Chapter 5: Essential Concepts Of Metabolism Flashcards
Anabolism
Use energy to build bigger molecules from smaller molecules
- amino acids to proteins
Catabolism
Taking a larger molecule and breaking it down to its basic components, releasing energy to be used by the cell
- protein to amino acids
ATP
Adenosine triphosphate
- cells main source of energy
Oxidation
Loss of electrons
- loss of energy (exothermic)
- loss of hydrogen, gain an oxygen
Reduction
Gain of electrons
- gain hydrogen and energy (endothermic)
- loss of oxygen
Autotrophs
Make their own food
- use CO2 as their carbon source
Photoautotrophs
Use light as their energy source
Chemoautotrophs
Use inorganic compounds (iron, sulfur) as their energy source
Heterotrophs
Don’t make their own food, use organic compounds as carbon source
Photo heterotrophs
Purple and green non sulfur bacteria
- somewhat rare
Chemoheterotrophs
Organic compounds are energy and carbon source
- all protozoans, fungi, animals
Metabolic pathway
Uses enzymes to turn molecules into other molecules
Enzymes
Proteins that are catalysts (speed up the rate of reaction without being used or changed)
- work by lowering activation energy
- substrates bind to active site and transform
Apoenzyme
Protein portion of enzyme (enough for some enzymes)
Coenzyme
Nonprotein, organic molecule that carries electrons (derived from vitamins)
- NADH/NAD+
- FAD/FADH2
Cofactor
Inorganic molecule that helps improve the fit to the active site
- Zn, Mg ions
Holoenzyme
Complete, functional enzyme
- some apoenzymes are holoenzymes
- could be apoenzyme+cofactor+coenzyme
Competitive inhibition
Molecule (competitive inhibitor) is competing with a substrate for the active site on an enzyme
- sulfa drugs (inhibit PABA from binding to enzyme to be converted into folic acid (needed for bacteria))
Non competitive inhibition
Molecule binds to another site (allosteric site) and distorts the active site so substrates can’t bind
- irreversible, ex. Poisons like mercury inhibit enzymes
Influences on reaction rate
- Temperature: ^ leads to ^ enzyme activity up to optimum temperature
- pH: optimum ~7
- substrate: ^ substrate, ^ rate
- product: ^ product, v rate
- enzyme: ^ enzyme, ^ rate
Fermentation
Anaerobic process that reoxidizes NADH to allow NAH+ to be used in glycolysis
- doesn’t produce ATP
- substrate: pyruvate
- multiple pathways (propionic, butyric-butylic, butanediol)
Homolactic pathway
Produces lactic acid
Alcoholic pathway
Produces ethyl alcohol
Aerobic respiration
Glycolysis + krebs + ETC
- allows extraction of energy from high energy electron carriers to make ATP
