3.5 lipids

Question 1

What elements do are lipids made out of, and what proportion of element is less then carbohydrates ?

Answer 1

1) Hydrogen oxygen carbon

2) less proportion of OXYGEN

Question 2

Are lipids polar? Why?

Can they dissolve in water?

Answer 2

Lipids are not polar because electrongativity differences are too small and electrons are balanced overall.

This means they can not dissolve in water

Question 3

Are lipids polymers like polysaccharides? Why?

Answer 3

Lipids are not polymers but rather macromolecules, as they ARE NOT MADE FROM REPEATING UNITS OF MONOMER

Question 4

What do triglycerides consist of , and how bonded?

How broken down

Answer 4

One glycerol and three fatty acids , bonded in condensation reactions to form ester binds (COOC), so OH from glycerol and COOH from carboxylic acid combine .

3) broken down by hydrolysis, THREE WATERS supplied and enzyme breaks down

Question 5

Difference between plant and animal fats?

Answer 5

= animal fats are solid at room temperature , but will melt if warm up (BUTTER)
= plant fats are liquid and called OILS

Question 6

What is the difference between stairwted and unsaturated fatty acids ?

What name given to those with multiple fatty acid double bonds?

Answer 6

Saturated only have carbon Carbon single bonds , whereas unsaturated will have atleast one carbon carbon double bond along the way. One double = mini saturated, more = poly saturated

Question 7

What properties are given asa result if saturated vs unsaturated fatty acids?

Answer 7

PRESENCE OF CARBON CARBON DOUBLE BONDS WILL CAUSE A KINK IN THE MOLECULE AND MAKE IT BEND .
- thus they cannot pack so closely together , making unsaturated LIQUID AT ROOM TEMPERATURE Rather than solid = thus oils.

• plants contain these unsaturated fatty acids, and thus oils.
  2) solids don’t king so they can pack closely forming solids

Question 8

What are phospholipdis

How is a phospholipid structured and what makes them good for cell membranes

Answer 8

= modified triglycerides, here they LOSE ONE FATTY ACID CHAIN and replace by a PO4-3 PHOSPHATE GROUP

• the charged group (not polar) orientates itself in a way so it goes around allowing it to interact with water , so HYDDROPHILLIC whisker fatty acids non polar and remain HYDROPHOBIC, interact with other fats
  3) used for cell membranes so they can interact with both aqueous interior and exterior,

Question 9

What is a surfactants

Answer 9

Basally a phospholipids, the way they stick their tails out in the air when contact with water , they are surface active agent (doing something in contact with a surface )

Question 10

Sterols , how are they similar to phospholipids

Answer 10

Not fat or lipids, but share a hydrophobic region of four carbon rings and a hydrophilic section with a charged OH group at one end , which is POLAR (not ion)

Question 11

Cholesterol
Where are they found snd how orientsted ?
What is their role?

Answer 11

• manufactured in liver and intestines
• role in membranes, positioned with OH groups with PO4- heads , interacting with it, whilst carbon rings are hydrophobic like the fatty acids , which bind to them (MAINLY BINDS TO TAIL, INTERACTS WITH HEAD!!!
• role is to REGULATE FLUIDITY, makes them fluid at low temperatures (does not allow phospholipids to come too close and crystallise and solids) and not that liquid in high temperatures .
• cause them to pack closely together, making more rigid and less fluid, but regulates

Question 12

Why do these lipids being insoluble matter?

Answer 12

Don’t allow water to go in cell and swell, all lipids (so triglyceride, phospholipid, cholesterol ) are insoluble

Reibereien w lipid is Corbin hdyrone oxygen, less oxygen…

Question 13

What three molecules are made by cholesterol?

Answer 13

• vitamin d , steroid hormones , and bile

Question 14

What are key roles of lipids? (7 roles)

Answer 14

• membrane and vesicles
• hormone production (steroid ones)
• insulation : electrical insulation for nerve transmission, thermal for animals like penguin
• waterproofing , bird feathers and plant leaf waxy cuticle (stops evaporation)
• making water
• storage of energy
• cushioning of vital organs
  Buoyancy like whales

Question 15

Advantages of lipids as an energy store?

Disadvantage?

Answer 15

• insoluble so won’t affect water potential of cell components and mess gradients up
• can be stored in compact way in the sense that it doesn’t need as MUCH FATS AS CARBOHYDRATES TO STORE SAME AMOUNT OF ENERGY, a lipid will store twice as much energy as fat
• also unsaturated means more can be stored in animals
• hydrolysis of it gives glycerol and fatty acids thst can be used in respiration alike

2) Harder to extract as energy is put in, meaning only good for emergencies.