Question

1. what are two functions of polysaccharides? give one example of each and explain where it can be found.

macromolecules – part 2

1. is the picture below representing a nucleotide or a nucleoside? what is the difference between them? label the components shown in the picture

a = _______________
b = _______________
c = _______________

1. complete the drawing below to represent the general structure of an amino acid (you can use the name of a functional group, instead of drawing all the atoms). how many different side chains (r groups) are there?

Explanation:

Question 4

1. Energy Storage: Polysaccharides like starch (in plants, e.g., potatoes) and glycogen (in animal livers/muscles) store energy. Starch is in plant cells for energy reserve; glycogen in animals for quick energy access.
2. Structural Support: Cellulose (in plant cell walls) and chitin (in insect exoskeletons/fungal cell walls) provide structure. Cellulose strengthens plant cells; chitin supports arthropod exoskeletons.

• Nucleoside vs. Nucleotide: A nucleoside has a nitrogenous base + sugar; a nucleotide has base + sugar + phosphate. The diagram (A=base, B=sugar, C=? If C is phosphate, it’s a nucleotide; if not, nucleoside. Assuming C is phosphate:
• Labeling: A = Nitrogenous Base (e.g., adenine), B = Pentose Sugar (e.g., ribose/deoxyribose), C = Phosphate Group.
• Difference: Nucleotides have a phosphate; nucleosides do not.

• Amino Acid Structure: Central carbon (C) bonded to: amino group ($-\text{NH}_2$), carboxyl group ($-\text{COOH}$), hydrogen ($-\text{H}$), and R - group (side chain).
• R - Groups: There are 20 different amino acid side chains (R - groups) in living organisms.

Answer:

• Function 1: Energy Storage

Example: Starch (found in plant cells, e.g., potato tubers) stores energy for plants.

• Function 2: Structural Support

Example: Cellulose (found in plant cell walls) provides rigidity to plant cells.

Question 5