Disaccharides Hydrolysis and Properties

Carbohydrates

• Source of energy that are aldehyde alcohols (aldose sugar) or ketone alcohols (ketose sugar).
• Aldehydes are RCOH, with the double bond oxygen at the first carbon, e.g., aldo hexose with 6 carbons
• Ketones are RCOR, with the double bond oxygen at the second or third carbon, e.g., keto aldose with 6 carbons.
• General formula: Cₙ(H₂O)ₙ, e.g., C₆H₁₂O₆

Identifying Levo or Dextro Sugar

• Look at the penultimate carbon (second to last carbon)
• If OH is on the right, it’s dextro.
• If OH is on the left, it’s levo.

Photosynthesis

• A biological process that changes electromagnetic energy into chemical energy
• Plants and some bacteria and algae produce glucose and oxygen from carbon dioxide and water with light
• Carbohydrates are products of photosynthesis
• Glucose is used during respiration to release energy for the plant's life processes
• Some glucose is converted by plant cells into starch for storage.
• Dead plants are used as biomass due to stored chemical energy
• Light Reactions (light-dependent): convert electromagnetic energy into chemical potential, using ATP and NADPH, initiated by pigments
• Dark Reactions (light-independent/Calvin cycle): Utilize the energy from light reactions to fix carbon dioxide into sugar, needing ATP and NADPH, the product is carbohydrates, oxygen, and water

Carbon Fixation (Stage 1 of Calvin Cycle)

• Fixes inorganic carbon into an organic molecule in the stroma of the plant using 3 CO₂, RUBISCO enzyme, and 3 RUBP (Ribulose-1,5-Biphosphate carboxylase)
• Per 1 mole of CO₂ and RUBP, 2 moles of 3-phosphoglycerate are produced (6 moles total).

Reduction (Stage 2 of Calvin Cycle)

• A substance is reduced when another is oxidized.
• Uses the chemical potential from the light reaction.
• G3P has an H added (gain of electron), so 3-phosphoglycerate was reduced
• Six moles need ATP and NADPH
• ATP oxidizes to ADP (1 phosphate was decreased so an electron is also removed)
• Electrons are transferred by the phosphate group
• NADPH to NADP+ is an oxidation process.

Regeneration (Stage 3 of Calvin Cycle)

• 1 G3P goes to the cytoplasm, leading to secondary plant substances like tannins, flavonoids, and amino acids
• 5 molecules continue in the Calvin cycle for RUBP regeneration.
• G3P to RUBP is reduction because ATP was oxidized to ADP.
• There are 15 total carbons (G3P and RUBP)

Classification of Carbohydrates

• Monosaccharides: crystalline, sweet, cannot be hydrolyzed into simpler sugars
• Oligosaccharides: (oligo = few, sacchar = sugar), made of 2-10 sugar units, includes disaccharides, trisaccharides, etc.
• Polysaccharides: over 10 sugar units; most are tasteless and fibrous

Number of Carbon Atoms

• 2 Carbons: Diose - Hydroxyacetaldehyde
• 3 Carbons: Triose - Glyceraldehyde, dihydroxyacetone (ketose)
• 4 Carbons: Tetrose - Erythrose, erythulose (aldose)
• 5 Carbons: Pentose - Ribose, xylulose, xylose (ketose)
• 6 Carbons: Hexose - Gluc, Fruc, Mann
• 7 Carbons: Heptose - Sedoheptulose
• 8 Carbons: Octose
• 9 Carbons: Nonose - Neuraminic acid
• 10 Carbons: Dectose

Classifications of Sugars

• Diose: simplest sugar
• Triose/Tetrose: doesn’t occur freely
• Pentose: can occur freely, byproducts of hydrolysis, e.g., ribose (aldose), xylose (aldose) ribulose (ketose), xylulose (ketose)
• Hexose: first detectable sugar synthesized by plant; in free state: dextro fructose (levulose), dextro glucose (dextrose); found in sweet fruits, honey, and invert sugars

D-xylose (pentose sugar)

• Obtained by boiling corn cobs, straw, or similar materials with dilute acid to hydrolyze the xylan property or xylan polymer and is a diagnostic agent to evaluate the intestinal absorption.
• Relative xylose excretion in urine indicates intestinal malabsorption, such as celiac disease, Sprue, Crohn's disease, radiation enteritis

D-glucose/dextroglucose

• 80-120 mg% in your blood, also known as D-glucopyranose, Dextrose, Grape sugar and Blood sugar and it occurs naturally in grapes and other fruits
• Usually obtained by controlled enzymatic hydrolysis of starch that is used as a nutrient and an ingredient in dextrose injections and tablets
• Can also be present in anticoagulant citrate phosphate dextrose solution.

