3A)Amino acids-peptide
3B)Enzymes–speed up
3C)Active sites–substrate 
3D)Unchanged
3E)[follow the instructions given]
4A)DNA—RNA
4B)Nucleotide—Deoxyribose–Phosphate–Nitrogen base
4C)DNA
4D)Thymine–Adenine—Cytosine–Guanine
4E)Hydrogen bonds
        
             
        
        
        
Answer:
A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mechanism.
Explanation:
A cell wall is a rigid, semi-permeable protective layer in some cell types. This outer covering is positioned next to the cell membrane (plasma membrane) in most plant cells, fungi, bacteria, algae, and some archaea.
 
        
                    
             
        
        
        
Answer:
B) Krebs cycle (citric acid cycle)
Explanation:
Glycolysis breaks glucose into two pyruvate molecules. Pyruvate is decarboxylated into acetyl CoA and the reaction occurs in the matrix of mitochondria. In the mitochondrial matrix, acetyl CoA enters Kreb's cycle and is broken down into CO2 and H2O. For one molecule of acetyl CoA, two molecules of CO2 are released as a by-product. Therefore, out of three carbon atoms of pyruvate, two are released as CO2 during Kreb's cycle.
 
        
             
        
        
        
Answer:
Explanation:
osmosis is the movement of water molecules from the region of higher concentration to the region of lower concentration down the concentration gradient.
some of the examples are root hair cells as they absorb water molecules from the soil and are low in concentration compare to the soil. so osmosis takes place