BIMs or Biologically Important Molecules can be split into four categories: Proteins, Carbohydrates, Lipids, and Nucleic Acids. Each of these groups is composed of different subunits and each performs different tasks within the human body.

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Composed of: Amino Acids
  • Found in white blood cells and tears, it helps destroy harmful bacteria
  • Used for structural support
  • Transportation of other substances
  • Signaling from on part of the organism to another
  • As an enzyme, protein acts as a catalyst in some metabolic reactions
A protein's shape determines its function
Proteins are made from 20 kinds of amino acids which interact within the protein's structure to form it's specific shape.
Primary Structure-is composed of the proteins amino acid sequence
  • Amino acids are linked by peptide bonds
  • A peptide bond is the bond that occurs when a carboxyl-group carbon covalently bonds to an amino-group nitrogen following dehydration synthesis.
Secondary Structure-is the polypeptide (a chain of amino acids linked by peptide bonds) coiling or folding that is a result of hydrogen bonding.
  • Alpha helix is the structural name for a coiled polypeptide
  • Pleated sheet is the structual name for a folded polypeptide
Tertiary Structure-is the shape of a polypeptide and is the result of interactions between the R-groups withing the alpha helix and pleated sheet formations of the protein
  • R-groups, also know as functional groups, have four types:
Hydroxyl O-H
Carbonyl C=O
Carboxyl OH-C=O
Amino H-N-H
Note: there is one formation (H-C=O) that falls between Hydroxyl and Carbonyl and is found in Aldehyde compounds

Quaternary Structure-is the overall shape of the protein structure and results from the combination and interactions between the polypep

*These four levels apply to general proteins. There are also globular proteins, and fibrous proteins.

external image sucrose.jpg
subunit: monosaccharides
- used in body as fuel to make ATP
- allow chemical reactions in body
- covalently bonded molecules of C, H, and O
- hold lots of energy
- follow the formula Cx(H2O)x
- easily form chains when combined in body (2 carbs= disaccharide, 3 or more carbs= polysaccharide)
- assembled by plants using photosynthesis
external image lipid2.jpg
subunit: fatty acids
- used in the body to store energy
- protect cells, organs
- dissolve vitamins (lipids are necessary to ingest vitamins)
- create outer membrane of cells
- covalently bonded molecules of C,H, and O
- saturated and unsaturated fats
Saturated Fats:
- straight chain of hydrocarbons
- use the "maximum" number of hydrogens
- usually solid at room temp.
Unsaturated Fats:
- have double bonds, so kinked
- double bond prevents chain from bonding with maximum number of hydrogens
- usually liquid at room temp, b/c the kinks in the chains prevent it from packing in tightly and solidifying

Nucleic Acids
external image ds_DNA.jpg
subunit: nucleotides (contains pentose sugar, nitrogenous base, and phosphate group)
- store information
- direct activity in the cell
- blueprints for proteins
-Covalent bonds of C, H, O, N, S

For more information, go to:
The Life of a Turkey
Chapter 3 Vocabulary