7 Energy + Metabolism Flashcards
Energy
Capacity to do work (transfer of energy to object, cause to move)
Chem Energy
Contained in molecules + released by chem reactions
Calorie
1 cal - amount of energy needed to cause temp. of 1 gram of water from 14.5 c - 15.5 c
What provides chem energy?
Carbs, lipids, proteins
ATP
Accepts & briefly stores energy released from 1 chem reaction & transfers energy to next
Potential Energy
Stored energy
Includes chem energy in bonds, binding atoms together in molecules
Kinetic energy
Energy of movement
Includes light, heat. electric
Movement of objects
1st law of thermodynamics
Energy can neither be made nor destroyed
Can be converted from one form to another
2nd law of thermodynamics
When energy converted from one form to other - amount of useful energy decreases - energy lost from reactions in form of heat
Entropy
Tendency in universe to loss of complexity, orderliness, useful energy & a concurrent increase in randomness, disorder, less useful energy
Original energy source
Fusion reactions of sun - sustain life on earth
Photosynthetic organisms
Use solar energy - synthesize complex molecules & maintain orderly structures
Chemical reactions
Process - forms/breaks chemical bonds that hold atoms together
Convert 1 set of chemical subs & reactance into products
Exergonic
Chemical reaction releases free energy (heat) - spontaneous - negative free energy
Endergonic
Chemical reaction needs input energy - NOT spontaneous - positive free energy
How to determine if exergonic or endergonic
Calculating change in free energy
Free energy
Can do work when temp. & pressure uniform
Coupled reactions
Many cell reactions are coupled so energy released from exergonic reactions may be used to drive endergonic reactions
ATP
Molecule cells use ATP to temporarily store & transfer energy - stored in bond between 2nd & 3rd phosphate group
NOT stored by cells, always utilized
Metabolism
Sum total of chemical reactions for biosynthetic & energy harvesting processors