Dextrates

• Obtained by controlled enzymatic hydrolysis of starch and purified saccharides that contain NLT 93% dextrose and it's used as a sweetening agent

Liquid Glucose

• Obtained by the incomplete hydrolysis of starch, prepared by controlled acid hydrolysis of cornstarch, which is used as pharmaceutic necessity

Calcium Gluconate

• Calcium salt of gluconic acid that is obtained by fermentation, soluble in cold water, less irritating, and it's an electrolyte replenisher

Calcium Gluceptate and Calcium Levulinate

• Calcium salts of 7 and 5 carbon acids that can be prepared from starch or cane sugars and are used to obtain the therapeutic effects of calcium.

Ferrous Gluconate

• Ferrous salt of gluconic acid is a hematinic for iron deficiency anemia that causes less gastric distress.

Fructose/levulose

• Found in sweet fruits, honey from Apis mellifera, also known as d-fructose, d-fructopyranose, or fruit sugar obtained by the inversion of sucrose, is a ketone sugar that occurs naturally and the hydrolysis of inulin.

High-Fructose Sweeteners

• Prepared by controlled enzymatic isomerization of glucose
• High-fructose corn syrups contain up to 90% fructose
• The difference is in spatial arrangement of atoms

Galactose (Brain Sugar)

• Rapidly absorbed, but if an individual is deficient with the enzyme, it will accumulate to a higher level in blood and damage organs
• Known as galactosemia

Disaccharides

• yield 2 monosaccharide molecules on hydrolysis

Sucrose

• In fruit juices, sugar cane, sugar beet, the sap of certain maples and example of disaccharide that occurs abundantly in plants
• Creates an invert sugar consisting of equimolecular quantities of glucose and fructose

Maltose

• Yield 2 units of glucose + 1 fructose upon hydrolysis
• Produced in large quantities by the hydrolysis of starch during the germination of barley and other grains such as Barley - Hordeum vulgare (Poaceae), is an example of a reducing sugar used in baking and brewing

Cellobiose

• Enzymatic breakdown of cellulose brings cellobiose and the enzymatic breakdown requires 2 units of glucose
• Cellulose from plant cell walls; can be isolated from Cotton Gossypium hirsutum

Trehalose

• The enzymatic breakdown of plants, bacteria, ergot, fungi brings 2 units of glucose with non-reducing sugar which is for preservative

Sophorose

• Not commonly found, beta 2, 2 linkage which it can allow beta cells to occur
• treating with dilute acid and purified with charcoal

Primeverose

• Sources: Meadow worth, Filipendula ulmaria, hydrolysis of spiraein which is a reducing sugar

Lactose

• If has enzyme to breakdown, turns into 2 simple sugars such as glucose and galactose, which is semi-synthetic sugar prepared by alkaline rearrangement of lactose
• semi-synthetic sugar prepared by alkaline rearrangement of lactose

Lactulose

• semi-synthetic sugar prepared by alkaline rearrangement of lactose.

Raffinose

• It increases the growth of lactic aids and can be obtained from cotton seeds

Mannetrisoe

• Has 1 galactose 1 lactose

Melezitose

• Honey dew that is produced

planteose

• Can be fructose and lactose

Stachyose

• Cannot be digested.

Glycogen

• is the storage form of a carbohydrate in the animals is well humans,formed through glycogenesis (search pathway)

Cellulose

• not metabolized by the human body

Artificial Tears

• Solutions can be used for contact lenses

Glycolysis

• intermediate reaction - (acetyl coa and nadph produced)