6 Energy-Driven Inventions
6.1 Living Systems Require a Flow of Energy
In a phrase, how do physicists define “energy”? the ability to do work
The physicist’s definition of energy is not for use in defining ene
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6 Energy-Driven Inventions
6.1 Living Systems Require a Flow of Energy
In a phrase, how do physicists define “energy”? the ability to do work
The physicist’s definition of energy is not for use in defining energy changes within a living cell. Comprehensive enough
How would a cell biologist define “energy”? the ability to make specific changes occur
List 5 major sorts or categories of energy change within the cell. Fig 6.2. Biosynthesis, Movement, Concentration, electrical potential, heat
Sometimes the cell pumps substances against diffusion forces that would otherwise carry those substances the other way. What term/phrase would we give to this pumping process? Energy of concentration
On a cold day, which of the following processes do your cells depend on to maintain an operating temperature of 37 degrees Celsius?
a. muscle contraction
b. shivering
c. respiration energy production
d. metabolic heat generation
e. all of the above e
6.2 Laws of Energy Flow in the Living World
is freely convertible from one form to another but can never be created or destroyed in normal processes. Energy, energy
(That means that in nature, as energy freely changes from one form to another, the total amount of energy stays constant.)
Thus, a lit match cannot continue to burn when the wood of the match stick is consumed. This statement illustrates what general law of energy flow? law of conservation of matter and energy
Systems that convert energy from one form to another are not 100% efficient, thus the amount of useful energy . decreases
This is because, in cars and in living things, energy conversion is inefficient, with much energy being lost in the form of useless . Fig 6.4 Heat (useless energy)
So, when your car engine burns the octane in gasoline, in what form does at least 50% of the energy of the octane end up? heat
In a crowded, unventilated room, what causes the temperature to rise? Heat buildup due to burning of glucose in body
What form of energy do producers use when they set about to generate chemical energy—the energy of C―H and C―O―H bonds? solar
Thus, a producer organism is called a “producer” because it converts solar energy to usable . Fig 6.5 “Energy In” Chemical energy
6.3 Energy Flows in Chemical Reactions
Existing chemical bonds between atoms are broken and new ones are formed between different atoms. In the broadest sense this is the definition for a
. Chemical reaction
Write out an example of a chemical reaction using names and symbols of reactants and products with an arrow between them. 2H2 + O2 2H2O
Whenever chemical bonds are broken, energy is . Whenever chemical bonds form, energy is . (Characteristic #1) Required Given off
Does an endergonic reaction require the input of energy, or does it give off energy? (Characteristic #1) Requires input
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