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biologyfinalexamreview

The answer is in the membrane permeability ie can

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The answer is in the membrane permeability i.e. can solutes cross? Osmosis across the plasma membrane: important role in the lives of cells Effects of osmosis on red blood cells placed in various solutions: Cells placed into a hypertonic solution lose water and shrivel Cells placed into a hypotonic solution gain water and swell, or even burst (and die) Cells in isotonic solutions remain unaffected Blood plasma (liquid) must always stay isotonic Osmosis across the plasma membrane: important role in the lives of cells Effects of osmosis on plant cells: - Water flows into cytoplasm, then central vacuole, because they are more concentrated than the extracellular fluid Water builds up in the central vacuole creating turgor pressure
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Chapter 6: Energy: forms (potential, kinetic) - Chemical bonds contain potential energy o stored energy not being used - Breaking chemical bonds releases kinetic energy o energy of movement/motion o light (movement of photons) o heat (movement of molecules) o electricity (movement of charged particles) - Endergonic vs. exergonic - Exergonic reactions release energy (output) - Endergonic reactions require an input of energy Reactants vs. products - Chemical reactions convert reactants into products - Reactants (starting) à Products (ending) Enzymes & catalysts, activation energy - All can be “jump started” or sped up with enzymes - Enzymes = catalysts , which act by lowering activation energy, thereby speeding up a reaction - Enzymes make reactions occur fast enough Metabolism control Enzymes regulate all chemical reactions in cells Cells can control their own metabolism (rate of chemical reactions) by controlling enzymes Cells can make fewer or make more enzymes Cells can inactivate existing enzymes if they’re no longer needed, or activate them when needed Effects of pH and temperature on enzymes, denaturation - Enzymes are affected by environment o Enzymes = proteins, which are folded into complex structures to function o pH & temperature can alter this folding ( denaturation ) - If pH is too high (basic) or too low (acidic), enzymes become denatured - Temperature: o Low temperatures slow down (but don’t necessarily stop) enzymes o Raising temperatures speed up enzymes o Extremely high temperatures = denaturation - Chapter 7: *Be familiar with figure 7-3 Photosynthesis: overall “equation”
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- Photosynthesis = process by which solar energy is trapped & stored as chemical energy in the bonds of a sugar (glucose) molecule - endergonic - reaction) - 6 CO 2 + 6 H 2 O + light energy à C 6 H 12 O 6 + 6 O 2 carbon water sunlight glucose oxygen dioxide (sugar) Light reaction vs. Calvin cycle - During the Calvin cycle (light-independent): o Enzymes in the stroma use CO 2 and chemical energy from ATP & NADPH to make glucose o Inactivated ADP & NADP = “waste” but are then recycled o ATP + NADPH + CO 2 à glucose, ADP, & NADP o “Photo” part = capture of sunlight in the thylakoids (light reactions) o “Synthesis” part = the Calvin cycle, which synthesizes sugar o These reactions are highly oversimplified o
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