Carbohydrates

• What is the major food source and energy supply for the body?

  Carbohydrates
• Where are carbohydrates primarily stored in the body?

  As liver and muscle glycogen
• What does the name carbohydrate literally mean?

  Carbon, hydrogen, and oxygen
• What is the general formula for carbohydrates?

  Cx(H2O)y
• What functional groups do all carbohydrates contain?

  C=O and -OH functional groups
• What is the typical hydrogen-oxygen ratio in carbohydrates?

  1. 1
• What are the two forms of carbohydrates?

  • Aldose
  • Ketose
• What is the primary function of carbohydrates in organisms?

  They are the primary source of energy
• How do carbohydrates participate in cellular functions?

  As glycoproteins and glycolipids in cell membranes
• In what form are carbohydrates stored to meet immediate energy demands?

  As glycogen
• What are the four properties used to classify carbohydrates?

  1. Size of the base carbon chain
  2. Location of the CO functional group
  3. Number of sugar units
  4. Stereochemistry of the compound
• What are the classifications of carbohydrates based on the number of carbons?

  • Trioses (3 carbons)
  • Tetroses (4 carbons)
  • Pentoses (5 carbons)
  • Hexoses (6 carbons)
• How are carbohydrates classified based on the location of the CO functional group?

  • Aldose: terminal carbonyl group (e.g., glyceraldehyde, glucose)
  • Ketose: carbonyl group in the middle (e.g., dihydroxyacetone, fructose)
• What are the types of carbohydrates based on the number of sugar units?

  • Monosaccharides
  • Disaccharides
  • Oligosaccharides
  • Polysaccharides
• What are monosaccharides often referred to as?

  Simple sugars
• Can monosaccharides be further hydrolyzed?

  No, they cannot be further hydrolyzed
• What are the types of disaccharides and their components?

  • Sucrose: glucose + fructose
  • Maltose: glucose + glucose
  • Lactose: glucose + galactose
• What is the most common disaccharide referred to as table sugar?

  Sucrose
• What is lactose commonly known as?

  Milk sugar
• What is maltose formed from?

  Two units of glucose joined by an alpha bond
• What are polysaccharides and their types?

  • Polymers of monosaccharide units
  • Types:
  • Homopolysaccharides: same repeating units
  • Heteropolysaccharides: different repeating units
• What are some common polysaccharides?

  • Starch
  • Glycogen
  • Cellulose
• What do oligosaccharides contain?

  1. 10 monosaccharide molecules
• What is the Fischer projection used for?

  To represent carbohydrates with aldehyde or ketone at the top
• What is the Haworth projection?

  A representation formed when the functional group reacts with an alcohol group to form a ring
• What are the only two types of carbohydrates that contribute to human nutrition?

  Glucose and sucrose
• What are the pathways of glucose metabolism?

  1. Glycolysis: breakdown of glucose to produce energy
  2. Gluconeogenesis: production of glucose from non-carbohydrate sources
  3. Glycogenesis: formation of glycogen from glucose
  4. Glycogenolysis: breakdown of glycogen to produce glucose
• What are the intermediate products generated from glucose metabolism?

  Pyruvic acid, lactic acid, and acetyl-coenzyme-A
• What role does the liver play in glucose metabolism?

  Regulates blood-sugar levels through glycolysis
• What is the ultimate goal of the cell in glucose metabolism?

  To convert glucose to carbon dioxide and water
• What high-energy molecule is obtained during glucose metabolism?

  ATP
• What are the pathways involved in glucose metabolism?

  • Ebden-Meyerhof Pathway
  • Krebs Cycle
  • Pentose Phosphate Pathway
• What is the role of the pancreas in carbohydrate metabolism?

  • Functions as both an endocrine and exocrine gland
  • Secretes hormones like insulin, glucagon, and somatostatin
• What is the primary hormone responsible for the entry of glucose into the cell?

  Insulin
• Where is insulin synthesized?

  By the beta cells of the islets of Langerhans in the pancreas
• When is insulin normally released?

  When glucose levels are high
• What is the function of insulin in relation to glucose levels?

  It lowers or decreases glucose levels
• What metabolic processes does insulin promote?

  Glycogenesis and glycolysis
• What does insulin inhibit?

  Glycogenolysis
• What is the relationship between insulin and glucagon?

  They have a reciprocal relationship