week3- microbial metabolism Flashcards
4 main microorganism groups
bacteria
protozoa
fungi
virus
Define metabolism
Sum of all chemical or biochemical reactions that occur in an organism
What is the ultimate function or goal of metabolism in microbes?
– Ultimate function of metabolism in a microbe is to reproduce the organism
Understand the principles that guide metabolism in a microorganism (
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).
What molecule stores energy in microbes and how is that energy stored?
Energy is stored in adenosine triphosphate (ATP)—stored in the third phosphate bond.
Describe anabolism (include the purpose)—what types of molecules do microbes “anabolize” or “synthesize”?
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
Describe catabolism (include purpose)—-what are the types of molecules that a microbe will catabolize?
Break larger molecules into smaller products
* Can generate energy (usually as ATP)
(Fatty Acids, Amino Acids, Sugars, Nucleotides).
What is an oxidation-reduction reaction?
Transfer of electrons from an electron donor to
an electron acceptor
Describe an enzyme including its function and how it works in a reaction
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
rate of enzymes
how well metabolism occurs
increase rate=increase metabolism
lower rate=lower metabolism
What is the activation energy for a reaction?
(energy needed to start the reaction)
Describe how temperature affects rate of enzymes
High temp = higher rate of enzyme
too high of temp = denature enzyme
decrease temp=lower rate of enzyme
Describe how PH influence the RATE of enzymes
an increase OR decrease in pH will denature
enzymes so decrease activity
Describe how concentration of substrate+emzyme influence the RATE of enzymes
– Enzyme and substrate concentrations- Increased concentration of enzyme and/or substrate will increase activity
– Decreased concentration of either enzyme or
substrate will decrease activity
Describe how inhibitors influence the RATE of enzymes
– Presence of inhibitors-Enzyme inhibitors will decrease enzyme activity
no inhibitors= normal speed
What is an enzyme “inhibitor”?
Substances that prevent the enzyme from binding
to the substrate
Differentiate between how a “competitive” enzyme inhibitor and a “non-competitive” enzyme inhibitor work
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
cellular respiration
complete breakdown of a carb
generates atp
What is the most common carbohydrate/sugar used as a carbon source for microbes? What other sugars can they break down?
Glucose most common carbohydrate used
– Other sugars such as lactose, sucrose, mannitol or maltose can be used
In addition to carbohydrates, what other molecules can be catabolized by microbes to generate ATP?
Amino acids and fats can be catabolized as well
Differentiate between aerobic respiration, anaerobic respiration
Aerobic respiration: oxygen serves as final electron
acceptor (in etc)
- Anaerobic respiration: molecule other than oxygen serves as final electron acceptor(in etc)
How is fermentation different from aerobic/anaerobic
No 02 required + specific enzymes
partial breakdown of carbs
only makes 2 atp
makes molecules for normal respiration
List steps in order of the complete breakdown of carbohydrates using respiration.
Glycolysis)
–Synthesis of acetyl-CoA
–Krebs cycle (Citric Acid Cycle)
–Electron transport chain
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)?
electron transport chain-choose to use o2 or no 34 ATP
in Prokaryotes (38 Total), 32 ATP in Eukaryotes (36 Total).
