Triglycerides, Phospholipids & Steroids Flashcards
What are triglycerides?
Lipids (fats)
Are lipids soluble in water or insoluble?
Insoluble
What are lipids soluble in?
Organic solvents such as ethanol
What is the structure of triglycerides?
Glycerol backbone with 3 fatty acid chains
What is the link between a glycerol molecule and a fatty acid called?
An ester bond
How do triglycerides form?
Through esterification (a condensation reaction where a molecule of water is formed each time an ester bond is made)
What is the role of lipids?
- Energy source
- Heart insulation
- Can be broken down to release energy
- Protection around delicate organs
Why is it good that lipids are insoluble?
Because they can be stored in high concentrations in cells where they appear as small droplets in the cytoplasm and don’t affect water potential
What is water potential?
The ability of water to move across a membrane
What is the structure of phospholipids?
Glycerol backbone with a phosphate group on top and two fatty acid chains (similar to triglycerides)
On a phospholipid, is the head hydrophobic or hydrophilic?
The head is hydrophilic and the tails are hydrophobic
What are phospholipids important for?
The formation of cell membranes
What is a molecule called that has both hydrophilic and hydrophobic sections?
amphipathic
Due to a phospholipid having a hydrophilic head and hydrophobic tail, they form bilayers in aqueous environments
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Many hormones are steroids. Give an example
Testosterone and Oestrogen
