Microbial Metabolism Chp 8 Flashcards
What is metabolism?
The sum of all chemical reactions in a living organism.
What are the two types of metabolic reactions?
Catabolism and anabolism.
What is catabolism?
Breaking down molecules to release energy.
What is anabolism?
Building molecules using energy.
What are hydrolytic reactions?
Reactions that use water to break bonds.
What are dehydration synthesis reactions?
Reactions that release water to form bonds.
What is ATP and why is it important in metabolism?
Adenosine triphosphate; primary energy currency of the cell.
What is an apoenzyme?
An inactive enzyme that requires a cofactor or coenzyme.
What is a holoenzyme?
An active enzyme consisting of an apoenzyme and cofactor/coenzyme.
What are cofactors and coenzymes?
Non-protein molecules that help enzymes function.
Give examples of important coenzymes.
NAD+, NADP+, FAD.
What is an enzyme and what is its role in metabolism?
A biological catalyst that speeds up chemical reactions.
What is activation energy?
The energy required to start a chemical reaction.
How do enzymes work to speed up reactions?
By lowering the activation energy of a reaction.
What is the suffix commonly found in enzyme names?
Enzymes typically end in ‘-ase’.
What are hydrolases and ligases?
Hydrolases break molecules using water; ligases join molecules.
What are electron carriers?
Molecules that transport electrons within cells.
Give examples of electron carriers.
NAD+, NADP+, FAD.
What is a redox reaction?
A chemical reaction involving electron transfer.
What does oxidation mean?
Loss of electrons, making a molecule more positive.
What does reduction mean?
Gain of electrons, making a molecule more negative.
What does OIL RIG stand for?
Oxidation is Loss, Reduction is Gain.
What are autotrophs?
Organisms that obtain carbon from CO2.
What are heterotrophs?
Organisms that obtain carbon from organic molecules.
What are phototrophs?
Organisms that use light as an energy source.
What are chemotrophs?
Organisms that obtain energy from chemicals.
What are chemoautotrophs?
Organisms that obtain energy from inorganic sources.
What are chemoheterotrophs?
Organisms that obtain energy from organic sources.
What are lithotrophs?
Organisms that obtain energy from inorganic compounds.
What are the three mechanisms for ATP generation?
Substrate-level phosphorylation, oxidative phosphorylation, photophosphorylation.
What is substrate-level phosphorylation?
ATP production by direct phosphate transfer.
What is oxidative phosphorylation?
ATP production via the electron transport chain.
What is photophosphorylation?
ATP production using light energy.
What is glycolysis?
The process of breaking glucose into pyruvate.
What are the two phases of glycolysis?
Energy investment phase and energy payoff phase.
What are the net products of glycolysis?
2 ATP, 2 NADH, 2 pyruvate molecules.
What is the fate of pyruvate in aerobic conditions?
Converted to acetyl-CoA and enters the Krebs cycle.
What is the fate of pyruvate in anaerobic conditions?
Undergoes fermentation.
What is cellular respiration?
A process of generating ATP in the presence of oxygen.
What are the three stages of cellular respiration?
Glycolysis, Krebs cycle, electron transport chain.
What is the Krebs cycle?
A series of reactions that extract energy from acetyl-CoA.
What are the main products of the Krebs cycle?
2 ATP, 6 NADH, 2 FADH2 per glucose.
What is the electron transport chain (ETC)?
A series of membrane-bound proteins that transfer electrons.
What is the final electron acceptor in aerobic respiration?
Oxygen.
What is chemiosmosis?
Proton movement down a gradient to generate ATP.
How many ATP molecules are generated from aerobic respiration?
Up to 38 ATP per glucose molecule.
What is anaerobic respiration?
ATP production without oxygen, using alternate electron acceptors.
What are alternative final electron acceptors in anaerobic respiration?
Nitrate, sulfate, carbon dioxide.
What is fermentation?
Anaerobic energy production converting glucose to organic products.
What are the two main types of fermentation?
Lactic acid fermentation and alcoholic fermentation.
What are the main products of fermentation?
Lactic acid, ethanol, carbon dioxide.
What is photosynthesis and how does it relate to metabolism?
A process that converts light energy into chemical energy.
