(a) Find the value of \(\gamma\) for the following situation. An astronaut measures the length of his spaceship to be 100 m, while an earthbound observer measures it to be 25.0 m. (b) What is the speed of the spaceship relative to Earth?
Unit 3 - Macromolecules: Lipids & NucleicAcids Macromolecules: Lipids • Lipids - large molecules (not truly polymers) that don’t mix well with water. • Most heterogenous class of molecules. • Major component of cell membranes. • 3 major classes of lipids: fats, phospholipids, steroids Lipids: Fats • Fat - made from glycerol and fatty acids. Hydrophobic due to the non polar C and H bonds in the hydrocarbon chain, water molecules don’t bond with fat. • Glycerol: an alcohol with 3 carbons with a hydroxyl group each. • Fatty acids: made of a long carbon skeleton with a carboxyl group at one end with the rest being a hydrocarbon chain. • To make a fat, 3 fatty acid molecules (can be same or different) are joined to glycerol through ester linkage, creating triacylglycerol, which is non polar. • Functions: • Energy storage. • 1 gram of fat is twice as much energy as 1 gram of a polysaccharide like starch. Saturated v.s unsaturated fat • Saturated or unsaturated refers to the fatty acid’s hydrocarbon chain structure. • Saturated fat - saturated with hydrogen, no double bonds between carbon atoms to allow maximum flexibility of the molecule. • Most animal fats are saturated (e.g lard, butter) • The lack of double bonds allow the molecules to pack together. • Usually solid at room temperature. • Unsaturated fat - has double bonds with less hydrogen, often creating a “bend” or kink in the hydrocarbon chain. • Fats of plants, fish. • Referred to as oils (e.g olive oil