Answer:
Melanin is the not the only pigment that can influence skin color. Carotene, found in plants such as carrots, can accumulate in the stratum corneum, and hypodermis can give the skin an orange hue.
Answer:
Reactions require an input of energy to initiate the reaction; this is called the activation energy (EA).
Activation energy is the amount of energy required to reach the transition state.
The source of the activation energy needed to push reactions forward is typically heat energy from the surroundings.
For cellular reactions to occur fast enough over short time scales, their activation energies are lowered by molecules called catalysts.
Enzymes are catalysts
