2 min read
Lipids
Lipids are a group of biological molecules that include fats and oils and are important in energy storage, membranes and other biological functions.
Choose Your Level
Lipids
Lipids include:
fats; oils.
They are important because they:
store energy; help form cell membranes; provide insulation; help protect organs.
Recommended for Class 9
Lipids
Definition
Lipids are a group of biological molecules that include fats and oils and are important in energy storage, membranes and other biological functions.
Formula / Key Relation
Many common fats and oils contain glycerol combined with fatty acids.
A simplified triglyceride consists of:
`glycerol + 3 fatty acids`
Lipids provide more energy per gram than carbohydrates in general nutritional terms.
Simplified triglyceride formation:
`glycerol + 3 fatty acids → triglyceride + water`
Lipids — Advanced
Many biological lipids contain long hydrocarbon-rich regions, making them relatively non-polar and poorly soluble in water.
Phospholipids are especially important in cell membranes because they contain both water-interacting and water-avoiding regions.
Common Mistakes
Common Mistakes
- Mistake
Do not say all lipids are fats.
- Mistake
Fats are one type of lipid; the lipid category is broader.
- Mistake
### Sticky Notes
- Mistake
LIPIDS
- Mistake
Examples:
- Mistake
Fats
- Mistake
Oils
- Mistake
Functions:
- Mistake
Energy storage
- Mistake
Membranes
- Mistake
Insulation
- Mistake
Protection
Revision Zone
60-Second Revision
Quick cues from this topic — use them for last-minute revision.
Lipids include fats and oils and play major roles in energy storage, membranes and insulation.
Lipids are biological molecules that include fats and oils. They are important long-term energy stores and also contribute to cell membranes, insulation and protection. Many common fats and oils contain glycerol joined to fatty acids. Lipids generally contain large non-polar regions, so many do not mix well with water. Phospholipids are particularly important because they form a major part of cell membranes.
- Definition
- Lipids are biological molecules that include fats and oils. They are important long-term energy stores and also contribute to cell membranes, insulation and protection. Many common fats and oils contain glycerol joined to fatty acids. Lipids generally contain large non-polar regions, so many do not mix well with water. Phospholipids are particularly important because they form a major part of cell membranes.
Did you understand this topic?
Your answer is saved with your learning record. It does not mark the topic as mastered.
Ready to test yourself?
You've completed the learning section.
Practice
PQ
Q1. What are lipids?
PQ
Q2. Give two functions
PQ
Q3. What are triglycerides made from?
PQ
Q4. Why do many lipids mix poorly with water?
PQ
Q5. What lipid is important in membranes?
Exam Practice
EQ
Q1. Define lipids
EQ
Q2. State four functions of lipids
EQ
Q3. Explain triglyceride composition
EQ
Q4. Explain why many lipids are insoluble in water
EQ
Q5. Explain the role of phospholipids
School-standard facts for Matric and Intermediate. Original explanations — not copied from textbooks.