Carbohydrates have reactions {carbohydrate reactions}. Mitochondria have citric acid cycle (Krebs cycle). Cytoplasm and mitochondria have gluconeogenesis. Cytoplasm has glycolysis. Mitochondria have oxidative phosphorylation. Cytoplasm has pentose phosphate pathway. Mitochondria have respiratory chain.
organs
Brains use glucose and do not store fat or glycogen. Muscle stores glycogen and uses glucose when active. Heart muscle uses ketone bodies. Liver puts glucose into blood and regulates glucose blood level.
Reactions {anaerobic} can require no oxygen.
TCA cycle uses oxygen {aerobic respiration} to make carbon dioxide.
Acetyl-CoA reactions {Claissen condensation} can lengthen carbon chains by branching. Acetyl-CoA ketone, CH3-CO-S-CoA [3 is subscript], can lose hydrogen when CoA leaves, CH3-CO-, and separate charges to make (C-H2)-(C+O) [2 is subscript and - and + are superscripts]. Ketone carbon is positive, and methyl carbon is negative. Separated charges attack dicarboxylic acid, HOOC-CH2-COOH [2 is subscript], to add ketone, HOOC-(CH2C-H2C+O)-COOH [2 is subscript and + and - are superscripts]. Adding water molecule neutralizes carbon and makes branched carbon chain, HOOC-CHCH2COOH-COOH [2 is subscript], as hydrogen gas leaves.
Reactions {reverse aldol condensation} {condensation reaction, carbohydrate} can lengthen carbon chains by two carbons.
ketol-enol
Proton can transfer from -CO-CH2OH ketol last carbon to next-to-last carbon, to make enol double bond between carbons and alcohol on next-to-last carbon: -COH=CHOH. Enol can add water molecule to make separated charges: -(H2OC+OH)-(C-HOH) [2 is subscript and + and - are superscripts]. Last carbon becomes negative, and next-to-last carbon becomes positive.
aldol
Enol with separated charges can attack aldol, -CHOH-CHO, carbonyl double bond to single-bond carbonyl carbon and carbanion: -CHOH-(C-OH)-CHOH-(H2OC+OH)- [2 is subscript and + and - are superscripts]. Positive charge is still on next-to-last enol carbon, and negative charge is on last aldol carbon.
proton transfer
Water leaves, and proton transfers from positive charge to carbanion and makes atoms neutral: -CHOH-CHOH-CHOH-CHOH-.
Glucose can convert to ethanol and carbon dioxide, using no oxygen {fermentation}|. Glucose converts to pyruvate. Pyruvate converts to acetaldehyde by losing carbon dioxide. Acetaldehyde reduces to ethanol using NADH. Berzelius described fermentation [1837].
Glucose can convert to pyruvate and then to lactic acid {glycolysis}| {Embden-Meyerhof pathway}. Glycolysis makes more ATP than it uses and is anaerobic, requiring no oxygen. Glycolysis enzymes float free in cytoplasm. In first part, glucose becomes glyceraldehyde-3-phosphate by adding two ATPs to ends and splitting into two molecules. In second part, glyceraldehyde-3-phosphate becomes pyruvate and makes four ATPs. Pyruvate makes lactic acid by adding NADH.
Isocitrate makes glyoxalate, and glyoxalate makes malate {glyoxalate cycle}, if acetyl-CoA is present. Glyoxysomes make succinate, which is precursor for fatty-acid synthesis.
Glucose-6-phosphate becomes 6-phosphogluconate by oxidation {phosphogluconate pathway} {pentose phosphate pathway} {hexose monophosphate shunt}. Aldehyde becomes carboxyl. NAD+ becomes NADPH. 6-phosphogluconate makes pentoses, such as ribose-5-phosphate, for nucleotides. Hexose monophosphate shunt in reverse makes hexoses from pentoses for extra energy. Pentose phosphate pathway is in photosynthesis dark reaction.
Sugars can isomerize by keto-enol tautomerism at carbonyl {isomerization}|.
By isomerization {keto-enol isomerization}, enol can become ketol, and ketol can become enol. Keto-enol isomerization must polarize, with lysine, cysteine, or serine.
