Chapter 10 Flashcards
Metabolites
The small molecules that are intermediates in the degradation or biosynthesis of biopolymers.
Anabolic Reactions
Those responsible for the synthesis of all compounds needed for cell maintenance, growth, and reproduction
Make simple metabolites: amino acids, carbs, coenzymes, nucleotides, and fatty acids.
Larger molecules: proteins, polysaccharides, nucleic acids, and complex lipids.
Catabolic Reactions
Degrade large molecules to liberate smaller molecules and energy.
Amphibolic Reactions
Involved in both anabolic and catabolic pathways.
Metabolic Pathway
A series of reactions where the product of one reaction becomes the substrate for the next reaction.
Some may only be two steps, others may be a dozen.
Linear metabolic Pathway
A series of independent enzyme catalyzed reactions in which the product of one reaction is the substrate for the next reaction in the pathway.
Cyclic metabolic Pathway
A sequence of enzyme catalzyed steps, but the sequence forms a close loop, so the intermediates are regenerated with every turn of the cycle.
Spiral metabolic pathway
The same set of enzymes is used repeatedly for lengthening or shortening a given molecule.
Intracellular Environments of pathways
Reactions proceed at moderate temperatures and pressures, at rather low reactant concentrations, and at close to neutral pH.
Reason for multistep pathways
One reason for multistep pathways is the limited reaction specificity of enzymes. Each active site catalyzes only a single step of a pathway.
The synthesis of a molecule – or its degradation therefore follows a metabolic route defined by the availability of suitable enzymes.
Another Reason for multistep pathways
To control energy input and output. Pathways for the biosynthesis of molecules require the transfer of energy at multiple points.
