carbohydrates (sugars)
DESCRIPTION
Carbohydrates (sugars). Classified based on # of simple sugars C H O in 1:2:1 ratio Major nutrients for cells; ie glucose Produced by photosynthetic organisms Store energy in chemical bonds C skeletons raw materials for other organic compounds. Carbohydrates-disaccharides. - PowerPoint PPT PresentationTRANSCRIPT
Carbohydrates (sugars)
• Classified based on # of simple sugars
• C H O in 1:2:1 ratio
• Major nutrients for cells; ie glucose
• Produced by photosynthetic organisms
• Store energy in chemical bonds
• C skeletons raw materials for other organic compounds
Carbohydrates-disaccharides
Disacch.Monomers
Maltose glu + glu
Lactose glu + galac
Sucrose glu + fru
Carbohydrates: Polysaccharides
• 2 Important biological functions:– Energy storage (starch, glycogen)– Structural support (cellulose, chitin)
Storage Polysaccharides
• Starch = glucose polymer, for energy storage in plants– Helical glucose polymer– Most animals have enzymes to hydrolyze it– Major sources in
Human diet are potatoes
And grains
Storage Polysaccharides
• Glycogen = glucose polymer, for energy storage in animals
• Branched molec.
• Stored in muscle
and liver of humans
and other vertebrates
Structural Polysaccharides
• Cellulose = linear unbranched polymer – Major structural component of plant cell walls– Differs from starch in its monomer linkage– Cannot be digested by most organisms
Structural Polysaccharides
• Chitin = structural polysacch.; a polymer of an amino sugar (nature’s plastic)
• Forms exoskeleton of Arthropods
• Found as cell walls in fungi
Lipids
Diverse group of organic compounds that are
insoluble in water
Includes animal fats,
plant oils, steroids,
phospholipids
Made of fatty acids
and glycerol
Fat
• Saturated• All single bonds
• Solid at room temp• Animal fats
• Unsaturated• One or more double
bonds between carbons• Liquid at room temp• “Vegetable” or plant oils
Useful functions of fat
• Energy storage
• More compact fuel reserve than carbo.
• Cushions vital organs in mammals
• Insulates against heat loss
Phospholipids
• Component of cell membranes (bilayer)
• 2 fatty acids & phosphate group
• Amphipathic behavior in water
Steroids
• Lipids w/ 4 fused carbon rings and various functional groups
• Cholesterol important as precurser to other steroids; and enhance membrane fluidity
Proteins
• Complex polymers of amino acids
• Abundant: make up 50% or more of dry wt
• Varied functions in cell: structure, metabolism, transport, signaling, movement, defense
• Each has unique 3-D shape
• Made of only 20 different amino acids
Nucleic Acids
• Deoxyribonucleic Acid (DNA)
• Can replicate itself and be passed from one generation of cells to the next
• Genes are segments of DNA that code for protein
• Ribonucleic Acid (RNA)
• Functions as mediator between genotype and phenotype
• 3 functional forms carry out “protein synthesis”