Chapter 1 – Basis of Life
Ingestion – acquisition of food
Assimilation – building of new tissues from digested food
Monosaccharide – (carb) single sugar subunit
Polysaccharide – (carb) polymer, insoluble in water; ex: glycogen / cellulose
Lipids – (2:1 H/O ratio) 3 FA bonded to glycerol; chief means of food storage
· Major component of adipose tissue
· Steroids, waxes, carotenoids, porphyrins
Proteins - polymers of AA joined by peptide bond / 1* = AA sequence, 2* = folding (alpha beta)
· Hormones (ACTH & insulin), Enzymes, structural pro (collagen), transport (hemoglobin), antibodies
Enzymes – lower activation E & inc. rate of rxn / do not affect overall E
· Higher temp = inc enzyme action / optimal pH = 7.2 (except pepsin & pancreas)
· Competitive inhibitors compete w/ substrate for binding at ACTIVE site; can be overcome by adding more substrate; Vmax not affected
· Noncompetitive inhibitors bind at allosteric site; diminishes Vmax
Prokaryotes – bacteria, cell wall, NO nucleus, NO memb-bound organelles, ribosomes (no mem), mesosomes (invaginations of membrane)
Eukaryotes – cell wall in fungi & plants, nucleus, membrane-bound organelles
Centrioles – microtubule involved in spindle organization during cell division/ NO membrane
Centromere – near middle of eukaryotic chromosomes where spindle fibers attach
Lysosome – membrane bound, involved in ingestion / hydrolytic enzymes
Mitochondria – exhibit maternal inheritance desmosomes = “spot welds”; attach cells together and give cells mechanical strength (ex. skin cells)
Tight junctions = seal the spaces b/w cells and prevent cell leakage (ex. intestinal cells)
Gap junctions = allow cells to exchange nutrients and for molecular communication
Endosymbiotic Theory – mitochondria and chloroplasts originated as independent unicellular organisms living in symbiosis with larger cells
Fluid Mosaic – lipids and proteins are free to move back and forth fluidly;