0. By: Julianne, Madeline, Jade & Joy
Lipids
Triglyceride
By: Julianne, Madeline, Jade & Joy

1. Structure of a Lipid
- Lipids are made of fatty acids including CHO -The more C-C bonds a molecule has, the more energy it can store -Hydrophilic head and hydrophobic tail -A triglyceride is made of glycerol and fatty acids

2. Structure of Glycerol

3. Structure of Fatty Acid:
=Hydrophobic tail- hates water

4. Saturated and Unsaturated Fatty acids:
All “C”s have “H” attached
*Not all “C”s have an H attached.
*There is: double bond between 2 carbons

5. Butter is a saturated fat because the tails of saturated fat can be close together to form a solid.
Oil is not saturated because the tails “bump” together to form a liquid.
If the fatty acid part of a lipid is saturated, then it is a saturated fat.

6. Isomer:
-molecules with the same molecular formula, but different arrangements of atoms. -physical and chemical -properties may be very different.
e.g. Isomer of C4H10O:

7. Structural isomerism :
Positional: Due to a change in the arrangement of the atoms in a structure
Functional: the atoms are arranged In such a way that there is a change in the functional group.
Stereoisomerism (Due to the spatial properties of the molecule itself):
Geometrical: restricted rotation (often involving a carbon-carbon double bond)

8. Trans Isomer: 2 atoms that are locked on opposite sides of the double bond
Cis Isomer: 2 atoms that are locked on the same side of the double bond.

9. Fatty Acid in Cell Membrane
-The cell membrane is bilayer made out of phospholipids, cholesterol, and proteins.
-Two fatty acids + a phosphate head= phospholipid
-Fatty acids are hydrophobic (water-insoluble), the phosphate head is hydrophilic

10. Fatty acids orient inward, creating hydrophobic space in the center of the bilayer.

11. Membrane Fluidity
-Decided by lipid composition and temperature -Transition temperature: where gel becomes crystalline -shorter or unsaturated fatty acids → lower trans. Temp.

12. Cholesterol
-Doesn’t change membrane’s transition temperature, but broadens the transition range by reducing phospholipid movement -Stiffens the membrane both below and above trans temp

13. MEMBRANE models
Davson-Danielli -continuous bilayer -polar head + protein ‘s beta sheet -ionic electrostrostatic bonds
Singer-Nicolson
-a.k.a the lipid globular protein mosaic model
-discontinuous lipid bilayer
-glob of proteins
-the membrane’s hydrophobic core is made up of nonpolar fatty acids and hydrophobic proteins
-ionic electrostatic bonds aren’t the energy source

14. Three Functions of Lipids
a) Energy Storage -Long-term energy storage -Energy stored in C-C bonds -Fatty acid tails have a lot of C-C bonds b) Cell Membrane -Made up of phospholipids -Glycerol, diglyceride, phosphate group -Head is hydrophilic, tail is hydrophobic c)Cholesterol -Lipids are the precursor for cholesterol -Functions of cholesterol: Production of hormones Stabilizes phospholipid bilayer Aids in digestion d)Other functions include: Protection & Insulation

15. Importance of Lipid Synthesis for Cellular reproduction
-When cells reproduce, membrane divides, cell gets smaller -Membrane is made up of lipids -Lipid synthesis needed to maintain original cell size

16. Fatty acid tail O H H H H H H C C C C C C H H O H H H H H H C O H C O
Glycerol O H H H H H H C C C C C C H H O H H H H H H C O H C O
Head is hydrophilic
Tail is hydrophobic
Carboxyl group on end H C O H

17. CONDENSATION H H C O H H C O H H C O H O C H H H
Lipids form through condensation (Dehydration synthesis)
Anabolism

18. O H H H H H H C C C C C C H H O H H C O H H H H H O H H H H H H C C C C C C C H H O H O H H H H H H C O H H H H H H C C C C C C H H O H O H H H H H

19. H O H H H H H H C O H C C C C C C H O H H H H H H H C O H O H H H H H
Hydrolysis
Water is added back in
The tails come off
Energy is stored in C-C bonds O H H H H H H