capturing and converting sources of power
Cells are masters at managing energy, capturing sources of energy from the environment and converting them into forms that the cells can use. Atomic structures have revealed how cells manage chemical energy, mechanical energy, electrical energy, and even light.
Molecule of the Month Articles (29)
|Aconitase and Iron Regulatory Protein 1|
Aconitase performs a reaction in the citric acid cycle, and moonlights as a regulatory protein
Alcohol dehydrogenase detoxifies the ethanol we drink
Amylases digest starch to produce glucose
ATP synthase links two rotary motors to generate ATP
Bacteriorhodopsin pumps protons powered by green sunlight
Beta-galactosidase is a powerful tool for genetic engineering of bacteria
Bacteria build biodegradable plastic that could be better for the environment
Citrate synthase opens and closes around its substrates as part of the citric acid cycle
|Citric Acid Cycle|
Eight enzymes form a cyclic pathway for energy production and biosynthesis
A proton-pumping protein complex performs the first step of the respiratory electron transport chain
A flow of electrons powers proton pumps in cellular respiration and photosynthesis
Cytochrome c shuttles electrons during the production of cellular energy
|Cytochrome c Oxidase|
Cytochrome oxidase extracts energy from food using oxygen
|Fatty Acid Synthase|
Fatty acids are constructed in many sequential steps by a large protein complex
GFP-like proteins found in nature or engineered in the laboratory now span every color of the rainbow
Glycogen phosphorylase releases sugar from its cellular storehouse
The ten enzymes of glycolysis break down sugar in our diet
|Green Fluorescent Protein (GFP)|
A tiny fluorescent protein from jellyfish has revolutionized cell biology
HIF-α is a molecular switch that responds to changing oxygen levels.
Atomic structures have revealed the catalytic steps of a citric acid cycle enzyme
Our cells temporarily build lactate when supplies of oxygen are low
Organisms from fireflies to bacteria use luciferase to emit light
Myoglobin was the first protein to have its atomic structure determined, revealing how it stores oxygen in muscle cells.
Light is captured by huge supercomplexes of photosystems and antenna systems.
Photosystem I captures the energy in sunlight
Phototrophins sense the level of blue light, allowing plants to respond to changing environmental conditions
|Pyruvate Dehydrogenase Complex|
A huge molecular complex links three sequential reactions for energy production
In our eyes, rhodopsin uses the molecule retinal to see light
An activated serine amino acid in trypsin cleaves protein chains
Learning Resources (2)
Structural Biology Highlights (6)
Geis Digital Archive (4)
Geis highlights the hundreds of chemical bonds in the lattice of myoglobin.
Geis illustrated the structure of myoglobin, focusing on the folding pattern of the secondary structure of the protein. Unlike previous myoglobin Illustrations, this painting focuses on the tertiary structure of the molecule rather than the sequence or surface.
Geis illustrates the structure of bovine trypsin, an enzyme that breaks down proteins, which was first revealed by X-ray crystallography in 1971 and further explored in 1974 (Krieger et al., 1974). This illustration was originally published in Scientific American (Stroud, 1984). Trypsin is a protease, an enzyme that catalyzes cleavage of polypeptide chains (Stroud, 1984). Geis' sketch depicts the structure with a ball-and-stick model and displays the sidechains of aspartic acid (Asp102), histidine (His57), and serine (Ser195), known as the catalytic triad.
The colored print depicts the structure of myohemerythrin, which was first revealed by X-ray crystallography in 1975 (Hendrickson et al., 1975) and further refined in 1987 (Sheriff et al., 1987). Geis's illustration depicts the tertiary structure of the protein, highlighting the four anti-parallel alpha-helices and the presence of mu-oxo-diiron (iron atoms in red and oxygen atom in pink) located within the core of the macromolecule (Myohemerythrin).