Lipids / Triglycerides And Phospholipids Flashcards
(16 cards)
What are lipids?
Lipids are biological molecules made of carbon, hydrogen, and oxygen, soluble only in organic solvents such as alcohols.
What are the main types of lipids?
The main lipid types are triglycerides and phospholipids.
What are triglycerides composed of?
Triglycerides are made of one molecule of glycerol and three fatty acids joined by ester bonds formed in condensation reactions.
What determines the type of fatty acids in triglycerides?
There are over 70 different types of fatty acids that vary in chain length, presence, and number of double bonds.
What are saturated fatty acids?
Saturated fatty acids do not contain any carbon-carbon double bonds.
What are unsaturated fatty acids?
Unsaturated fatty acids contain carbon-carbon double bonds, allowing the molecule to bend.
What is the significance of triglycerides in energy storage?
Triglycerides have a high ratio of energy-storing carbon-hydrogen bonds, making them excellent energy stores.
What is the mass to energy ratio of triglycerides?
Triglycerides have a low mass to energy ratio, making them good storage molecules.
How do lipids affect water potential in cells?
Being large and non-polar, lipids are insoluble in water, so their storage does not affect the water potential of cells.
What is the emulsion test?
An emulsion test is used to test for the presence of lipids by adding water and ethanol to a sample and observing for a cloudy-white color.
What is the structure of phospholipids?
In phospholipids, one fatty acid of a triglyceride is substituted by a phosphate-containing group, resulting in a hydrophilic head and hydrophobic tails.
What is the significance of the polar nature of phospholipids?
The polar nature allows phospholipids to form bilayers in aqueous environments, crucial for cell membrane structure.
What role do phospholipids play in cell recognition?
Phospholipids can form glycolipids with carbohydrates, which are important for cell recognition on the cell surface membrane.
What is the emulsion test used for?
To test for the presence of lipids in a sample.
What is the emulsion test procedure?
Mix the sample with ethanol, then add water.Shake to mix.A milky white emulsion will form if lipids are present.
Why does a milky white emulsion form in the emulsion test?
Lipids are insoluble in water and form a cloudy emulsion when added to it.
