagocytize other organisms.
Nutrients required for metabolism.
* Metabolism requires energy from light or from catabolism of nutrients (ADP to ATP).
* Energy is stored in adenosine triphosphate (ATP)—stored in the third phosphate bond.
* Cells also catabolize nutrients to form precursor metabolites (building blocks).
* Precursor metabolites, energy from ATP, and enzymes are used in anabolic reactions.
* Enzymes plus ATP help link the smaller molecules together to form larger
macromolecules (anabolism).
* Cells grow by assembling macromolecules into cellular structures.
* Cells reproduce once they have doubled in size (reproduction = growth = increase in
number of microorganisms).

Question 5

What molecule stores energy in microbes and how is that energy stored?

Answer 5

Energy is stored in adenosine triphosphate (ATP)—stored in the third phosphate bond.

Question 6

Describe anabolism (include the purpose)—what types of molecules do microbes “anabolize” or “synthesize”?

Answer 6

The process of building larger and more complex molecules from smaller molecules. Requires Energy/ATP. (Carbohydrates, Lipids, Proteins, DNA, RNA)

creates all molecules that let the cell divide- doubles how much dna/rna/ribosomoes in cell so it can divide

Question 7

Describe catabolism (include purpose)—-what are the types of molecules that a microbe will catabolize?

Answer 7

Break larger molecules into smaller products
* Can generate energy (usually as ATP)

(Fatty Acids, Amino Acids, Sugars, Nucleotides).

Question 8

What is an oxidation-reduction reaction?

Answer 8

Transfer of electrons from an electron donor to
an electron acceptor

Question 9

Describe an enzyme including its function and how it works in a reaction

Answer 9

Enzymes are organic catalysts (mostly proteins)
-help a reaction start/go
-lower activation energy
* Most are composed of proteins—some are
RNA (ribozymes)

fit like lock and key into substrate

Question 10

rate of enzymes

Answer 10

how well metabolism occurs

increase rate=increase metabolism
lower rate=lower metabolism

Question 11

What is the activation energy for a reaction?

Answer 11

(energy needed to start the reaction)

Question 12

Describe how temperature affects rate of enzymes

Answer 12

High temp = higher rate of enzyme
too high of temp = denature enzyme
decrease temp=lower rate of enzyme

Question 13

Describe how PH influence the RATE of enzymes

Answer 13

an increase OR decrease in pH will denature
enzymes so decrease activity

Question 14

Describe how concentration of substrate+emzyme influence the RATE of enzymes

Answer 14

– Enzyme and substrate concentrations- Increased concentration of enzyme and/or substrate will increase activity

– Decreased concentration of either enzyme or
substrate will decrease activity

Question 15

Describe how inhibitors influence the RATE of enzymes

Answer 15

– Presence of inhibitors-Enzyme inhibitors will decrease enzyme activity

no inhibitors= normal speed

Question 16

What is an enzyme “inhibitor”?

Answer 16

Substances that prevent the enzyme from binding
to the substrate

Question 17

Differentiate between how a “competitive” enzyme inhibitor and a “non-competitive” enzyme inhibitor work

Answer 17

C- blocks the active site on enzyme so substrate cant connect

NC-binds to enzyme, complete changes the shape of active site on enzyme so substrate doesn’t fit

Question 18

cellular respiration

Answer 18

complete breakdown of a carb
generates atp

Question 19

What is the most common carbohydrate/sugar used as a carbon source for microbes? What other sugars can they break down?

Answer 19

Glucose most common carbohydrate used
– Other sugars such as lactose, sucrose, mannitol or maltose can be used

Question 20

In addition to carbohydrates, what other molecules can be catabolized by microbes to generate ATP?

Answer 20

Amino acids and fats can be catabolized as well

Question 21

Differentiate between aerobic respiration, anaerobic respiration

Answer 21

Aerobic respiration: oxygen serves as final electron
acceptor (in etc)

• Anaerobic respiration: molecule other than oxygen serves as final electron acceptor(in etc)

Question 22

How is fermentation different from aerobic/anaerobic

Answer 22

No 02 required + specific enzymes

partial breakdown of carbs

only makes 2 atp

makes molecules for normal respiration

Question 23

List steps in order of the complete breakdown of carbohydrates using respiration.

Answer 23

Glycolysis)
–Synthesis of acetyl-CoA
–Krebs cycle (Citric Acid Cycle)
–Electron transport chain

Question 24

In which reaction will most of the ATP be generated?
How many net ATP molecules can be generated at the end of respiration (prokaryotic vs eukaryotic)?

Answer 24

electron transport chain-choose to use o2 or no 34 ATP

in Prokaryotes (38 Total), 32 ATP in Eukaryotes (36 Total).

Question 25

What reaction can be an alternative to Glycolysis?

Answer 25

Pentose Phosphate Pathway

Question 26

useful fermentation products

Answer 26

NADH, ATP, Pyruvate.

Question 27

How is the carbohydrate fermentation characteristics of a microbe useful in lab identification of microbes?

Answer 27

So you know how to identify microorganisms based off of what types of carbs it ferments