1. Biomolecules: carbohydrates and lipids

2. H O C N Few elements but many compounds
In the complex world of living organisms, there
are essentially 4 constituent elements:
hydrogen
oxygen
carbon
nitrogen H O C N
Biomolecules: carbohydrates and lipids

3. Biological macromolecules
Biological macromolecules can be divided into 4 families
CARBOHYDRATES (or saccharides or sugars)
LIPIDS (or fats)
PROTEINS
NUCLEIC ACIDS
Biomolecules: carbohydrates and lipids / Biological macromolecules

4. Mean composition of an organism
The ‘dry’ part of living organisms consists of of proteins and nucleic acids.
Carbohydrates and lipids are used as a source of energy.
Biomolecules: carbohydrates and lipids / Mean composition of an organism.

5. The cell
Cell is an autonomous structure but it is in relationship with other cells and the outside world.
Biomolecules: carbohydrates and lipids / The cell

6. Metabolism: the role of energy

7. Biochemical reactions involved in metabolism
The metabolism
The set of reactions that take place in cells and in the organism are known as “metabolism” (from the Greek metabolé meaning “change, modification”).
Biochemical reactions involved in metabolism
energetic status
physiological role
Biomolecules: carbohydrates and lipids / Metabolism: the role of energy

8. Endoergonic (require energy) Exoergonic (release energy)
Metabolic maps
Very complex sequences of biochemical reactions are described by metabolic maps.
Reagents
Products
Direction of reactions (Energetic status)
Precursors
Metabolites
Endoergonic (require energy) or
Exoergonic (release energy)
Biomolecules: carbohydrates and lipids / Metabolism: the role of energy

9. Reactions of metabolism
Catabolism vs Anabolism
Reactions of metabolism
catabolism
anabolism
degrade the larger molecules with oxidation and
are exoergonic
construct large molecules us ing reduction and
are endoergonic
Biomolecules: carbohydrates and lipids / Matabolism: the role of energy

10. Carbohydrates: energy and support
Carbohydrates, also known as saccharides or sugars, are composed of carbon, oxygen and hydrogen.
Molecules to get energy from by breaking the chemical bonds with complex sets of reactions.
The result is a stable system.
They form the scaffolding support of plants.
Biomolecules: carbohydrates and lipids / Carbohydrates: energy and support

11. Carbohydrates Carbohydrates can be divided into 3 broad groups:
Monosaccharides
Disaccharides
Polysaccharides
Biomolecules: carbohydrates and lipids / Catabolism vs Anabolism

12. Monosaccharides
Contain 4, 5 or 6 carbon atoms but the most common in nature are pentoses or hexoses
Depending upon they contain the aldehyde or the ketone functional group the monosaccharides are divided into:
ketoses
aldoses
Biomolecules: carbohydrates and lipids / Monosaccharides

13. The Dextro configuration
Monosaccharides consist of D or L configurations by how the hydroxyl group linked to carbon is arranged.
Biomolecules: carbohydrates and lipids / The Dextro configuration

14. The cyclical structure
Monosaccharides may also occur with a closed structure: cyclical. An example is glucose.
Biomolecules: carbohydrates and lipids / The cyclical structure

15. The energy of life
Sources of energy for all living things are Glucose and Fructose (ketohexose) found in fruit and honey together with ribose and deoxyribose, which are constituents of nucleic acids.
Biomolecules: carbohydrates and lipids / The energy of life

16. Carbohydrates derived from the condensation
Oligosaccharides and Disaccharides
Carbohydrates derived from the condensation
of several monosaccharide molecules (from two to five), with loss of one or more molecules of water and the formation of a glycosidic bond.
Disaccharides are formed by the union of 2 monosaccharides
Biomolecules: carbohydrates and lipids / Oligosaccharides and Disaccharides

17. We classify polysaccharides into:
Consist of long chains whose repeating units are of the individual monosaccharides.
We classify polysaccharides into:
RESERVE
SUPPORT
Example: Starch
Example: Cellulose
Biomolecules: carbohydrates and lipids > Polysaccharides

18. benzene, chloroform, and ethers.
Lipids: hydrophobic chains
Lipids, or fats, are organic compounds characterized by their hydrophobicity, or insolubility
in polar liquids such as water, and lipophilicity, or solubility in apolar solvents such as
benzene, chloroform, and ethers.
Fats are macromolecules essential for living organisms
Represent an energy reserve
Are at the base of the structure of the cell membrane
Biomolecules: carbohydrates and lipids > Lipids: hydrophobic chains

19. Groups of Lipids TRIGLYCERIDES WAXES STEROIDS PHOSPHOLIPIDS
Biomolecules: carbohydrates and lipids > Groups of Lipids

20. 1. Triglycerides
Triglycerides are derived by the esterification of 1 molecule of glycerol with 3 fatty acid molecules.
Biomolecules: carbohydrates and lipids > Triglycerides

21. 1. Triglycerides: fats and oils
Triglycerides in which saturated acids dominate, such as butter, appear as solids and are called fats.
Triglycerides in which there is a strong presence of unsaturated acids are liquids and are called oils, abundant in fish.
Biomolecules: carbohydrates and lipids > Triglycerides: fats and oils

22. 2. Waxes
Waxes are a rather heterogeneous mixture of compounds of alcohols, ketones, alkanes and especially of the esters of a fatty acid (palmitic acid, stearic acid etc.) together with an alcohol (cetyl, ceryl etc.), all of which have very long chains.
Waxes are extremely insoluble in water
and chemically inert.
Waxes also provide an effective barrier against bacteria
Biomolecules: carbohydrates and lipids > Waxes

23. 3. Steroids
Steroids are united by a base structure formed by 3 hexatomic rings and a pentatomic ring called sterane, which are linked to an aliphatic chain and an –OH group.
The best known of the steroids is cholesterol.
Biomolecules: carbohydrates and lipids > Steroids

24. Phospholipids
Phospholipids (or glycerophospholipids) are derived from the esterification of glycerol, like the triglycerides, but, unlike the latter, have two fatty acid molecules and a molecule of phosphoric acid, to which, in general, a choline group is linked.
Biomolecules: carbohydrates and lipids > Phospholipids

25. Amphipathic nature
The phosphate group is the hydrophilic ‘head’ of the molecule while the two lipid chains are the hydrophobic ‘tail’.
The double nature of the phospholipid molecules are termed amphipathic.
Biomolecules: carbohydrates and lipids > Amphipathic nature

26. Bilayers structure: the cell membrane
In liquid, phospholipids line up spontaneously next to each other, aligning the lipid chains and turning the hydrophilic heads towards the water.
The cell membrane, appropriately called a “phospholipid bilayer”, is an example of bilayers structure in line with the model proposed by Singer and Nicolson in 1972 that has been further improved with the so-called “fluid mosaic” model.
Biomolecules: carbohydrates and lipids > Amphipathic nature