Carbohydrates & lipids - lipids Flashcards
What are examples of lipids in living organisms?
Fats, Oils, Waxes, Steroids
What atoms do lipid macromolecules contain?
Carbon, Hydrogen, Oxygen
How does the structure of lipids affect their solubility?
The non-polar nature makes lipids insoluble in water or other polar solvents.
What improves lipid solubility in living organisms?
Combining lipid molecules with other molecules, e.g. Glycolipids, Lipoproteins
How are triglycerides formed?
Three fatty acids join to one glycerol molecule.
What types of carbon bonds can fatty acids contain?
Saturated (only single bonds) and Unsaturated (one or more double bonds)
What is the process called that forms triglycerides?
Esterification
What forms an ester bond in triglycerides?
The hydroxyl (-OH) group of glycerol bonds with the carboxyl group (-COOH) of a fatty acid.
What type of reaction occurs when an ester bond is formed?
Condensation reaction
How many water molecules are released when one triglyceride forms?
Three water molecules
What distinguishes phospholipids from triglycerides?
Phospholipids contain two fatty acids bonded to glycerol, with the third replaced by a phosphate ion.
What is the nature of the phosphate ion in phospholipids?
Polar and hydrophilic
What are the fatty acid tails in phospholipids characterized as?
Non-polar and hydrophobic
What does amphipathic mean in relation to phospholipids?
Having both hydrophobic and hydrophilic regions
What types of structures can phospholipid molecules form in water?
Monolayers or bilayers
What do triglycerides release upon hydrolysis?
Glycerol and fatty acids
Why are lipids considered energy-dense?
They contain 2× more energy per gram than most carbohydrates.
What is metabolic water?
Water produced when lipids are respired, useful as a dietary water source.
Where are lipids stored in animals?
Adipose tissue
What are the two types of fat storage in animals?
Subcutaneous fats and Visceral fats
What is the function of adipose cells?
To contain large globules of fat
What is blubber?
Thick adipose tissue in endotherms that helps trap heat.
What is an example of a plant that stores fats for energy?
Olives, sunflowers, nuts, coconuts, oilseed rape
