Chapter 2: Molecules of Cells Flashcards
What do carbohydrates include?
Simple sugars and polysaccharides
What are some functions of polysaccharides?
Storage forms of sugars Form structural components of the cell Cell recognition Transport proteins intracellularly Protein folding
What are monosaccharides?
Simple sugars that are the major nutrients of the cell with the formula (CH2O)n
What is glucose?
Simple 6-carbon sugar that provides principle source of cellular energy with the formula C6H2O6.
Ions and polar molecules are ____ in water
Hydrophillic
Nonpolar molecules are ______ in water
Hydrophobic
What are the four classes of organic molecules?
Carbohydrates
Nucleic Acids
Proteins
Lipids
What are oligosaccharides?
Polymers with few sugars
What are polysaccharides?
Macromolecules that have polymers of hundreds or thousands of sugars
What is the result of monosaccharides being joined together by dehydration reactions?
Glycosidic bonds
What are the two common polysaccharides? Which type of eukaryotic cells are they located in?
Glycogen: stores glucose in animal cells
Starch: stores glucose in plant cells
What is cellulose?
The main structural component of plant cell walls. Composed entirely of glucose molecules in the beta configuration
What is the advantage of beta(1-4) configuration?
Linkages cause cellulose to form long extended chains that pack side by side to form fibers of great mechanical strength
What is chitin?
The animal version of cellulose. It forms the exoskeletons of crabs and insects.
What are the main roles of lipids?
Energy storage
Major component of cell membranes
Important in cell signaling as steroid hormones and messenger molecules
What are fatty acids?
Long hydrophobic hydrocarbon chains (16 or 18 carbons) with a carboxyl group (COO-) at one end
What are unsaturated fatty acids?
Have one or more double bonds
What are saturated fatty acids?
Have no double bonds.
How are fatty acids stored?
Stored as triacylglycerols (triglycerides/fats)
What are triacylglycerols (triglycerides/fats)
Three fatty acids linked to a glycerol molecules. Insoluble in water and accumulate as fat droplets in cytoplasm. Can be broken down for energy.
Why are fats important?
Yield more energy than carbs which allows energy to be stored in less than half the body weight which is important for the mobility of animals.
What are phospholipids?
The principle components of cell membranes in which two fatty acids are joined to a polar head group.
What is the only nonglycerol phospholipid in cell membranes?
Sphingomyelin (polar head formed from serine)
What are glycolipids composed of?
Two hydrocarbon chains and a carbohydrate polar head group (present in the cell membrane)
