Reinforcement Exercise on Biological Macromolecules - Free Printable

Problem: Reinforcement - Biomolecules

The task is to fill in the blanks using the provided terms from the word bank. Let's solve each question step by step.

---

#### Word Bank:
- cellulose
- fatty acids
- organic
- energy
- macromolecules
- enzyme
- glucose
- starch
- nucleic acids
- hagfish
- monomers
- chitin
- carbohydrates
- nucleotides
- phospholipids
- amino acids

---

1. Polymers are made of individual subunits called _________.

- Explanation: Polymers are large molecules composed of repeating units called "monomers." For example, proteins are polymers made of amino acid monomers, and carbohydrates are polymers made of sugar monomers.
- Answer: monomers

---

2. Chains of glucose make up _________.

- Explanation: Glucose is a simple sugar (a monomer), and when it forms chains, it creates more complex carbohydrates. Common examples include starch (in plants) and glycogen (in animals).
- Answer: carbohydrates

---

3. Molecules that make up living things and contain carbon are called _________ molecules.

- Explanation: Organic molecules are those that contain carbon and are essential for life. Examples include carbohydrates, lipids, proteins, and nucleic acids.
- Answer: organic

---

4. An aquatic animal that makes a protein-based slime _________.

- Explanation: The hagfish is an aquatic animal known for producing a thick, protein-based slime as a defense mechanism against predators.
- Answer: hagfish

---

5. A carbohydrate that makes up the cell walls of plants: _________.

- Explanation: Cellulose is a structural carbohydrate found in plant cell walls. It provides strength and rigidity to plant cells.
- Answer: cellulose

---

6. A carbohydrate that makes up the exoskeleton of insects: _________.

- Explanation: Chitin is a carbohydrate-like substance that forms the exoskeleton of insects and other arthropods. It provides structural support.
- Answer: chitin

---

7. Lactase is an _________ that breaks down milk sugar.

- Explanation: Lactase is an enzyme, a type of protein that catalyzes chemical reactions. In this case, lactase breaks down lactose (milk sugar) into simpler sugars like glucose and galactose.
- Answer: enzyme

---

8. The cell membrane of all cells is made of _________.

- Explanation: The cell membrane is primarily composed of phospholipids, which form a bilayer structure. Phospholipids are amphipathic molecules with hydrophilic heads and hydrophobic tails.
- Answer: phospholipids

---

9. Nucleic acids are made of individual subunits called _________.

- Explanation: Nucleic acids (DNA and RNA) are polymers made of smaller units called nucleotides. Each nucleotide consists of a sugar, a phosphate group, and a nitrogenous base.
- Answer: nucleotides

---

Final Answers:

1. monomers
2. carbohydrates
3. organic
4. hagfish
5. cellulose
6. chitin
7. enzyme
8. phospholipids
9. nucleotides

---

Boxed Final Answer:
\[
\boxed{
\text{1. monomers, 2. carbohydrates, 3. organic, 4. hagfish, 5. cellulose, 6. chitin, 7. enzyme, 8. phospholipids, 9. nucleotides}
}
\]