BILD 1 Study Guide - Midterm Guide: Sterol, Scanning Electron Microscope, Paramecium
Document Summary
Life organized into a hierarchy of structural levels: atoms -> molecules -> cells: have emergent properties: non-life -> life. Essential elements: naturally occurring elements necessary for life: we have 25 essential elements, plants have 17. O, c, h, n make up 96% of elements. Chemical bonds: atoms held together through bonds: covalent bonds: between atoms of same/different element; share electrons to (cid:272)o(cid:373)plete oute(cid:396) shell. Molecular shape determines how biological molecules recognize/respond to one another: ex: opiates (morphine) and naturally produced endorphins have similar effects because their shapes are similar and they bind the same receptors in the brain. Chemical reactions make/break bonds: # atoms from reactants to products do not change. 4 ways that carbon skeletons can vary length, double bond position, branching, presence of rings. Molecules of life: carbohydrates, lipids, proteins, and nucleic acids. Synthesis and breakdown of polymers into monomers: synthesize: dehydration reaction (taking away water, breakdown: hydrolysis (adding water)
