Educational worksheet on lipids, covering types, structures, and characteristics with diagrams and fill-in-the-blank exercises.

Problem Analysis:

The task involves identifying and describing the types of lipids (triglycerides, phospholipids, and steroids) and their structures. The worksheet provides diagrams and a table to fill in the missing information.

Solution:

#### Section 1: Introduction
1. Built up from carbon, hydrogen, and oxygen. But proportion of oxygen is lower than in carbohydrates.
- Lipids are primarily composed of carbon, hydrogen, and oxygen. However, the proportion of oxygen in lipids is much lower compared to carbohydrates, making them less hydrophilic.

2. Large biological molecule that does not consist of polymers but it is called macromolecule.
- Lipids are considered macromolecules because they are large biological molecules, even though they do not form polymers like proteins or carbohydrates.

3. Hydrophobic compounds that insoluble in water but soluble in solvents.
- Lipids are hydrophobic (water-repelling) due to their nonpolar nature. They are insoluble in water but soluble in organic solvents like alcohol or ether.

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#### Exercise 1.3 (a): Identify Types of Lipid
The exercise asks to identify the types of lipids shown in the diagrams and name them in the boxes provided.

1. First Diagram (Left):
- This diagram shows a triglyceride structure.
- A triglyceride consists of three fatty acid chains attached to a glycerol backbone via ester bonds.
- Name: Triglyceride (Fat & Oil)

2. Second Diagram (Middle):
- This diagram shows a general representation of lipid types, which includes triglycerides, phospholipids, and steroids.
- No specific type is depicted here, so this is just a placeholder for the concept of "types of lipids."

3. Third Diagram (Right):
- This diagram shows a phospholipid structure.
- A phospholipid has two fatty acid chains attached to a glycerol backbone, with a phosphate group attached to the third position of glycerol.
- Name: Phospholipid

4. Fourth Diagram (Bottom):
- This diagram shows a steroid structure.
- Steroids have a characteristic four-ring (tetra-cyclic) structure, with functional groups attached.
- Name: Steroid

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#### Table Completion
The table requires filling in details about the types of lipids, their structures, and characteristics.

| Types of Lipid | Structure | Characteristics |
|---------------------|-------------------------------------------------------------------------------|------------------------------------------------------------------------------------|
| 1. Triglyceride | - Consist of:<br> - Three molecules of fatty acids<br> - One glycerol molecule<br> - Bond: Ester bond | - Non-polar molecule which is insoluble in water.<br> - Has 2 types:<br> 1. Fat (solid state at room temperature)<br> 2. Oil (liquid state at room temperature) |

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Final Answer:

1. Introduction:
- Built up from carbon, hydrogen, and oxygen.
- Large biological molecule that does not consist of polymers.
- Hydrophobic compounds that are insoluble in water but soluble in solvents.

2. Exercise 1.3 (a):
- First Diagram: Triglyceride (Fat & Oil)
- Second Diagram: Types of Lipid
- Third Diagram: Phospholipid
- Fourth Diagram: Steroid

3. Table:
- Types of Lipid: Triglyceride
- Structure:
- Three molecules of fatty acids
- One glycerol molecule
- Ester bond
- Characteristics:
- Non-polar molecule which is insoluble in water.
- Has 2 types:
1. Fat (solid state at room temperature)
2. Oil (liquid state at room temperature)

Final Answer Boxed:
\boxed{
\text{Triglyceride, Phospholipid, Steroid}
}