midterm Flashcards
difference between covalent and ionic bonds
-covalent: two atoms that have the same charge (nonmetal and nonmental), share elctrons
-ionic: two atoms that are differenty charged (metal and nonmetal), steal electrons
how do antacids work (based on your knowledge of buffers and the pH system)?
-work like buffers to absorb the excess H+ ions in order to bring u the pH and level out the acidity to make the stomach in normal pH range
-low pH = high acidity = excess H+
-high pH = high basity = excess OH -
six properties of water
-solvency
-cohesion and adhesion
-high surface tension
-high heat capacity
-high heat of vaporization
-varying density
explain how solvency (in water) is important to life
-Due to polarity and H-bonding, water dissolves many substances
-universal solvent
-important to majority of organisms on earth
explain how cohesion and adhesion (in water) is important to life
-Allows water to be excellent transport system both inside and outside of living organisms
-Contributes to water transport in plants
explain how high surface tension (in water) is important to life
-allows certain organisms to float, move, and even live on the water’s surface
explain how high heat capacity (in water) is important to life
-The many hydrogen bonds linking water molecules allow water to absorb heat without greatly changing its temperature.
-Temperature of water rises and falls slowly
-Helps humans/organisms composed of water be able to maintain body temp
explain how high heat of vaporization (in water) is important to life
-Takes a great deal of energy to break H bonds for evaporation.
-Heat is dispelled as water evaporates
-helps water reserves stay and not evaporate totally in the sky
explain how varying density (in water) is important to life
-Unlike other substances, water expands as it freezes.
-Ice floats rather than sinks.
-It makes life possible in water.
-Ice acts as an insulator.
difference between organic and inorganic molecules
-organic must have carbon and hydrogen
basic characterisitcs of all cells
-plasma membrane
-cytoplasm
-cytoskeleton
-ribocomes
-genetic information
-can have cell wall
differences between prokaryotes and eukaryotes
-pro: no membrane bound organelles or nucleus (do have cytoplasm, ribosome, plasma membrane, nucleiod instead of nucleus)
-eu: nucleus, all membrane bound organelles
how might knowing the structure of an active site of an enzyme allow you to build a drug to regulate a metabolic pathway?
-specifically shape the molecule to compete with substrate for enzyme’s active site and bond to it
-acts like feedback inhibition
-regulates how much product is made by restricting substrates from bonding to active site and therefore reaction from occuring
how do enzymes speed up chemical reactions?
-by bringing reactants (substrates) together so they can bind, forcing them to react with each other
-by lowering activation energy required to start a reaction
-instead of relying on molecules to naturally and randomly bump into each other we rely on enzymes to force the reaction to happen
how are cellular respiration and photosynthesis connected?
-molecules are cycled through both
-photosynthesis is chlorplasts taking water, carbon, and making them into carbohydrates using colar energy
-cell respiration is mitchondria breakidng down carbs to create energy in the form of ATP
why do broad thin leaves provide an advantage for photosynthesis?
-broad thin leaves allow for more surface area to be exposed to teh sun to absorb solar energy
-thinnes allows their voluem to be limited so the process of transporting molecules is quicker
why is water needed in the light reactions?
-after energized electrons are passed of to the electron acceptor they need to be replaced
-H2O is broken down to provie these replacement elecrons
-H+ ions are also produced from photolysis are needed to reduce NADP+ and make it accept H+ ions to create NADPH
