BIOCHEM

• Organic chemistry


  The study of structure, properties, compositions, reactions, and preparation of carbon-containing compounds
• Biochemistry


  The chemistry of living matter
• Physiological chemistry


  Animal biochemistry, which is an outgrowth of animal physiology
• Phytochemistry


  Plant biochemistry
• Plants are synthetic, animals are decompositional
• Plants were chiefly concerned with building up complex compounds from the simple raw materials obtained from the soil and air
• Plants oxidize their reserve food supplies, just as animals oxidize their foods
• Animals are constantly synthesizing complex compounds from the simple molecules resulting from the decomposition of foods in the body
• There is no fundamental difference between chemical processes in animals and plants
• Protoplasm


  A jellylike, viscous substance found in animal and plant cells, the basic substance concerned with life
• Protoplasm has an amount of water from 70 to 90 percent
• About 1 percent of protoplasm is ash, which is composed of sodium, potassium, calcium, magnesium, iron, phosphates, carbonates, sulfates, and chlorides in comparatively large amounts together with traces of such elements as copper, manganese, zinc, silicon, tin, and iodine
• From 10 to 25 percent of protoplasm is made up of organic matter (carbohydrates, the lipids, proteins, and a miscellaneous, group of compounds commonly called extractives)
• Living things


  • Have the power within themselves to move
  • Grow
  • Are irritable; in other words, they respond to stimuli
  • Have the power of reproduction
  • Are constantly undergoing chemical changes known as metabolism
• Growth is the result of the absorption of food and its conversion into new tissue
• Motion requires energy, which comes from the oxidation of foods
• The oxidation of foods, which involves the utilization of oxygen and the liberation of carbon dioxide, is a prominent phase of metabolism known as respiration
• Metabolism and reproduction are perhaps the most universally accepted criteria of life
• 3 Classes of Organic Compounds

  • Carbohydrates
  • Proteins
  • Lipids

  
• Carbohydrates


  The most abundant constituent of many foods, the source of a large part of the heat and mechanical energy of the body, and a part of protoplasm essential for the building of body tissue
• Carbohydrates are composed of carbon, hydrogen, and oxygen, with the hydrogen and oxygen usually in the proportion of two to one, just as in water
• Not all organic compounds containing hydrogen and oxygen in the proportion found in water are carbohydrates
• Some carbohydrates, such as rhamnose (C6H12O5), do not contain the usual proportions of hydrogen to oxygen
• Sources of Carbohydrates


  • Cellulose
  • Starches
  • Simple sugars

  
• Cellulose


  The most abundant carbohydrate found in nature, the main constituent of woody tissue, the material which gives plants their structure

  
• Starches


  Also occur abundantly in nature, the main source of carbohydrate in the diet
• Simple sugars


  Such as glucose, sucrose, and lactose, are also important sources of carbohydrate in nutrition

  
• Classification of carbohydrates


  • Monosaccharides/Simple sugars
  • Disaccharides
  • Polysaccharides

  
• Monosaccharides/Simple sugars


  The simplest carbohydrates, derivatives of polyhydric alcohols where an alcohol group is oxidized to an aldehyde or ketone

  
• Types of monosaccharides


  • Aldoses (aldehyde alcohols)
  • Ketoses (ketone alcohols)

  
• 1. glucose and D-fructose


  The most common simple sugars, oxidation products of the polyhydric alcohol D-sorbitol

  
• Classifications of monosaccharides


  • Dioses (2 carbons)
  • Trioses (3 carbons)
  • Tetroses (4 carbons)
  • Pentoses (5 carbons)
  • Hexoses (6 carbons)
  • Desoxy sugars

  
• Dioses


  Simple carbohydrates with two carbons, the first oxidation product of a polyhydric alcohol, with no asymmetric carbon atom and only one form
• Trioses


  Simple carbohydrates with three carbons, oxidation products of the trihydric alcohol glycerol, can be aldoses or ketoses, have optical isomers

  
• Tetrose, pentose, hexose


  Simple carbohydrates with 4, 5, and 6 carbons respectively, can be derived from D- or L-glycerose

  
• Desoxy sugars


  Compounds considered true sugars in which one or more of the OH groups have been replaced by H, such as rhamnose (6-desoxy-L-mannose)

  
• Pentoses


  Sugars with five carbon atoms, four aldopentoses found in nature (D-arabinose, L-arabinose, D-xylose, D-ribose), not fermented by bread yeast
• Hexoses


  The most important carbohydrates from the standpoint of foods and nutrition, four important ones (D-glucose, D-mannose, D-galactose, D-fructose)

  
• 1. glucose has 4 asymmetric carbon atoms and 16 isomers, D-fructose has 3 asymmetric carbon atoms and 8 isomers

  
• Molisch's test


  A test for carbohydrates in general, based on the production of furfuraldehyde and its reaction with α-naphthol