Week 3 Lecture 3, Carbohydrates and Lipids:

Simple Sugars (Saccharides)-Sugars with the same number of carbons are structural isomers. -Some simple sugars are metabolized to provide energy to cells.

Simple Sugar Structure-Simple sugars are usually found in a ring form. -Label the carbons starting at the carbonyl.

Disaccharides-Chain 2 saccharides together with a glycosidic bond (linkage) using a dehydration reaction.

Other Common Disaccharides

-Malt is in beer and chocolate (malts). Lactose is found in milk.

Artificial Sweeteners

Polysaccharides-Long polymers of saccharides-Store and provide energy-Structural-Signaling

Glycogen-Polymer of glucose-Formed in human liver and skeletal muscle to store energy. -Hydrolyzed to provide energy to the body.

Starch-Less branched polymer of glucose. -Used for glucose storage in plants. -Potato tuber – specialized plant organ that stores energy.

Cellulose-Unbranched glucose polymer. -Found in plant cell walls. -Undigestible except by some bacteria and fungi. -“Insoluble fiber”

Chitin-Polymer of modified glucose (N-acetyglucosamine)-Anthropod (insects, shrimp, crab) exoskeleton

Lipids-Not polymers-Large molecules formed by dehydration reactions-All are hydrophobic

Fat-Energy storage-Made by adipocytes (fat cells)-Easter linkage – between a carboxyl and hydroxyl group

Phospholipids

Lipid Bilayers-Form lipid bilayers that make up cellular membranes.

Steroids-Common Structure

Cholesterol-Incorporates into lipid bilayers-Stabilizes membrane fluidity

Steroid Hormones

Week 3 Lecture 4, Localization and Variation of MacromoleculesLocalization of Nucleic Acids-Prokaryotes-Nucleoid region-Eukaryotes

-Nucleus-Mitochondria and chloroplasts

-RNA is also found in the cytoplasm

Localization of Protein-Everywhere!!

-embedded in membranes-in the cytoplasm-inside organelles -outside cell

Localization of Lipids-All membranes

-plasma membrane-organelle membranes-eukaryotic flagellum and cilia

Localization of Carbohydrates-Complex carbohydrates are typically outside of the cell or in specialized regions inside. -Simple sugars are dissolved in the cytoplasm.

Modification of Macromolecules-Numerous modifications can be made though hydroxyl groups.

-Other monomers-Other macromolecules-Lipid chains-Functional groups-Small molecules

Modification of Proteins-Phosphorylation

-Addition of a phosphate group onto a free hydroxyl group on a protein. -Can be used to turn proteins on or off. -Particularly useful in cell signaling.

Modification of Lipids-With carbohydrates

Modification of DNA-Epigenetics (Methylation)

Take Home Message-DNA is in found in the nucleus, mitochondria, and chloroplasts. -RNA is also found in the cytoplasm. -Protein is everywhere!-Lipids are primarily in membranes. -Polysaccharides are primarily outside of the cell. -Monosaccharides are in the cytoplasm. -Macromolecules can be modified to change their functions.