piątek, 20 października 2017
zamknij [x]
do:

Chemia/Biochemia (847)

1
345... z 43

Zdjęcia

! EN_90272364_0010 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Periodic table, computer artwork with superimposed generic molecular structure. This table shows the chemical elements arranged in order of atomic number (the number of protons in the nucleus). Elements with similar chemistry occur in the same group (vertical column). Some groups are colour-coded: alkali metals (yellow, left, except H); alkaline-earth metals (purple with white text); transition metals (blue, centre); other metals (purple with yellow text, centre right); halogens (dark orange); inert gases (yellow, far right). The lanthanide and actinide series of elements (dark blue with white text) are shown in the lower two rows.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90272364_0011 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Periodic table, computer artwork. This table shows the chemical elements arranged in order of atomic number (the number of protons in the nucleus). Elements with similar chemistry occur in the same group (vertical column). Some groups are colour-coded: alkali metals (yellow, left, except H); alkaline-earth metals (purple with white text); transition metals (blue, centre); other metals (purple with yellow text, centre right); halogens (dark orange); inert gases (yellow, far right). The lanthanide and actinide series of elements (dark blue with white text) are shown in the lower two rows.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90272364_0012 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Periodic table, computer artwork. This table shows the chemical elements arranged in order of atomic number (the number of protons in the nucleus). Elements with similar chemistry occur in the same group (vertical column). Some groups are colour-coded: alkali metals (yellow, left, except H); alkaline-earth metals (purple with white text); transition metals (blue, centre); other metals (purple with yellow text, centre right); halogens (dark orange); inert gases (yellow, far right). The lanthanide and actinide series of elements (dark blue with white text) are shown in the lower two rows.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90248314_0003 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Bisphenol A, molecular model. This chemical is used in the plastics industry as an antioxidant and as a component of epoxy resins and polycarbonate plastics. There are concerns that increasing levels of bisphenol A in the environment could be harmful. It is already known as a synthetic oestrogen that lowers sperm count in men and is also thought to disrupt foetal development. Atoms are represented as spheres are colour-coded: carbon (black), oxygen (red) and hydrogen (grey).
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90248314_0004 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Bisphenol A, molecular model. This chemical is used in the plastics industry as an antioxidant and as a component of epoxy resins and polycarbonate plastics. There are concerns that increasing levels of bisphenol A in the environment could be harmful. It is already known as a synthetic oestrogen that lowers sperm count in men and is also thought to disrupt foetal development. Atoms are represented as spheres are colour-coded: carbon (blue), oxygen (red) and hydrogen (yellow).
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90248314_0005 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Bisphenol A, molecular model. This chemical is used in the plastics industry as an antioxidant and as a component of epoxy resins and polycarbonate plastics. There are concerns that increasing levels of bisphenol A in the environment could be harmful. It is already known as a synthetic oestrogen that lowers sperm count in men and is also thought to disrupt foetal development. Atoms are represented as spheres are colour-coded: carbon (blue), oxygen (red) and hydrogen (yellow).
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90268567_0001 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Miller-Urey experiment. Artwork of the apparatus used in the Miller-Urey experiment to study the origin of life. This 1950s experiment attempted to duplicate the conditions which would have existed on the primordial Earth. The apparatus contains a 'sea' of sterile water (bottom) and an 'atmosphere' of hydrogen, methane and ammonia (top right). Electrodes give off a spark (right) to imitate either lightning or ultra-violet radiation from the Sun. The result is a tar-like residue containing amino acids, the basic building blocks of life.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90274300_0003 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Prostacyclin molecule. Computer model showing the structure of the hormone prostacyclin, or prostaglandin I2 (PGI2). Atoms are colour-coded (carbon: dark grey, hydrogen: light grey, oxygen: red). Prostacyclin acts to widen blood vessels (thus lowering blood pressure) and to prevent aggregation of platelets (preventing blood clotting). These effects are the opposite of those of the related hormone thromboxane, and the balance between the two is important in regulating the functioning of the circulatory system. When taken as a drug it is known as epoprostenol.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90274300_0004 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Prostacyclin molecule. Computer model showing the structure of the hormone prostacyclin, or prostaglandin I2 (PGI2). Atoms are colour-coded (carbon: dark grey, hydrogen: light grey, oxygen: red). Prostacyclin acts to widen blood vessels (thus lowering blood pressure) and to prevent aggregation of platelets (preventing blood clotting). These effects are the opposite of those of the related hormone thromboxane, and the balance between the two is important in regulating the functioning of the circulatory system. When taken as a drug it is known as epoprostenol.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90274302_0001 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Prostaglandin E1 molecule. Computer model showing the structure of the hormone prostaglandin E1 (PGE1). Atoms are colour-coded (carbon: dark grey, hydrogen: light grey, oxygen: red). PGE1 acts to widen blood vessels (vasodilation), thus lowering blood pressure and improving blood flow. It is therefore used as a drug, known as Alprostadil, to treat erectile dysfunction.