Lipids, biological molecules

Alternative transcript:

double bond. -Trans fatty acids have the H atoms on different sides of the double bond. @ppppph METHYL GROUP CH₂ POLYUNSATURATED (>1 DOUBLE BONDI HYDROCARBON CHAIN (e.g. UNOLEIC ACIDI CARBOXYL GROUP COOH Phospholipids Formed from two fatty acids, a glycerol and a phosphate. As the phosphate is polar, it is soluble in water. The fatty acid tails are non-polar and therefore insoluble in water. Phospholipids are amphipathic (They have hydrophobic and hydrophilic parts. As a result of this, they form monolayers or bilayers when in water). O=P-O ESTER ITT BONDS GLYCEROL НО PHOSPHATE IP HYDROPHRIC POLAR HEAD Cholesterol Amphipathic like phospholipids so have hydrophilic and hydrophobic regions. Cholesterol molecules are synthesised in the liver and transported in the blood. GLYCEROL Cholesterol affects the permeability of cell membranes. It disrupts the close packing of phospholipids making the cell membrane more flexible. This prevents water soluble molecules from diffusing across the cell membrane. Cholesterol molecules are used to produce steroid based hormones such as oestrogen, testosterone, progesterone. CH₂ GLYCEROL HYDROPHILIC REGION (POLARI HYDROPHOBIC FATTY ACID TAILS NON-POLARI + FATTY ACID FATTY ACID CH₂ CH₂ CH₂ FATTY ACID CH₂ The ester bond Triglycerides are formed by esterification. Making an ester bonds forms from the hydroxyl group in glycerol bonding with the carboxyl group of the fatty acid. The H from glycerol combines with the OH from a fatty acid which makes water. This is why esterification is a condensation reaction. Therefore in triglycerides, three water molecules are made. AN ESTER BOND CH CH₂ CH CH₂ HYDROPHOBIC REGION (NON-POLARI CONDENSATION 3H₂0 GLYCEROL FATTY ACID FATTY ACID FATTY ACID TRIGLYCERIDE