Answer:
The correct option is 3. "At pH 6.5 the enyzme is 50% active" 
Explanation:
For the titratable group to be protonated and cause the enzyme to be in the active state, it needs to have gained a hydrogen cation (H+). In order for that to happen, there must be enough hydrogen cations in the environment of the enzyme, and hence, an acidic pH is required in this case.
 
        
             
        
        
        
The correct answer is - A. A few centimeters a year.
Earth's crustal plates move very slowly, between 2 cm and 5 cm (depending on the plate) annually. This is the reason why it takes millions of years for them to significantly change their position, and with it the appearance of our planet. These crustal plates are slowly moving around the planet because they are powered by flow in the interior mantle.
 
        
             
        
        
        
Work is said to be done when an object moves due to a force applied. Work is calculated by multiplying the force applied and the distance traveled due to the force. It is expressed as:
W = Force x distance
W = 84 J = F (7.0 m)
F = 12 N
Hope this answers the question.
        
                    
             
        
        
        
Answer:
complex carbs you should eat more of whole grains