Across 3 phyla, great homology (>90%) in our enzyme pathyways exist. The domains for energy production, synthesis and coordination are shared. See prior post: Animal Amour and Metabolic Networks
--Amino Acid metabolism
Plant Energy Conversion: Calvin Cycle
Plants produce energy for higher life forms to consume and spread seed. Flowering plants are only a recent blimp in the evolutionary timeline. Seeds in high-carbohydrate-containing fruit co-evolved with multi-cellular animals it appears.
From air (CO2) and light (sun UV energy) carbohydrates, fatty acids and proteins are biochemically produced. Magic?
The CALVIN CYCLE.
Plant Bio 101: Fructose, Glucose, Sucrose Produced from Calvin Cycle
How the Calvin Cycle Works Animation + Quiz (click)
Light is absolutely required. The Calvin Cycle cannot occur without UV energy, sunlight.
Fructose (monosaccharide) is first produced then interconverted to glucose (monosaccharide) with a one-carbon change, then sucrose is fused which can be transported throughout the plant. Sucrose (disaccharide) is fructose + glucose linked. Starch is complex carbohydrates linked together; digestion is the process of breaking down starch by our salivary amylases (enzymes = 'cutters'), our pancreatic enzymes and gut flora into glucose. Diagram courtesy of plant physiology Prof Ross Koning.
Table sugar = sucrose = fructose+glucose
Lactulose = galactose+fructose (see Dr. Ayers post)
Lactose = galactose+glucose (dairy)
Maltose = glucose+glucose
Starch = complex carbohydrate
High-Fructose-Corn-Syrup (HFCS) = fructose + contaminants (pesticides, GMO corn residues, LEAD)
Glucose is a 6-carbon chain Derivatized to Carbs, Protein, Fatty Acids
Outside of the Calvin Cycle, glucose can be made into other molecules for use into starches, cellulose, protein and fatty acids. Glucose is flexible. It can be made into so many useful things.
Plant products are ubiquitous and humans have figured out ingenious ways to use them for centuries outside of food and shelter:
--food (fruit, fats, lignans, roots/tubers, stems, leaves, etc)
--fatty acids (oils, biodiesel, fragrances)
--medicines (antioxidants, vitamins, herbals, rejuvenants, chemotx)
--musical instruments (wooden flutes, guitars, violins)
--clothing (cotton, hemp, etc)
--compost (nitrogen renewal, etc)
Plants -- Calvin Cycle; Animals -- GNG + Fat Burning
From single carbons from carbon dioxide (air) and light, plants can produce a 6-carbon ring known as glucose for energy and storage of energy (starch, fatty acids, protein) via photosynthesis and a special energy pathway known as the Calvin Cycle. ATP is used up in the process and light energy is absolutely mandatory.
On the other hand, animals have an advantage with the evolution of an analogous special energy pathway for glucose production, known as gluconeogenesis (GNG), without requiring sunlight. Unlike plants, animals do not require sunlight for production of energy and glucose, and therefore the advantage of more mobility and movement.
Mitochondria are absent in all lifeforms except the eukaryotic branch. Bacteria (prokaryotes) ARE mitochondria *haa*. Plants and animals hijacked their technology...aka, endosymbiosis...
Fat energy release provides almost four-times more energy per molecule. On a carbon-per-carbon basis, 33% more energy is produced (when I compare Stearate 18:0 and Glucose 6-carbon by pure stoichiometry, which is wrong but oh well).
Carbs. Glucose is equivalent to only ~1 tsp (5 grams) in our blood. Glycogen is stored ~100-200 grams in muscles and ~400-500 grams in the liver. Less than one kilo of carbs is stored and running through our veins.
Fat. For 10-20% body fat (composition like most omnivores or carnivores), an average human carries 5 to 10 kilos of fat.
Super powered fuel may be utilized anytime for energy conversion whenever we are in the fat-burning mode.
By harnessing fatty acids for energy, in many ways this propelled organisms with mitochondria to the top of the food chain. Read more about mitochondria in Nick Lane's Power, Sex, Suicide and prior posts HERE.
The birth of PHAT hominid babies with enormous stores of super powered fatty acids produced the evolution of walking, hairless, bigger-brained hominids to the top-tiered creatures that we supposedly are now. Read Stephan Cunnane's Survival of the Fattest and prior posts HERE and HERE.
See prior post: Aerobic Glycolysis (~38 ATP; 6-carbon) v. Aerobic Fat Beta-Oxidation (~146 ATP; 18-carbon)
Mitochondria: Fat Burning Powerhouses + Source of All Chronic Diseases
Without mitochondria derived from bacterial origins of 3.8 billion years ago, animals would not have the ability to efficiently burn the most powerful energy source, fatty acids, and become the most successful predators on the planet.
Not only are mitochondria the nuclear powerhouse of energy, that produce ATP from powerful fats, they are also believed by many who study evolutionary medicine to be the source of all chronic ailments and conditions. Glucose energy is cheap fuel and kills mitochondria when excessive. Many drugs are mitochondrial poisons (e.g. statins). By affecting the thermostat of energy controllers (ratios of NAD/NADP and ADP/ATP) the imbalance affects SIRT-1, AMPK, PPAR and mTOR in a variety of tissues. Depending on the organ, these are known as chronic conditions -- autoimmunity disorders, heart failure, hypertension, adiposity, infertility, cancer, diabetes, et cetera.