This pertains to the structure of proteins. Secondary structures are stabilized by the presence of hydrogen bonds. The common types of secondary structures of proteins are the alpha helix and the beta sheets, each performing different functions. 
Primary structure of protein is the peptide molecule comprised of peptide bonds. Once these peptide grows long enough, it will either be arranged into alpha helices or beta sheets stabilized by hydrogen bonds and this is the secondary structure. Once there is protein folding involved in the secondary structure of protein, then the folded protein is called the tertiary structure (or a protein subunit). When protein subunits come together to perform a specific function, then that is the quaternary structure.
Attached is a figure concerning the protein structures.
 
        
        
        
Answer:
Wind can change landforms by weathering, erosion and deposition. Fast water, with a lot of energy, can erode a lot of sediment.
 
        
             
        
        
        
Answer:
Each parent carries a gene for green (y) and a gene for yellow (Y). Place one parent's genes along the top of the Punnett square and the other parent's genes along the left side. Copy the genes down the columns and across the rows. Each of the four squares now shows a possible genotype combination
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Answer:
The correct answer is - through facilitated diffusion and active transport.
Explanation:
Glucose is a six-carbon sugar molecule that is directly utilized by cells to provide energy. A glucose molecule is large enough to go through a cell membrane with simple diffusion.  
Cells help glucose molecules to cross the cell membrane through facilitated diffusion and active transport. Active transport is of two types primary and secondary active transport to help the glucose molecule to cross the membrane.
Thus, the correct answer is - through facilitated diffusion and active transport.
 
        
             
        
        
        
Answer:
D they are both because they can be both metals and no metals
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