At cysteine, aldehyde can oxidize to carboxylic acid using two NAD+ {oxidation, carbohydrate}. R-CHO -> R-CHOH-S-cys + 2 NAD+ -> R-CO-S-cys + 2 NADH -> R-COOH. Sugars can oxidize to makes acids: ascorbic acid, gluconic acid, uronic acid, and phytic acid {oxidized sugar}. Sugar aldehyde or ketone group can reduce to alcohol group to make glycerol, inositol, sorbital, and mannitol reduced sugars. Glycerol and inositol bind fatty acids. Sorbital and mannitol are food additives.
Hydrogen-ion transfer provides energy to convert ADP to ATP {phosphorylation}. ADP makes ATP {oxidative phosphorylation}, using hydrogen-ion gradient set up by respiratory chain in mitochondria inner membrane. Channels through membrane allow hydrogen ions to flow past ATPase, which uses electric and flow energy to phosphorylate ADP. ADP controls process by controlling coupling between FAD+ to FADH2 [2 is subscript] and NAD+ to NADH, by folding inner membrane more or less. Arsenate or dinitrophenol destroys pH gradient. Oligomycin binds to ATPase.
Carbon dioxide, water, and sunlight can make oxygen and glucose {photosynthesis}|.
process
First, light reacts with water, NADP+, and ADP to make oxygen, NADPH, H+, and ATP {light phase}. Light oxidizes pigments, to release electron. Donated electron adds to NADP+. Electron transport chain and oxidative phosphorylation make ATP and oxygen. Then carbon dioxide, NADPH, H+, and ATP make glucose, NADP+, and ADP {dark phase}, with no light required.
pigments
Chlorophyll a absorbs orange light, and chlorophyll b absorbs red light, making plant green. Yellow, red, or purple carotenoid pigments absorb at different wavelengths. Xanthophyll carotenoid absorbs yellow. Physobilin carotenoid absorbs blue or red.
Older system absorbs light at 710 nanometers and makes ATP but no oxygen. Newer system absorbs light at 680 nanometers and makes oxygen.
bacteria
Nitrogen-fixing bacteria use photosynthesis to make nitrogen into ammonia. Nitrate-fixing bacteria use photosynthesis to make ammonia. Sulfur bacteria use photosynthesis to make sulfates.
NADH and NADPH from glycolysis, TCA cycle, and other oxidations reduce oxygen to water in mitochondria {respiration, metabolism}. Hydrogen ions increase inside mitochondria and make pH gradient across mitochondrial membrane.
respiratory chain
Aerobic reduction reactions {respiratory chain} make the following compounds: FMNH2 [2 is subscript], ferrous iron, coenzyme Q, cytochrome b, iron-sulfur bond, cytochrome c, cytochrome c1, cytochrome a, cytochrome a3, and water from oxygen.
phosphorylation
Oxidative phosphorylation links to respiratory chain at three places: coenzyme Q reduction, cytochrome c reduction to cytochrome c1, and oxygen reduction to water. At the three steps, respiratory chain places hydrogen ions on mitochondria inner-membrane outside.
poisons
Hydrogen cyanide, carbon monoxide, and hydrogen sulfide inhibit oxygen reduction to water.
Fruit can increase sugar and decrease complex carbohydrates {ripening}|. After picking, starch builds up, and sugar breaks down. Ethylene can ripen fruit.
Citrate and ATP can make acetyl-CoA. Acetyl-CoA enters cycles {TCA cycle} {tricarboxylic acid cycle} {citric acid cycle} {Krebs cycle} and becomes two carbon dioxides and four NADH hydrogens. TCA cycle makes citrate, isocitrate, alpha-ketoglutarate, succinyl-CoA, succinate, fumarate, malate, oxaloacetate, and citrate again. These are mostly three-carbon carboxylic acids. Pyruvate, carbon dioxide, and ATP can make oxaloacetate and malate, which can enter cycle.
purpose
NADH hydrogens are for reduction reactions.
aerobic
TCA cycle uses oxygen to make carbon dioxide.
5-Chemistry-Biochemistry-Carbohydrate
Outline of Knowledge Database Home Page
Description of Outline of Knowledge Database
Date Modified: 2022.0225