Lipids

Question 1

What is a saturated fatty acid ?
(Draw one / label it )

Answer 1

• Lipids such as those found in animal fats – saturated lipids don’t contain any carbon-carbon double bonds.

Question 2

What is an unsaturated fatty acid ?

Answer 2

• Lipids which can be found in plants – unsaturated lipids contain carbon-carbon double bonds and melt at lower temperatures than saturated fats.

Question 3

Describe how a triglyceride is formed ?

Answer 3

• Triglycerides are lipids made of one molecule of glycerol and three fatty acids joined by ester bonds formed in 3 condensation reactions, forming 3 water molecules.This process of triglyceride formation is called estrifcation.

Question 4

FEBTTI

What are some functions of triglycerides ?

Answer 4

• Transport triglycerides through the body as fat droplets through the lipoprotein
• Fat storage cells ( adipocytes)
• Thermal insulation reduces heat loss ( heart, kidney)
• Buoyancy for aquatic animals like whales
• Electric insulation- myelin sheath

Question 5

What is a phospholipid ?

Answer 5

• Phospholipids, on the other hand, are a major component of cell membranes. They have a hydrophobic (water-repelling) tail made up of two fatty acids, and a hydrophilic (water-attracting) head composed of a phosphate group and another polar group. When phospholipids are arranged in a bilayer, their hydrophobic tails face inward, while their hydrophilic heads face outward, creating a barrier between the inside and outside of the cell.

Question 6

Draw a fatty acid

Answer 6

did you do it correct ?
DONT LIE

Question 7

What is the function of cholestrol ?

Answer 7

• Just like phospholipid molecules, cholesterol molecules havehydrophobic and hydrophilic regions
  
  • Their chemical structure allows them to exist in the bilayer of the membrane
• Molecules of cholesterol are synthesised in the liver and transported via the blood
• Cholesterol affects the fluidity and permeabilityof the cell membrane
  
  • Itdisrupts the close-packingof phospholipids, increasing the rigidity of the membrane (makes the membrane less flexible)
  • It acts as abarrier, fitting in the spaces between phospholipids. This prevents water-soluble substances from diffusing across the membrane.

Question 8

What are other functions of cholestrol ?

Answer 8

• Molecules of cholesterol are used toproduce steroid-based hormonessuch as oestrogen, testosterone and progesterone, cortisol
• Formation of bile
• Synthesis of vitamin D