Enzymes are proteins, and their functions are determined by their complex structure. The way enzymes work can also be shown by considering the energy changes that take place during a chemical reaction. We shall consider a reaction where the product has a lower energy than the substrate, so the substrate naturally turns into product (in other words the equilibrium lies in the direction of the product). Before it can change into product, the substrate must overcome an ‘energy barrier’ called the activation energy (EA). The larger the activation energy, the slower the reaction will be because only a few substrate molecules will by chance have sufficient energy to overcome the activation energy barrier.
How do enzymes affect the activation energy of the reactants?

Interneurons: Neurons of the peripheral nervous system; send signals back and forth between the brain or spinal cord and the limbs and sense organs
Sensory neurons: Neurons that transmit messages to the brain and the spinal cord from the sense organs
Motor neurons: Neurons that carry commands from the brain and spinal cord to the muscles and glands
Chemical exchange: the means by which neurons send and receive electrical signals associated with smell and taste
Mechanical stimulus: the means by which neurons send and receive electrical signals associated with sight, sound, and touch

Genetically modified crops and livestock offer the possibility of greater yield and food quality, reductions in pesticide use, and higher profits for agricultural businesses. They are viewed by some as a way to help reduce world hunger by increasing food production and reducing losses to pests and varying environmental conditions. Each year, industrial agriculture relies more heavily on genetically modified crops. There are some concerns about our increasing use of genetically modified crops and livestock, including their safety for human consumption and their effects on the environment.

Based on the passage above, if genetically modified crops were to be banned, what could be the largest negative impact to humans?

Battery companies make impressive claims about how long their batteries will last. A student decided to test the running time of different batteries to determine which battery lasts the longest. The student tested 6 different batteries, 4 brand name and 2 generic, using flashlights. The results show that the battery referred to as Name Brand A lasted the longest, with 101 hours of runtime:

It could be argued that this experiment was not set up using proper experimental protocol. What would need to change in the experiment for the results to be valid?

It could be argued that this experiment was not set up using proper experimental protocol. What would need to change in the experiment for the results to be valid?

The Ionic Product of Water, \({K_{\rm{w}}}\), is the equilibrium constant for the reaction in which water undergoes an acid-base reaction with itself.
\({K_{\rm{w}}} = \left[ {{H_3}{O^ + }_{(aq)}} \right]\left[ {O{H^ - }_{(aq)}} \right] = {10^{ - 14}}at25{}^oC\)
The value of  K_w increases almost 75 times when temperature is increased from 0°C to 100°C .
According to the above equation, what type of behavior is shown by water?