Chemistry of Cells

Has nothing to do with being naturally occurring!!

Carbon skeletons vary in length. Branching. Skeletons may be unbranched or branched. Butane Isobutane Propane Ethane Double bonds. 2-Butene Skeletons may have double bonds, which can vary in location. Cyclohexane Length. 1-Butene Benzene Skeletons may be arranged in rings. Rings. These are hydrocarbons

Study molecules important to life 4 Main Groups

What elements do they contain??????

1) Monosaccharides (Simple sugars) Examples : -glucose - fructose BLOOD SUGAR FOUND IN FRUITS Function  energy (readily available) - Ribose found in RNA

Structure : Glucose Elements? Shape?

Dehydration reaction -build larger molecules (polymers) by adding additional subunits (monomers)

Hydrolysis reaction -breaks the polymer down by adding water

Disaccharides Examples: –Sucrose –Lactose –Maltose Functions - Energy Structure: formed from the joining of two monosaccharides Maltose

General Structure: Many monosaccharides linked together Examples: Cellulose Monomer = glucose Function: structural component of cell walls Polysaccharides

Starch –Made of glucose monomers –Found in plants –Energy storage for plants

Glycogen Glucose monomers How animals store glucose –In liver and muscles

Fig. 3-7 Starch granules in potato tuber cells Glycogen granules in muscle tissue Cellulose fibrils in a plant cell wall Cellulose molecules Glucose monomer GLYCOGEN CELLULOSE Hydrogen bonds STARCH

Chitin Found in the exoskeletons of arthropods Function????

Proteins structure Are polymers Made from chains of amino acids Linked by peptide bonds –Those bonds form through dehydration reaction

Fig. 3-12a Carboxyl group Ami N o group Structure of an amino acid

Fig. 3-12c-1 Carboxyl group Amino acid Amino group Amino acid

Fig. 3-12c-2 Carboxyl group Amino acid Amino group Amino acid Peptide bond Dipeptide Dehydration reaction Build the polypeptide (protein) by dehydration reactions connecting the carboxyl group of one amino acid to the amino group of the other amino acid.

Fig. 3-12b Leucine (Leu) Hydrophobic Serine (Ser) Hydrophilic Aspartic acid (Asp) Different amino acids have different properties. Help to determine the overall shape of the protein

Functions Structural proteins  collagen, keratin, cell skeleton Storage  ovalbumin Transport  cell membrane transport protein, hemoglobin Regulation  hormones (insulin) communication  receptor proteins on nerve cell membranes Movement  in muscles Defense  antibodies enzymes  molecules that accelerate chemical reactions

Hemoglobin

collagen Insulin

actin myosin

Nucleic Acids Are polymers made of linked nucleotides Examples are DNA and RNA

Fig. 3-8a

Lipids Diverse group of hydrophobic molecules Include fats, phospholipids, and steroids General structure of a fat

3 fatty acid chains

Fig. 3-8b Fatty acid Glycerol Built by dehydration reactions

Fatty acids (and the fats that contain them) can be saturated or unsaturated Saturated with hydrogens

Amount of Hydrogens Shape of tails Presence of double bonds Solid or liquid (room temp) Source/ examples Saturated Unsaturated

Functions of fats Energy Cushion insulation

Phospholipids Structure: Similar to fats, but a fatty acid is replaced by a phosphate group Function Are a major component of plasma membranes

testosterone estrogen cholesterol progesterone 4 fused rings

Study molecules important to life 4 Main Groups