AP Biology - Unit 3 Quiz 1

Anabolic Pathway

pathways that consume energy to build complicated molecules from simpler compounds

Catabolic

pathways that release energy by breaking down complex molecules into simpler compounds

Cofactors

non-protein molecules that assist enzyme function;  inorganic co-factors consist of metals;  can be bound loosely or tightly;  holoenzyme (enzyme with co-factor attached)

Non-competitive Inhibitors

binds to an area other than the active site (allosteric site), which changes the shape of the active site preventing substrates from binding 

Competitive Inhibitors

reduce enzyme activity by blocking substrates from binding to the active site;  inhibition can be reversed with increased substrate concentration;  Competitive inhibitors “competes” with substrate

Activation energy

the minimum amount of energy required to start a chemical reaction. Enzymes lower the amount of energy needed for a reaction to occur.

1st Law of Thermodynamics

energy cannot be created or destroyed; energy can be transferred or transformed

ex. the chemical (potential) energy stored in the nut will be transformed into kinetic energy for the squirrel to climb the tree

Kinetic energy

energy associated with motion

Potential energy

stored energy

Free energy

energy that is available to do work at constant pressure and temperature

Exothermic

releases energy, typically heat, into the surroundings

Endothermic

absorbs energy, typically heat, from its surroundings

ATP (Adenosine Triphosphate)

molecule that organisms use as a source of energy to preform work

How is ATP used for energy?

ATP couples with exergonic reactions to endergonic reactions to power cellular works

Organisms obtain energy by breaking the bond between the 2nd and 3rd phosphate in a hydrolysis reaction

Phosphorylation: the released phosphate moves to another molecule to give energy

Temperature (effect on enzyme function)

the rate of enzyme activity increases with temperature (due to collision) up to a certain point. After a certain point the enzyme will denature

pH (effect on enzyme function)

being outside the normal pH range can cause hydrogen bonds in the enzyme to break, changing the shape of the concentration

Substrate Concentration (effect on enzyme function)

increased substrate concentration increases activity because more substrate molecules are available to bind to the enzyme’s active site

Salinity (effect on enzyme function)

disrupts the enzyme’s structure and function. Low salinity can cause charged amino acid side chains to attract each other, leading to denaturation and aggregation

Major Ideas about Lab

The effect of enzyme concentration, temperature, pH, and substrate concentration

Increased enzyme concentration increases rate of reaction