Table of Contents
Are lipids more or less dense than water?
Since lipids have a lower density than water (oil floats on the surface), the density of lipoproteins depends on the ratio of lipid to protein.
Why are some lipids solid and others liquid?
To form a solid, molecules need to pack together nicely, while in a liquid there is less order and the molecules flow around each other. Fat molecules are mostly made up of long, straight hydrocarbon chains. By definition, fatty molecules that form liquids are called oils and those that form solids are called fats.
Are lipids hydrophobic?
Molecules such as proteins, nucleic acids, and carbohydrates have an affinity for water and are called hydrophilic (“water-loving”). Lipids, however, are hydrophobic (“water-fearing”).
How does water interact with lipids?
Most lipids are non-polar (having no charged areas) or only slightly polar, with a very few charged areas. Water mixes with hydrophilic (water-loving) compounds by sticking to their charged groups. Since lipids lack charged groups, the water molecules have nothing to stick to and don’t mix with them.
Why some lipids do appear liquid at room temperature and some are semi solids or solids?
Unsaturated fats have one or more double bonds inside their fatty acid chains. The two carbons on the hydrocarbon molecules each have triple or double bonds, and hydrogens cannot saturate them. This makes the entire molecular structure weaker, so the substance stays liquid at room temperature.
How do lipids differ in their degree of saturation or unsaturation?
Lipids differ in their degree of saturation or unsaturation according to their number of double bonds. The degree of saturation determines the hardness of a fat at a given temperature.
What happens if a liquid is more dense than water?
Students will also be able to explain that if a liquid is more dense than water, it will sink when added to water, and if it is less dense than water, it will float. A liquid, just like a solid, has its own characteristic density.
What is the concept of density of liquid?
Key Concepts 1 A liquid, just like a solid, has its own characteristic density. 2 The density of a liquid is a measure of how heavy it is for the amount measured. 3 If a liquid that is less dense than water is gently added to the surface of the water, it will float on the water.
Why is vegetable oil less dense than water?
The vegetable oil is less dense than water because it weighs less than an equal volume of water. Predict what will happen when you pour the vegetable oil into the water. Will the oil sink or float? The oil will float on the water. Pour the vegetable oil onto the water to see if it sinks or floats. The oil floats in a separate layer on the water. 3.
What is the difference between lipids and carbohydrates?
Lipids are not defined by the presence of specific functional groups, as carbohydrates are, but by a physical property—solubility. Compounds isolated from body tissues are classified as lipids if they are more soluble in organic solvents, such as dichloromethane, than in water.