Answer:
C. Coupled reactions establish an electrochemical gradient across a membrane.
Explanation:
- During cellular respiration in mitochondria, and during photosynthesis in chloroplasts, the electron transport chain requires a proton gradient to pump protons across the membrane by active transport. 
- Protons flow back across the membrane by facilitated diffusion through ATP synthase, which utilizes them to phosphorylate ADP to ATP.
- This process of ATP synthesis by harnessing the elctrochemicaal gradient geenrated by the diffusion of protons across the biological membrane through ATP synthase is called chemiosmosis.
 
        
             
        
        
        
Answer:
Nitrogen about 77 percent of the atmosphere is composed of nitrogen 
 
        
                    
             
        
        
        
Answer:
Which of the following water filtration methods requires the use of a membrane or filter? Reverse Osmosis
Explanation:
Reverse Osmosis has to do with a solute using a membrane that allows such with the help of hydrostatic pressure
 
        
                    
             
        
        
        
Answer: I think it’s D. Pls don’t bash me if it’s wrong
        
                    
             
        
        
        
Heat must be added to make a reduction reaction.