Table of contents

1. Introduction to Anatomy & Physiology5h 43m
2. Cell Chemistry & Cell Components12h 36m
3. Energy & Cell Processes10h 6m
4. Tissues & Histology10h 3m
5. Integumentary System2h 20m
6. Bones & Skeletal Tissue2h 16m
7. The Skeletal System2h 35m
8. Joints2h 17m
9. Muscle Tissue2h 33m
10. Muscles1h 11m
11. Nervous Tissue and Nervous System1h 35m
12. The Central Nervous System1h 6m
- Introduction to the Central Nervous System
  18m
- The Cerebrum
  48m
13. The Peripheral Nervous System1h 26m
14. The Autonomic Nervous System1h 38m
15. The Special Senses2h 41m
16. The Endocrine System2h 48m
17. The Blood3h 22m
18. The Heart3h 42m
19. The Blood Vessels3h 35m
20. The Lymphatic System3h 16m
21. The Immune System14h 37m
22. The Respiratory System3h 20m
23. The Digestive System2h 5m
24. Metabolism and Nutrition4h 0m
25. The Urinary System2h 39m
26. Fluid and Electrolyte Balance, Acid Base Balance37m
27. The Reproductive System2h 5m
28. Human Development1h 21m
29. Heredity3h 32m

2. Cell Chemistry & Cell Components

Lipids

Anatomy & Physiology

2. Cell Chemistry & Cell Components

Lipids

Previous problemNext problem

Problem 5

Textbook Question

Cooking oil lipids consist of long, unsaturated hydrocarbon chains. Would you expect these molecules to form membranes spontaneously? Why or why not? Describe, on a molecular level, how you would expect these lipids to behave in water.

Verified step by step guidance

Understand the structure of cooking oil lipids: These lipids are typically triglycerides, composed of glycerol and three fatty acid chains, which are often unsaturated.

Recognize the nature of unsaturated hydrocarbon chains: Unsaturated chains have one or more double bonds, causing kinks that prevent tight packing.

Consider the properties of membrane-forming lipids: Membrane lipids, like phospholipids, have a hydrophilic head and hydrophobic tails, allowing them to form bilayers in water.

Analyze the behavior of triglycerides in water: Triglycerides lack a hydrophilic head, making them non-polar and hydrophobic, so they do not form bilayers or membranes.

Predict the interaction of triglycerides with water: In water, triglycerides tend to aggregate into droplets or micelles, minimizing their exposure to water, rather than forming membranes.

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Lipid Structure

Lipids, particularly those found in cooking oils, are primarily composed of long hydrocarbon chains that can be saturated or unsaturated. Unsaturated lipids contain one or more double bonds, which introduce kinks in the chain, preventing tight packing. This structural characteristic influences their physical properties, such as fluidity and melting point, and is crucial for understanding their behavior in biological membranes.

Amphipathic Nature of Lipids

Many lipids are amphipathic, meaning they possess both hydrophilic (water-attracting) and hydrophobic (water-repelling) regions. In an aqueous environment, the hydrophilic heads of lipid molecules tend to interact with water, while the hydrophobic tails avoid it. This property drives the spontaneous formation of structures like bilayers, which are fundamental to cell membrane formation.

Spontaneous Membrane Formation

The spontaneous formation of membranes occurs due to the thermodynamic favorability of minimizing the exposure of hydrophobic regions to water. When lipids are placed in water, they arrange themselves into bilayers, with hydrophobic tails facing inward and hydrophilic heads facing outward. This arrangement stabilizes the structure and is essential for the formation of cellular membranes, allowing for compartmentalization within cells.