2. Energy Basics
Potential energy: stored energy
Kinetic energy: energy of motion
Law of Conservation of Energy: energy can not
be created or destroyed, only changed from one
form to another
Law of Entropy:The expenditure of energy is
never perfectly efficient, or, it takes disorder to
make order, or, it takes energy to change energy
3. ATP
ATP is the energy molecule!
The three phosphate groups each have a
negative charge, so they don’t want to be
bound together
Therefore, each bond houses potential
energy, and each bond took energy to
make
ATP ADP + P
4. ATP
ATP is broken down into ATP and P,
then it is recycled to make ATP again
It goes through 10,000 or so cycles per
day!
5. Energy Flow
Sunlight captured by chloroplasts
Energy used to make carbohydrates
(glucose)
Glucose made into ATP
ATP used for functions
Also, plants make oxygen and use
carbon dioxide
6. Metabolic Pathways
Consecutive reactions that take one
thing and turn it into another, in a
series of steps
Enzymes help these steps happen more
quickly and easily
These ‘helpers’ are found throughout
biological activities and functions
7. Enzymes
Enzymes are small(ish) proteins that
bind to a substrate to act on it
They bind only at the active site
The active site changes shape slightly
when it binds, and this is what causes
the reaction to occur
8. Enzymes and Feedback
Enzyme-regulated reactions can get out
of control
Feedback inhibition occurs when either
the final product or a byproduct
competes with main substrate to bind to
the enzyme
9. Cell Transport
Passive: diffusion- molecules will spread
out to be evenly distributed in a solution
Osmosis: the diffusion of water across a
semipermeable membrane
Why you gargle with salt water
10. Osmosis
Because the cell membrane is not permeable to
most things, water is what diffuses across it
Isotonic: normal situation, conc of water
same on both sides
Hypotonic: cells gain water, conc of water
greater outside cell
Hypertonic: cells loose water, conc of water
greater inside cell
