Triglycerides and Phospholipids

These flashcards cover key concepts related to triglycerides and phospholipids, including their structures, functions, and testing methods.

What is the main difference between triglycerides and phospholipids?

Triglycerides have three fatty acid chains, while phospholipids have two fatty acid chains and a phosphate group.

What molecule do both triglycerides and phospholipids contain?

A glycerol molecule.

How is a triglyceride formed?

Through three separate condensation reactions between glycerol and three fatty acids.

What is produced during the condensation reactions of triglycerides?

Three water molecules and three ester bonds.

What do we mean by saturated fatty acids?

Fatty acids that have only single bonds between all carbon atoms.

What do we mean by unsaturated fatty acids?

Fatty acids that have at least one double bond between carbon atoms.

What is a significant property of triglycerides that allows them to store energy?

They have a high ratio of carbon to hydrogen bonds.

Why are triglycerides a source of metabolic water?

When triglycerides are oxidized, they can form water molecules.

What are triglycerides known for in terms of their solubility?

They are hydrophobic and insoluble in water.

What is the advantage of triglycerides being hydrophobic?

They can be stored as energy without affecting the water potential of cells.

Compared to muscle tissues, how do lipids such as triglycerides compare in mass?

They are relatively low in mass compared to muscle tissues.

What is the emulsion test used for?

To test for the presence of lipids.

What are the steps in performing the emulsion test?

Dissolve the sample in ethanol, then add distilled water and shake.

What indicates a positive result in the emulsion test?

A white emulsion forms.

What does the term 'emulsion' refer to in the context of the emulsion test?

A mixture where lipids are dispersed in water as tiny droplets.

What characterizes the structure of phospholipids?

They consist of a glycerol backbone, two fatty acids, and a phosphate group.

What makes the head of phospholipids hydrophilic?

The negative charge on the phosphate group.

What property do the fatty acid tails of phospholipids have?

They are hydrophobic and repel water.

What structure do phospholipids form in aqueous environments?

A bilayer structure.

Why do phospholipids form a bilayer in membranes?

The hydrophilic heads face outward toward water, while the hydrophobic tails face inward, away from water.

What is the significance of the phospholipid bilayer in cells?

It forms the basic structure of cell membranes.

How are phospholipids described in terms of charge?

They are polar due to the two different charged regions.

What is the function of the phosphate group in phospholipids?

It gives the molecule a hydrophilic characteristic.

How does a saturated fatty acid differ from an unsaturated fatty acid in terms of hydrogen?

Saturated fatty acids have maximum hydrogen bonds, while unsaturated fatty acids have fewer due to double bonds.

What does 'R group' signify in relation to fatty acids?

It indicates that the number of carbons and hydrogens can vary.

How do triglycerides impact the water potential of cells?

Their hydrophobic nature means they do not affect water potential, preventing overhydration of cells.

What role does the glycerol portion play in triglycerides?

It provides a backbone for attaching fatty acids.

How many ester bonds are formed when one triglyceride is synthesized?

Three ester bonds are formed.

Why is it advantageous for animals to store triglycerides?

They provide a dense form of energy storage without adding significant weight.

What would happen to triglycerides in the body when oxidized?

They produce energy and metabolic water.

What are the implications of triglycerides being hydrophobic on lipid storage?

They can be stored in large amounts without affecting osmosis.

How do the properties of phospholipids differ from triglycerides?

Phospholipids have a hydrophilic head and hydrophobic tails, while triglycerides lack the phosphate group.

What type of bond is formed between fatty acids and glycerol in triglycerides?

Ester bonds.

What is the outcome if triglycerides are broken down?

They release energy and metabolic water.

Describe the difference in physical properties between triglycerides and phospholipids.

Triglycerides are typically solid or liquid fats, while phospholipids form bilayers in water.

What happens to a cell when it has too much water due to unregulated triglyceride storage?

The cell could burst due to excess water intake.

Why are camels able to survive in arid conditions?

They store triglycerides in their humps, which provide metabolic water upon breakdown.

What is a key factor leading to the energy-storing capacity of triglycerides?

The high amount of carbon-hydrogen bonds.

Define the term 'condensation reaction' in the context of lipids.

A reaction where water is removed to bond glycerol with fatty acids.

What is the pair of types of bonds called that links fatty acids to glycerol?

Ester bonds.

What negatively charged part of the phospholipid is responsible for its hydrophilicity?

The phosphate group.

Why are phospholipids crucial for cell membranes?

They form a bilayer that regulates what enters and leaves the cell.

What is the primary structure observed in the cell surface membrane composed of phospholipids?

Phospholipid bilayer.