Question | Answer |
What are the 4 phases of the bacterial growth curve and what goes on during each phase? | Lag: bacteria assessing the nutrients in the medium, no bacterial growthLog: bacteria growing logarithmicallystationary: rate of growth and death equal death/decline: reduced nutrients and overwhelming waste products lead to death of bacteria |
What is the function of an enzyme? | Lowers (decreases) Ea (Activation Energy) so the chemical reaction can readily take place. |
What is the difference between a chemotroph and phototroph? | Chemotrophs use preformed organic compounds (e.g. sugar, starch) as an energy source (e.g. animals)Phototrophs use sunlight as an energy source (e.g. plants) |
What is the difference between a heterotroph and autotroph? | A hetertroph uses preformed organic compounds (e.g. sugar, fats, proteins) as a carbon source (e.g. animals)Autotrophs use carbon dioxide (inorganic carbon) as a carbon source (e.g. plants) |
Define catabolism | The breakdown of complex organic compounds into simpler ones, e.g. when cells break sugars down into CO2 and H2O |
Define anabolism | The building of complex organic molecules from simpler ones, e.g. the formation of proteins from amino acids, nucleic acids from nucleotides |
Define Metabolism | the sum of all chemical reactions within a living organism. |
What are the two types of fermentation reactions that were discussed in class? | 1 - Lactice Acid Fermentation |
What is the role of catalase and superoxide dismutase regarding the oxygen requirements of a bacterial organism? | Catalase neutralizes the hydrogen peroxide by breaking it down to water and oxygen gas. Superoxide dismutase (SOD) neutralizes superoxide. Therefore any organism which metabolizes oxygen must contain these. |
How is an acidophile different from acid tolerant bacteria? | An acidophile requires an acid-rich environment in order to grow, whereas an acid tolerant bacteria doesn’t require any acidity but can tolerate it by producing an enzyme to help neutralize it. |
What is an oxidation reaction? | A reaction in which an atom or molecule loses electrons. |
What is a reduction reaction? | A reaction in which an atom or molecule gains electrons. |