1. Unit D: Humans Systems

2. Essential nutrients
Carbohydrates
Lipids
Proteins
Nucleic acids

3. “Chemicals of Life”
macromolecules

4. The essential nutrients are considered macromolecules because they are large and complex
Many are polymers – long chains of small, repeating chemical subunits

5. Assembling Macromolecules
All macromolecules are assembled in the same basic way
Dehydration synthesis - removing an -OH group from one subunit and a -H atom from another subunit
A molecule of water is removed and a new covalent bond is formed

7. Disassembling Macromolecules
The reverse of dehydration
Hydrolysis - a molecule of water is added
“water splitting”

8. Carbohydrates
Macromolecules that always contain carbon, hydrogen, and oxygen - and almost always in the same proportion (1 : 2 : 1)
Main function - short or long term energy storage
2 main types - simple sugars and polysaccharides

9. Simple Sugars 3 to 7 carbon atoms
Monosaccharides contain a single sugar units
Disaccharides contain 2 units

10. Sucrose (table sugar)

11. Polysaccharides “poly” = many Many linked simple sugars
Ex. starch - repeating units of glucose. Provides energy storage in plants
glycogen - repeating units of glucose. Provides energy storage in animals
Cellulose – composes cell walls

13. Foods can be tested for Simple sugars using Benedicts solution
The solution is blue and will turn color depending on the amount of sugar present
Iodine is used to identify starch (will turn blue-black in the presence of starch)

14. Lipids insoluble in water Contain carbon, hydrogen and oxygen
Main function - energy storage (fats and oils), cell membranes (phospholipids), sex hormones (steroids)
When glycogen stores have been built up, excess carbohydrates are converted into fat

15. Lipid Groups 1. triglycerides Glycerol + 3 fatty acids +
Fatty acids may be short, long, saturated, or unsaturated

16. Saturated vs. Unsaturated
Saturated - only single bonds, maximum number of hydrogen atoms
Solid at room temperature (FAT)
Unsaturated - contains some double bonds
Liquid at room temperature (OILS)

17. Polyunsaturated fats Many double bonds Easily broken down
‘Healthy’ type of fat

18. 2. Waxes
Long chains of fatty acids attached to long chains of alcohols or carbon rings
Waterproof
Phospholipids
Have a phosphate molecule attached
Found in cell membranes

19. Foods can be tested for Lipids using Sudan IV indicator
Substance will change from dark red to a reddish orange color
Brown bag test
Substance is put on a brown bag and liquid is left to evaporate. If the bag is translucent – positive test

20. Proteins Made from amino acids
Composed of carbon, hydrogen, oxygen, nitrogen
Main function - structure, enzymes, repair and immunity
Structurally complex and diverse

21. Amino acids R-group determines identity of the aa. 20 different types
Our body can synthesize 11 - the rest must come from our diet: “essential amino acids”

22. Peptide bond
Amino acids are joined by a peptide bond (dehydration synthesis!)

23. Chains of aa’s are twisted and coiled into complex 3-dimensional structures
The R-group determines solubility (hemoglobin vs. fingernails)

24. Chemistry of Proteins Denaturation
Temporary change in shape of protein because of exposure to extreme heat , radiation or change in pH
Coagulation
Permanent change in shape of protein
If you body does not get any food…….
Proteins break down for energy when carbs and lipids have been depleted

25. Foods can be tested for Proteins by using Biuret’s solution
Add the blue solution to your sample; if it turns pink/purple protein is present

26. Nucleic Acids Largest and most common molecule in living things
Building blocks of genetic code
Long chains of subunits called nucleotides
Main function - transfer and expression of genetic information
Two types: DNA and RNA

27. Vitamins and Minerals Not classified as macromolecules
Essential to structure and function of cells but only required in small amounts
Vitamins - organic compounds involved in disease resistance, tissue growth, etc.
Minerals - inorganic compounds involved in building of bones and cartilage and an essential component of enzymes and hormones, and vitamins

28. Water- Essential but not a nutrient
Absorbs/releases energy (moderate temp)
Medium in which reactions take place
Excellent solvent
60% of cells’ mass
Cushions body organs
Lubricates
Cleaning(tears/saliva)