1. use model 1 to show which atoms are present in each type of molecule by listing the symbol for each atom included. carbohydrate has been done for you. a. carbohydrate— c, h, o c. amino acid—b. lipid— d. nucleic acid—

Amino acids C, H, O, and N

Lipids C,H,O, and also N and P

Nucleic acids C,H,O,N and P

Explanation:

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.