1. Biochemistry - Macromolecules
Carbohydrates, Lipids, Proteins and Nucleic Acids
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2. Carbohydrates Body’s most important source of energy
Plants are our source of carbohydrates
Three basics groups of carbohydrates: mono saccharides, disaccharides and polysaccharides
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3. Monosaccharides
Simple sugar molecules made up of chains or rings of carbon, hydrogen and oxygen in the ratio of 1:2:1
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4. Disaccharides
Sugars made up of two mono saccharides formed by dehydration synthesis (or condensation reaction) (sucrose is a combination of glucose and fructose
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5. Complex Carbohydrates : Poly saccharides
Large carbohydrate molecules that are polymers of mono saccharides
Examples: starch glycogen, cellulose and chitin
Structure may be straight, twisted or branching chains
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6. Lipids include fats, phospholipids, waxes and steroids
fats serve as long-term energy storage molecules
phospholipids forms cell membranes
steroids include cholesterol and certain sex hormones
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7. FATS
Fats consist of a wide group of compounds that are generally soluble in organic solvents and largely insoluble in water.
Chemically, fats are generally triesters of glycerol and fatty acids
Fats may be either solid or liquid at normal room temperature, depending on their structure and composition.
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8. Structure of Fats
Are made up mainly of two types of molecules: fatty acids and glycerol
Fatty acids are long carbon-hydrogen chains with a carboxyl (COOH) group at one end
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9. Triglycerides
Are long-term energy storage molecules found in fat cells of adipose tissue
Composed of a glycerol molecule and three fatty acids
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10. Trans Fats
In cis-bonds, the two pieces of the carbon chain on either side of the double bond are either both “up” or both “down
In trans-bonds, the two pieces of the molecule are on opposite sides of the double bond, that is, one “up” and one “down” across from each other
fatty acids with trans bonds are carcinogenic, or cancer-causing.
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11. Phospholipids
Consist of a hydrophilic phosphate molecule and two hydrophobic fatty acid tails
Are and important part of cell membranes
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12. Steroids Consist of four linked carbon rings
Side chains attached to the rings make individual steroids unique
Include cholesterol, cortisone and the sex hormones estrogen and testosterone
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13. Proteins Direct and control the chemical reactions in life processes
Make up part of the cell membrane
Provide support and shape to cells
Function as hormones (chemical messengers)
Function as enzymes to speed up chemical reactions
Make up about ½ the body’s dry weight
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14. Amino Acids Proteins are polymers of amino acids
AA contain C, H and O like carbohydrates and lipids but also contain N
All AA’s have same basic structure
Each AA varies only in the structure of the R group
There are 20 different AA’s, eight of which are essential
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16. Protein Structure
Proteins can contain more than 1000 AA monomers and are known as a polypeptide
They are formed by dehydration synthesis forming peptide bonds between C and N atoms
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17. Proper function of proteins is determined by shape
There are four different levels of protein structure:
primary,
secondary,
tertiary and
quaternary
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18. Primary Protein structure
Is simply the order of AA’s in the polypeptide
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19. Secondary Protein Structures
Primary structure folds upon itself to form a-helix or b-pleated sheet patterns due to hydrogen bonding
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20. Tertiary Protein Structures
Are formed when the secondary structures fold over upon themselves and are held by covalent, ionic, hydrogen and non-polar bonds
The covalent bonds are disulfide bridges between Sulphur-containing AA’s
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21. Tertiary Protein Structure
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22. Quaternary Protein Structure
Occurs when two or more polypeptide chains combine to form the protein
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23. Protein Denaturation
Exposing a protein to heat, radiation or change in pH will alter its shape
Physical or chemical factors that disrupt the bonds between the amino acids changing the shape of the protein is called denaturing
Sometimes removing the factor allows the protein to assume is original shape
When the change is permanent coagulation has occurred
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24. Nucleic Acids Form the hereditary molecule DNA and RNA
Are polymers formed from monomer molecules called nucleotides
Nucleotides are made up of three subunits: a nitrogen-containing base, a five-carbon pentose sugar molecule and a phosphate group
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25. Nitrogenous bases
There are five nitrogenous bases, adenine, guanine (the purines), cytosine, thymine and uracil (the pyrimidines)
Thymine is present only in DNA and uracil is present only in RNA
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26. Nucleotide Bases
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27. DNA Structure
The DNA molecule is made up with the outer backbone of the sugar and phosphate group while the bases point inward
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28. Double and triple hydrogen bonds link the bases of the two chains
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29. Adenosine Triphosphate (ATP)
Is an important nucleotide found in the cell
Is a monomer Consisting of three phosphate groups attached to the ribose
ATP is the energy providing molecule of the cell and when the third phosphate group is split off by hydrolysis a net release of energy results
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