BIOSC 0160 Lecture 7: How Genes Work
Document Summary
Metabolic pathways series of chemical reactions occurring in a cell. Catabolic (breaks down complex molecules into simpler molecules) Anabolic (creating complex molecules from simpler molecules: i. e. glycolysis, degradation of polymers to monomers, i. e. production of proteins. Enzymes catalyze steps in a metabolic pathway. *** if enzyme catalyzing a particular step doesn"t work, the substrate of that step will accumulate in the cell. Minimal medium contains minimum nutrients possible for growth; generally without presence of amino acids so that cells must make them on their own. Complete medium contains complete set of nutrients necessary for cell growth. If mutant cell with a defect at one step of a pathway is grown on a medium supplemented by metabolic intermediate downstream of defective step, the mutant cell will grow. If enzyme 3 is a mutant, then supplementing the medium with d and e then the pathway will continue because enzyme 4 will continue to make substrate e from the supplemented d.