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DNA methylation is the main epigenetic modfication of DNA. Methylation can change the activity of a DNA segment. The DNA methyl transferase I (light blue) transfers a methyl group from S-adenosyl methionine  (red) mostly to cytosine bases of the human DNA. Source: PDB entry 3pt6
A ball and stick + ribbons model of HIV protease - an enzyme that is the target of much AIDS and HIV research.
3D cartoon and Gaussian surface models, PDB 6vg8, white background
Artificial molecular structure in many colors. Horizontal composition, isolated on white background.
c-Myc and Max transcription factors bound to DNA. 3D illustration. Atoms shown as spheres with conventional color coding.
DNA A-T Pair
Cholera toxin, molecular model. Cholera toxin (choleragen) is a protein complex secreted by the bacterium Vibrio cholerae, that causes the disease cholera. It is made up of a wedge-shaped A subunit (right part of illustration) and five B subunits (left part of illustration) that form a ring which binds to the intestinal lining. In its most severe forms, cholera is one of the most rapidly fatal illnesses known.
Abstract geometric shape
Avibactam is a diazobicyclooctane inhibitor of gram-negative and gram-positive bacteria.  Avibactam (red) inhibits the bacterial enzyme beta-lactamase (blue) of Clostridioides difficile.
A ball-and-stick molecular model of the hormone Orexin, also known as Hypocretin.  Orexin is involved in the regulation of the sleep/wake cycle and it stimulates apetite, wakefulness and energy expenditure. It has been linked with Alzheimer's disease.  Isolated on white.
3D cartoon and Gaussian surface models. PDB 3kqg, chain id color scheme, white background.
DNA molecules
Glucose-6-phosphate dehydrogenase (G6PD) protein. Enzyme of the pentose phosphate pathway that generates co-enzyme NADPH. 3D illustration.
Molecular model of Thymine, 1 of 4 nucleobases to form DNA
Abstract Pink And Green Knot
Abstract geometric shape
PETase (left) degrades  polyethylene terephtalate (PET) into monohydroxyethyl terephthalate (MHET) and MHETase degrades MHET ethylene glycol (EG) and terephthalic acid (TPA).
A model of a molecule of arginine, an amino acid. Amino acids are the building blocks of proteins and have many functions in metabolism. In particular, Arginine has an important function in the immune system, wound healing and cell division.
3D cartoon and Gaussian surface models, PDB 7s03, white background
Liquid bubbles up Fluid Twirl
Indoleamine 2,3 dioxygenase 1 (IDO1) protein. Tryptophan catabolic enzyme of the kynurenine pathway. 3D illustration.
Model of human Insulin, a hormone to regulate carbohydrate and fat metabolism
Remdesivir is a broad-spectrum antiviral medication, it is a specific treatment for COVID-19. 3d illustration
Scientific background. 3D render.
Organic shape 3d virus model isolated on black background, medical 3d rendering illustration
A space-filling molecular model of collagen, a fibrous protein that provides structural support in animals. It has a distinctive triple helix structure. Isolated on black.
3D cartoon and Gaussian surface models, PDB 1j7n, chain id color scheme, white background
broken metalic DNA model.
Interleukin 13 (IL-13) cytokine protein. 3D illustration. Atoms shown as spheres with conventional color coding.
Molecular model of Adenosine triphosphate,  or Adenosine-5'-triphosphate (ATP)
Free Images: "bestof:PDB 1zqf EBI.jpg All alpha proteins SAM domain-like DNA polymerase beta N-terminal domain-like DNA polymerase beta N-terminal domain-like DNA polymerase beta"
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Lasioglossum_taylorae,_F,_Back,_MA,_Franklin_County_2015-07-07-11.55.17_ZS_PMax_UDR.jpg
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Svastra_obliqua,_m,_back,_Dorchester_Co_2015-12-03-11.21.jpg
Coelioxys_alternata,_F,_Side,_Virginia,_Franklin_County_2014-12-05-16.17.57_ZS_PMax.jpg
China_Bee_1,_U,_Side_2015-08-10-09.58.58_ZS_PMax_UDR.jpg
Ctenocolletes_smaragdinus,_f,_australia,_side_2014-08-08-13.53.31_ZS_PMax.jpg
Lasioglossum_lilliputense,_F,_Face,_WY,_Teton_County_2015-06-08-15.30.48_ZS_PMax.jpg
Hylaeus_verticalis,_M,_side,_Michigan,_Keweenaw_County_2014-11-25-10.56.jpg
(beetle),_Back,_Judelot_Farm,_Maryland_2014-10-20-14.30.jpg
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bee_species,_f,_side,_argentina_2014-08-07-15.38.54_ZS_PMax.jpg
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centepede_2015-04-16-09.57.17_ZS_PMax.jpg
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Andrena_hirticincta_,_f,_face,_Maine,_Du_Clos_2015-12-01-11.24.jpg
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Stelis_louisae,_M,_Back1,_MD,_Dorchester_County_2015-09-22-13.00.30_ZS_PMax_UDR.jpg
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