On the verge…
Emerge
I synthesize
[Instrumental, Sub-bass, Synthesizers]
[Verse 1]
With just the right light
Longer before night
Soar to new heights
(We just might)
[Bridge]
Grow into the flow
[Chorus]
Nourishment (meant)
Enrichment (meant)
Environment (meant)
[Instrumental, Guitar Solo, Drum Fills]
[Verse 2]
Synthesize sunlight
Soar to new heights
(We just might)
[Bridge]
Grow into the flow
[Chorus]
Nourishment (meant)
Enrichment (meant)
Environment (meant)
[Instrumental, Saxophone Solo, Drum Fills]
[Break]
Environment (meant)
[Bridge]
Roots are down to Earth
Gave way to my birth
Through time I go
The seeds I sow
Grow into the flow
[Chorus]
Nourishment (meant)
Enrichment (meant)
Environment (meant)
[Instrumental, Piano Solo, Bass]
[Outro]
Environment (meant)
A SCIENCE NOTE
Plants
Plants do not synthesize light; instead, they utilize a process called photosynthesis to capture and convert light energy from the sun into chemical energy. Photosynthesis occurs primarily in chloroplasts, specialized organelles found in plant cells, particularly in the leaves.
The process of photosynthesis involves several steps:
- Light Absorption: Chlorophyll, the green pigment found in chloroplasts, absorbs light energy from the sun. Other pigments, such as carotenoids, also contribute to light absorption, particularly in capturing different wavelengths of light.
- Water Splitting (Photolysis): The absorbed light energy is used to split water molecules (H2O) into oxygen (O2), protons (H+), and electrons (e^-). This process occurs in the thylakoid membranes of the chloroplasts.
- Electron Transport Chain: The excited electrons produced during photolysis are transferred through a series of protein complexes embedded in the thylakoid membranes. This movement of electrons generates a proton gradient across the membrane, creating a source of potential energy.
- ATP and NADPH Formation: The energy from the electron transport chain is used to phosphorylate adenosine diphosphate (ADP) to form adenosine triphosphate (ATP) and to reduce nicotinamide adenine dinucleotide phosphate (NADP+) to form NADPH. These molecules serve as energy carriers for the subsequent reactions in photosynthesis.
- Carbon Fixation (Calvin Cycle): The ATP and NADPH generated during the light-dependent reactions are used to drive the Calvin cycle, also known as the dark reactions or light-independent reactions. In this cycle, carbon dioxide (CO2) from the atmosphere is converted into organic molecules, such as glucose, through a series of enzyme-catalyzed reactions. This process occurs in the stroma of the chloroplasts and utilizes the ATP and NADPH produced during the light-dependent reactions.
Photosynthesis allows plants to harness solar energy to produce carbohydrates, which serve as energy sources for growth, metabolism, and reproduction. In addition to producing oxygen as a byproduct, photosynthesis plays a crucial role in maintaining the balance of atmospheric gases and supporting ecosystems worldwide.
Humans
Humans do not photosynthesize sunlight to directly produce vitamin D in the same way that plants use photosynthesis to synthesize carbohydrates. Instead, humans rely on a process that occurs in their skin in response to sunlight exposure.
When the skin is exposed to ultraviolet B (UVB) radiation from sunlight, a precursor molecule called 7-dehydrocholesterol, which is naturally present in the skin, undergoes a chemical reaction. This reaction converts 7-dehydrocholesterol into previtamin D3, which is then rapidly converted into vitamin D3 (cholecalciferol) through a heat-dependent process.
Vitamin D3 is not yet active and needs further processing to become biologically active. The liver plays a crucial role in this process by hydroxylating vitamin D3 to form 25-hydroxyvitamin D [25(OH)D], also known as calcidiol. This compound serves as the major circulating form of vitamin D in the bloodstream and is used as a measure of vitamin D status in the body.
Finally, 25(OH)D undergoes additional hydroxylation in the kidneys, primarily, to form the biologically active form of vitamin D, known as 1,25-dihydroxyvitamin D [1,25(OH)2D] or calcitriol. Calcitriol regulates calcium and phosphate metabolism, promoting bone health and supporting various physiological functions throughout the body.
Sunlight exposure plays a crucial role in initiating the synthesis of vitamin D in the skin, which is then further processed in the liver and kidneys to produce the biologically active form of the vitamin. However, it’s important to balance sun exposure to avoid harmful effects of excessive UV radiation, such as sunburn and an increased risk of skin cancer.