Micro, Chapter 5

Categorize the various nutritional patterns among organisms according to carbon source and mechanisms of carbohydrate catabolism and ATP generation.

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Define amphibolic pathways.

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Describe the major types of anabolism and their relationship to catabolism

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Write a sentence to summarize energy production in cells.

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List the factors that influence enzymatic activity.

TEMPERATURE: pH: SUBSTRATE CONCENTRATION: INHIBITORS:

Describe the chemical reactions of, and list some products of, fermentation.

alcohol- produces ethanol and CO2 lactic acid- produces lactic acid; homolactic- produces lactic acid only heterolactic- produces lactic acid and other compounds

Identify the role of ATP as an intermediate between catabolism and anabolism. p. 112

catabolic reactions provide building blocks for anabolic reactions and furnish the energy need to drive anabolic reactions. this coupling of energy-requiring and energy-releasing reactions is made possible through the molecule ATP. ATP stores energy derived from catabolic reactions and releases it later to drive anabolic reactions and perform other cellular work.

Describe the chemiosmotic model for ATP generation.

electron carriers are organized into three complexes, and protons are pumped across the membrane at three points. in a prokaryotic cells, protons are pumped across the plasma membrane from the cytoplasmic side. in a eukaryotic cell, they are pumped from the matrix side of the mitochondrial membrane of the opposite side. the flow of electrons is indicated with red arrows

Explain the overall function of metabolic pathways.

metabolic pathway is a sequin of enzymatically catalyzed chemical reactions occurring in a cell. organisms release and store energy from organic molecules by a series of controlled reactions rather than in a single burst. if the energy were released all at once, as a large amount of heat, it could not be readily used to drive chemical reactions and would in fact, damage the cell

Define metabolism, and describe the fundamental differences between anabolism and catabolism. p. 112

metabolism- refer to the sum of all chemical reactions within a living organism. catabolism- (energy releasing) the breakdown of complex organic compounds into simpler ones; hydrolytic reactions and exergonic (produce more energy than consumed) anabolism- (energy requiring) the building of complex organic molecules from simpler ones; involve dehydration synthesis reactions and they are endergonic (consume more energy then they produce)

Identify the components of an enzyme. p. 114-115

most consist of both a protein portion called apoenzyme and a nonprotein component called a cofactor.if the cofactor is an organic molecule, it is called a coenzyme. apoenzymes are inactive by themselves; must be activated by cofactors. apoenzyme and cofactor form a holoenzyme. coenzymes asset the enzyme by accepting atoms removed from the substrate or by donating atoms required by the substrate

Provide two examples of the use of biochemical tests to identify bacteria in the laboratory.

one: detection of amino acid catabolizing enzymes involved in decarboxylation and dehydrogenation. two: fermentation test, medium contains protein, a single carbohydrate, a pH indicator, and an inverted Durham tube, which is used to capture gas; urease test & nitrate reductase test

Explain the term oxidation-reduction.

oxidation is the removal of electrons from an atom or molecule, a reaction that often produces energy. reduction is the gain of one more more electrons. these are always coupled; pairing is called oxidation-reduction or a redox reaction

Describe the mechanism of enzyme action. p. 115

1. the surface of the substrate contacts a specific region of the surface of the enzyme molecule, called the active site 2. a temporary intermediate compounds forms, called an enzyme-substrate complex 3. the substrate molecule is transformed by the rearrangement of existing atoms, the breakdown of the substrate molecule, or in combination with another substrate molecule. 4. the transformed substrate molecules--the products of the reaction-- are released from the enzyme molecule because they no longer fit in the active site of the enzyme. 5. the unchanged enzyme is now free to react with other substrate molecules.

Distinguish competitive and noncompetitive inhibition.

COMPETITIVE: fill the active site of an enzyme and compete with the normal substrate for the active site. can do this because of its shape and chemical structure are similar to those of the normal substrate NONCOMPETITIVE: do not compete with the substrate for the enzyme's active site; instead, they interact with another part of the enzyme.

Explain the starting and end products of glycolysis, pentose phosphate pathway, Entner-Doudoroff pathway, Krebs cycle, and electron transport chain.

GLYCOLYSIS- oxidation of glucose to pyretic acid; produces ATP and reduces NAD+ to NADH PENTOSE PHOSPHATE PATHWAY- NADP+ to NADPH ENTNER_DOUDOROFF PATHWAY- takes glucose and produces two molecules of NADPH and one of ATP KREBS CYCLE-produces some ATP by substrate level phosphorylation, reduces electron carriers NAD+ and FAD and gives off CO2- NADH and FADH2 ELECTRON TRANSPORT CHAIN- produces a great deal of ATP by oxidative phosphorylation

Describe how lipids and proteins undergo catabolism.

Urea --Urease--> NH3 + CO2 Protein ---Extracellular proteases--> Amino acids ----Deamination, decarboxylation, dehydrogenation, desulfurization--> Organic acid--> Krebs cycle

Compare and contrast aerobic and anaerobic respiration, especially in terms of energy yield.

aerobic - the final electron acceptor is O2; anaerobic - the final electron acceptor is an inorganic molecule other than O2, or rarely, an organic molecule; yields less energy than aerobic because only part of the krebs cycle operates under anaerobic conditions Electron acceptor: NO3- , product: NO2-, N2 + H2O electron acceptor: SO4-, product: H2S + H2O Electron acceptor: CO3 2-, product CH4 + H2O