Not sure what you mean but here's what i think
1.They are substrate-specific, because it's a lock-and-key mechanism.
2. They are re-used
3. They can catalyze reactions
4. They decrease activation energy
5. They are proteins by nature.
 
        
                    
             
        
        
        
Answer:
The correct answer is orange.
Explanation:
Carotenoids are the accessory pigments generated by plants.Carotenoid belongs to terpinoid family of secondary metabolites.Many vegetables such as pumpkin,tomato, carrot  have specific color combination only due to the presence of carotenoids.
       Carotenoid is responsible for orange,yellow and red coloration of various vegetables such as pumpkin,carrot,tomato etc.
 
        
                    
             
        
        
        
<u>ANSWER:</u>
The correct option is C: Skin that blends with green plants. Most animals in rain forests are green so that they can camouflage and appear like plants.
<u>EXPLANATION:</u>
- Adaptation is the way in which animals survive in different climatic conditions and different regions. In rain forests, to protect themselves and to find food, most animals are green in colour. 
- This prevents the animals from being spotted easily and therefore they are protected from hunters and other animals that eat them. This way, the animals can also find their prey and catch it easily.