Chapter 5: Energy & Enzymes Flashcards
Energy is
Capacity to do work
Work is
Move matter against an opposing force
Kinetic energy
The energy of movement
Heat is a form of
Kinetic energy because it comes from the movement of molecules
Light is also a form of
Kinetic energy
Potential energy
Stored energy, often related to location or position
Chemical energy
Energy stored in chemical bonds
Laws of Thermodynamics
Energy cannot be created or destroyed, only shift forms
Conversion of energy will result in
Some loss of energy in the form of heat
Entropy & Biology
Entropy (disorder) tends to increase as energy transformations occur (2nd law)
Need to put in constant energy to
Keep life going
Metabolism releases
Heat energy
Less than 25% of gas in the tank
Actually powers your car
Metabolism
The sum total (similar to net) of all chemical reactions in a living organism
Anabolic
Putting molecules together, requiring energy input
Reactant + free energy =
Products
Catabolic
Breaking down molecules, releasing energy
Reactant =
Product + free energy
ATP
Adenosine triphosphate: The energy form used to support life processes
Energy is stored as
Phosphate bonds (unstable, high-energy)
ATP (Resuable)
Lose a phosphate group, gain it back, repeat.
Energy source: Solar energy
Life depends on the conversion of 1% of the energy released by the sun
Exceptions:
Chemosynthetic organisms living around deep sea hydrothermal vents
Conversion process is called
Photosynthesis
Autotroph (self-feeding)
Sustain themselves without eating or decomposing otther organisms (they make organic molecules from inorganic raw materials) (aka producers)
Heterotroph (other-feeding)
Sustain themselves by eating or decomposing other organisms (aka consumers)
Many protein are
Enzymes
Enzymes
Molecules that catalyze reactions (increase the rate of reaction)
An enzyme has an
Active site that matches a particular substrate molecule
Regulation
Inhibitors blocks enzyme activity
Competitive inhibitor
Directly blocks active site
Noncompetitive inhibitor
Does not fill the active site, but changes the active site shape making it unusable
Feedback loops: Enzymes are often used to
Regulate metabolic pathways, and they are very sensitive to low substrate concentration
