{"id":971,"date":"2017-10-26T17:17:09","date_gmt":"2017-10-26T17:17:09","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/sunynutrition\/?post_type=chapter&p=971"},"modified":"2017-11-14T17:17:31","modified_gmt":"2017-11-14T17:17:31","slug":"12-23-calcium-functions","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/atd-herkimer-nutrition\/chapter\/12-23-calcium-functions\/","title":{"raw":"12.23 Calcium Functions","rendered":"12.23 Calcium Functions"},"content":{"raw":"
\r\n\r\nCalcium in hydroxyapatite is a major component of bones and teeth.\r\n\r\nThere are also a number of non-bone functions of calcium. Calcium is an intracellular signaling molecule. Because of this, intracellular calcium is tightly controlled, primarily stored within organelles.\r\n\r\nNon-bone functions include:\r\n\r\nNeurotransmitter release<\/b>\r\n\r\nNeurotransmitter release is stimulated by the opening of voltage-gated Ca2+ channels. This stimulates the synaptic vesicle to fuse with the axon membrane and release the neurotransmitter into the synapse, as shown below1<\/sup>.\r\n
\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"800\"]\"\" Figure 12.231 Calcium regulates neurotransmitter release2<\/sup>[\/caption]\r\n\r\n<\/div>\r\nMuscle contraction<\/b>\r\n\r\nCalcium is released in muscle cells, where it binds to the protein troponin, changes its shape, and removes the tropomyosin blockade of actin active sites so that contraction can occur3<\/sup>. This can be seen in the following animation and figure (same link).\r\n<\/colgroup>\r\n\r\n\r\n
Web Link<\/b>\r\n\r\nMuscle <\/u><\/a>contraction<\/u><\/a><\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\nHormone release<\/b>\r\n\r\nCalcium acts as an intracellular messenger for the release of hormones, such as insulin. The link below shows how in the beta cells of the pancreas, the opening of voltage-gated calcium channels stimulates the insulin granules to fuse with the beta cell membrane to release insulin.\r\n<\/colgroup>\r\n\r\n\r\n
Web Link<\/b>\r\n\r\nInsulin release<\/u><\/a><\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\nBlood Clotting<\/b>\r\n\r\nAs will be discussed more in the vitamin K section, calcium binding to activated Gla proteins is important in the blood clotting cascade.\r\n
\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"840\"]\"\" Figure 12.232 Calcium bind to Gla proteins. Adapted from reference 4<\/sup>[\/caption]\r\n\r\n<\/div>\r\nEnzyme regulation<\/b>\r\n\r\nThe binding of calcium to calcium-binding proteins also regulates the action of a number of enzymes4<\/sup>.\r\n\r\nReferences & Links<\/b>\r\n\r\n1. Byrd-Bredbenner C, Moe G, Beshgetoor D, Berning J. (2009) Wardlaw's perspectives in nutrition. New York, NY: McGraw-Hill.\r\n\r\n2. http:\/\/en.wikipedia.org\/wiki\/File:Synapse_Illustration_unlabeled.svg\r\n\r\n3.http:\/\/legacy.owensboro.kctcs.edu\/GCaplan\/anat\/Notes\/API%20Notes%20J%20%20Muscle%20Contraction.htm\r\n\r\n4. Gropper SS, Smith JL, Groff JL. (2008) Advanced nutrition and human metabolism. Belmont, CA: Wadsworth Publishing.\r\n\r\nLinks<\/b>\r\n\r\nMuscle contraction - http:\/\/legacy.owensboro.kctcs.edu\/GCaplan\/anat\/Notes\/API%20Notes%20J%20%20Muscle%20Contraction.htm\r\n\r\nInsulin release - http:\/\/www.dolcera.com\/wiki\/images\/Image11.jpeg\r\n\r\n<\/div>","rendered":"
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Calcium in hydroxyapatite is a major component of bones and teeth.<\/p>\n

There are also a number of non-bone functions of calcium. Calcium is an intracellular signaling molecule. Because of this, intracellular calcium is tightly controlled, primarily stored within organelles.<\/p>\n

Non-bone functions include:<\/p>\n

Neurotransmitter release<\/b><\/p>\n

Neurotransmitter release is stimulated by the opening of voltage-gated Ca2+ channels. This stimulates the synaptic vesicle to fuse with the axon membrane and release the neurotransmitter into the synapse, as shown below1<\/sup>.<\/p>\n

\n
\"\"<\/p>\n

Figure 12.231 Calcium regulates neurotransmitter release2<\/sup><\/p>\n<\/div>\n<\/div>\n

Muscle contraction<\/b><\/p>\n

Calcium is released in muscle cells, where it binds to the protein troponin, changes its shape, and removes the tropomyosin blockade of actin active sites so that contraction can occur3<\/sup>. This can be seen in the following animation and figure (same link).<\/p>\n\n\n<\/colgroup>\n\n\n
Web Link<\/b><\/p>\n

Muscle <\/u><\/a>contraction<\/u><\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Hormone release<\/b><\/p>\n

Calcium acts as an intracellular messenger for the release of hormones, such as insulin. The link below shows how in the beta cells of the pancreas, the opening of voltage-gated calcium channels stimulates the insulin granules to fuse with the beta cell membrane to release insulin.<\/p>\n\n\n<\/colgroup>\n\n\n
Web Link<\/b><\/p>\n

Insulin release<\/u><\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Blood Clotting<\/b><\/p>\n

As will be discussed more in the vitamin K section, calcium binding to activated Gla proteins is important in the blood clotting cascade.<\/p>\n

\n
\"\"<\/p>\n

Figure 12.232 Calcium bind to Gla proteins. Adapted from reference 4<\/sup><\/p>\n<\/div>\n<\/div>\n

Enzyme regulation<\/b><\/p>\n

The binding of calcium to calcium-binding proteins also regulates the action of a number of enzymes4<\/sup>.<\/p>\n

References & Links<\/b><\/p>\n

1. Byrd-Bredbenner C, Moe G, Beshgetoor D, Berning J. (2009) Wardlaw’s perspectives in nutrition. New York, NY: McGraw-Hill.<\/p>\n

2. http:\/\/en.wikipedia.org\/wiki\/File:Synapse_Illustration_unlabeled.svg<\/p>\n

3.http:\/\/legacy.owensboro.kctcs.edu\/GCaplan\/anat\/Notes\/API%20Notes%20J%20%20Muscle%20Contraction.htm<\/p>\n

4. Gropper SS, Smith JL, Groff JL. (2008) Advanced nutrition and human metabolism. Belmont, CA: Wadsworth Publishing.<\/p>\n

Links<\/b><\/p>\n

Muscle contraction – http:\/\/legacy.owensboro.kctcs.edu\/GCaplan\/anat\/Notes\/API%20Notes%20J%20%20Muscle%20Contraction.htm<\/p>\n

Insulin release – http:\/\/www.dolcera.com\/wiki\/images\/Image11.jpeg<\/p>\n<\/div>\n\n\t\t\t

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Candela Citations<\/h3>\n\t\t\t\t\t
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