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90274302_0002 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Prostaglandin E1 molecule. Computer model showing the structure of the hormone prostaglandin E1 (PGE1). Atoms are colour-coded (carbon: dark grey, hydrogen: light grey, oxygen: red). PGE1 acts to widen blood vessels (vasodilation), thus lowering blood pressure and improving blood flow. It is therefore used as a drug, known as Alprostadil, to treat erectile dysfunction.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90274303_0001 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Prostaglandin E2 molecule. Computer model showing the structure of the hormone prostaglandin E2 (PGE2). Atoms are colour-coded (carbon: dark grey, hydrogen: light grey, oxygen: red). Like other prostaglandins PGE2 acts to widen blood vessels (vasodilation), thus lowering blood pressure and improving blood flow. It also relaxes smooth muscles and inhibits the release of noradrenaline. It softens the cervix and causes uterine contraction during labour, and is therefore used as a vaginal suppository (dinoprostone) to prepare the cervix for labour and also to induce labour.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90274303_0002 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Prostaglandin E2 molecule. Computer model showing the structure of the hormone prostaglandin E2 (PGE2). Atoms are colour-coded (carbon: dark grey, hydrogen: light grey, oxygen: red). Like other prostaglandins PGE2 acts to widen blood vessels (vasodilation), thus lowering blood pressure and improving blood flow. It also relaxes smooth muscles and inhibits the release of noradrenaline. It softens the cervix and causes uterine contraction during labour, and is therefore used as a vaginal suppository (dinoprostone) to prepare the cervix for labour and also to induce labour.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90274304_0001 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Prostaglandin F2a molecule. Computer model showing the structure of the hormone prostaglandin F2a (PGF2a). Atoms are colour-coded (carbon: dark grey, hydrogen: light grey, oxygen: red). Like other prostaglandins PGF2a acts to widen blood vessels (vasodilation), thus lowering blood pressure and improving blood flow. It is produced by the uterus, where it triggers the breakdown of the corpus luteum (luteolysis) if no embryo has been implanted, and stops the production of progesterone. It is therefore marketed as a drug used to induce abortion (an abortifacient) when it is known as Dinoprost.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90274304_0002 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Prostaglandin F2a molecule. Computer model showing the structure of the hormone prostaglandin F2a (PGF2a). Atoms are colour-coded (carbon: dark grey, hydrogen: light grey, oxygen: red). Like other prostaglandins PGF2a acts to widen blood vessels (vasodilation), thus lowering blood pressure and improving blood flow. It is produced by the uterus, where it triggers the breakdown of the corpus luteum (luteolysis) if no embryo has been implanted, and stops the production of progesterone. It is therefore marketed as a drug used to induce abortion (an abortifacient) when it is known as Dinoprost.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90277132_0001 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Salmon calcitonin hormone molecule. Computer model showing the structure of calcitonin from salmon. Atoms are colour-coded spheres (carbon: dark grey, hydrogen: light grey, nitrogen: blue, sulphur: yellow, and oxygen: red). Calcitonin is a linear polypeptide that is produced primarily by parafollicular cells (C-cells) in the thyroid gland. It acts to reduce blood calcium levels by opposing the effects of parathyroid hormone (PTH). Salmon calcitonin is used to treat a number of disorders in humans, including postmenopausal osteoporosis, and hypercalcaemia (high calcium blood levels). It is used as it is rapidly absorbed and eliminated from the body and is therfore safer than the human form.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90277132_0002 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Salmon calcitonin hormone molecule. Computer model showing the structure of calcitonin from salmon. Atoms are colour-coded spheres (carbon: dark grey, hydrogen: light grey, nitrogen: blue, sulphur: yellow, and oxygen: red). Calcitonin is a linear polypeptide that is produced primarily by parafollicular cells (C-cells) in the thyroid gland. It acts to reduce blood calcium levels by opposing the effects of parathyroid hormone (PTH). Salmon calcitonin is used to treat a number of disorders in humans, including postmenopausal osteoporosis, and hypercalcaemia (high calcium blood levels). It is used as it is rapidly absorbed and eliminated from the body and is therfore safer than the human form.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90278065_0001 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Secretin hormone molecule. Computer model showing the structure of the hormone secretin. Atoms are colour-coded (carbon: dark grey, hydrogen: light grey, oxygen: red). Secretin controls the secretions into the upper part of the small intestine (duodenum), and also water homeostasis throughout the body. It is produced in the S cells of the duodenum and regulates the acidity of the duodenal contents through the control of gastric acid secretion and buffering (neutralising) with bicarbonate.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90278065_0002 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Secretin hormone molecule. Computer model showing the structure of the hormone secretin. Atoms are colour-coded (carbon: dark grey, hydrogen: light grey, oxygen: red). Secretin controls the secretions into the upper part of the small intestine (duodenum), and also water homeostasis throughout the body. It is produced in the S cells of the duodenum and regulates the acidity of the duodenal contents through the control of gastric acid secretion and buffering (neutralising) with bicarbonate.
Wysoka rozdzielczosc dostepna na zamowienie
! EN_90278326_0004 SCI
PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Serotonin molecule. Computer model showing the structure of the neurotransmitter (nerve signalling chemical) serotonin (5-hydroxytryptamine). Atoms are colour-coded (carbon: dark grey, hydrogen: light grey, nitrogen: blue, and oxygen: red). Serotonin is an important brain signalling molecule and a lack of it has been shown to cause depression and other mood disorders.
Wysoka rozdzielczosc dostepna na zamowienie

góra

1
345... z 43