BIOL 1001 Lecture 24: BIOL 1001 5.3 - Lipids are a diverse group of hydrophobic molecules

• School: Memorial University
• Department: Biology
• Course: BIOL 1001
• Professor: Margaret Caldwell

Document Summary

Lipids are a diverse group of hydrophobic molecules. Generally not big enough to be considered macromolecules. Lipids: are grouped together because they share one important trait: they mix poorly, if at all, with water: hydrophobic behaviour is based on their molecular structure. Not polymer but are large molecules assembled from smaller molecules by dehydration reactions. Separate from water because water molecules hydrogen-bond to each other and exclude fats. Hydrocarbon chains are like gas molecules and rich in energy. Gram of fat stores twice as much energy as that of a polysaccharide. Animals are mobile so they store their energy fat. Humans and other mammals store their long-term food reserves in adipose cells which swell and shrink as fat is deposited and withdrawn from storage: adipose tissue also cushions organs like kidneys. Layer of fat beneath the skin insulates your body. Hydrogenated vegetable oils: unsaturated fats have been synthetically converted to saturated fats by adding hydrogen, peanut butter, margarine.