BackMicrobiology Metabolism and Photosynthesis Study Guide
04:21
Terms in this set (34)
refers to enzyme-regulated energy-requiring reactions that build complex molecules from simpler ones.
is the breakdown of complex molecules into simpler ones, releasing energy.
is the energy required to start a chemical reaction.
binds to the active site of an enzyme, blocking substrate binding.
binds to an allosteric site, changing enzyme shape and reducing activity.
use light energy to fix carbon dioxide into organic compounds.
obtain energy by oxidizing inorganic molecules and fix CO2 for growth.
obtain energy and carbon from organic compounds.
use light for energy but require organic compounds as carbon sources.
is the protein portion of an enzyme, inactive without its cofactor.
is a non-protein component (metal ion or organic molecule) required for enzyme activity.
is an organic cofactor that assists enzyme function, often derived from vitamins.
is the active enzyme consisting of apoenzyme plus its cofactor(s).
can denature enzymes, altering their shape and reducing or stopping their activity.
occurs when the end product of a pathway inhibits an earlier enzyme to regulate the pathway.
Sulfa drugs act as competitive inhibitors by mimicking substrates and blocking enzyme active sites.
ATP is produced by substrate-level phosphorylation, oxidative phosphorylation, and photophosphorylation.
Glycolysis produces 2 pyruvate, 2 ATP, and 2 NADH. Oxygen is not consumed.
It generates 5-carbon sugars for nucleotide synthesis and provides reducing power as NADPH.
The Krebs cycle produces CO2, NADH, FADH2, and ATP. It turns twice per glucose and occurs in the mitochondrial matrix in eukaryotes and cytoplasm in prokaryotes.
Energy in NADH and FADH2 is converted to ATP via the electron transport chain and oxidative phosphorylation.
CO2 is produced in the Krebs cycle; O2 is consumed in the electron transport chain; H2O is produced at the end of the electron transport chain.
The electron transport chain cannot function without O2 as the final electron acceptor in aerobic respiration.
Fermentation regenerates NAD+ from NADH, allowing glycolysis to continue without oxygen.
Common fermentation by-products include ethanol and lactic acid.
Fermentation can be tested by detecting acid or ethanol production using pH indicators or specific chemical tests.
Fats are broken into glycerol and fatty acids; glycerol enters glycolysis as dihydroxyacetone phosphate, fatty acids undergo beta-oxidation to acetyl-CoA for Krebs cycle.
Proteins are first deaminated, then their carbon skeletons enter glycolysis or Krebs cycle for catabolism.
Carbon fixation is the process of converting CO2 into organic molecules during photosynthesis.
Cyclic photophosphorylation produces ATP only; electrons return to chlorophyll.
Non-cyclic photophosphorylation produces ATP, NADPH, and releases O2.
Both systems balance ATP and NADPH production to meet cellular energy and reducing power needs.
The Calvin-Benson cycle uses ATP and NADPH to fix CO2 into a 3-carbon sugar (G3P) for carbohydrate synthesis.
Intermediates from catabolic pathways are used to synthesize triacylglycerides, amino acids, polysaccharides, and nucleosides.