Revisi per 10 Februari 2016 08.02 sunting Agung.karjono (bicara \| kontrib) Peninjau, Pengembali revisi 12.047 suntingan →‎Kripton ← Revisi sebelumnya		Revisi per 10 Februari 2016 08.30 sunting balikkan Agung.karjono (bicara \| kontrib) Peninjau, Pengembali revisi 12.047 suntingan →‎Peran biologis Revisi selanjutnya →
Baris 225: == Peran biologis == [[Kalium]] penting bagi kehidupan. Ion kalium dijumpai dalam seluruh sel. Ia diperlukan untuk mempertahankan keseimbangan cairan dan [[elektrolit]]. Sel tanaman sangat kaya kalium, yang mereka dapat dari tanah. Lahan pertanian, yang dipanen setiap tahun, perlu dikembalikan kandungan kaliumnya dengan penambahan [[pupuk]] berbasis kalium. Rata-rata manusia mengkonsumsi sampai dengan 7 gram kalium per hari, dan menyimpan sekitar 140 gram dalam sel tubuh. Diet sehat normal mengandung kalium, tetapi beberapa makanan seperti [[kopi instan]], [[Sarden (makanan)\|sarden]], kacang, [[kismis]], [[kentang]], [[Cokelat\|cokelat]] memiliki kandungan kalium di atas rata-rata. Isotop alami [[kalium-40]] bersifat radioaktif dan, meskipun tingkat radiasinya rendah, merupakan salah satu penyebab alami [[mutasi genetik]] pada manusia.<ref>{{cite web\|url=http://www.rsc.org/periodic-table/element/19/potassium\|title=Potassium\|website=Periodic Table\|publisher=Royal Society of Chemistry\|accessdate=2016-02-10}}</ref> [[Kalsium]] penting bagi seluruh bentuk kehidupan, terutama untuk pertumbuhan dan kesehatan [[tulang]] dan [[gigi]]. [[Kalsium fosfat]] adalah komponen utama tulang. Rata-rata manusia mengandung sekitar 1 kilogram kalsium. Anak-anak dan wanita hamil dianjurkan mengonsumsi makanan yang kaya kalsium, seperti susu dan produk susu, sayuran berdaun hijau, ikan dan kacang serta biji-bijian.<ref>{{cite web\|url=http://www.rsc.org/periodic-table/element/20/calcium\|title=Calcium\|website=Periodic Table\|publisher=Royal Society of Chemistry\|accessdate=2016-02-10}}</ref> <!-- ▼ ~~Potassium is essential to life. Potassium ions are found in all cells. It is important for maintaining fluid and electrolyte balance.~~ Peran biologis [[skandium]] tidak diketahui. Unsur ini diduga [[karsinogen]].<ref>{{cite web\|url=http://www.rsc.org/periodic-table/element/21/scandium\|title=Scandium\|website=Periodic Table\|publisher=Royal Society of Chemistry\|accessdate=2016-02-10}}</ref> Plant cells are particularly rich in potassium, which they get from the soil. Agricultural land, from which harvests are taken every year, needs to have its potassium replenished by adding potassium-based fertilisers. Peran biologis [[titanium]] tidak diketahui. Unsur ini tak beracun. Debu halus [[titanium dioksida]] diduga karsinogen.<ref>{{cite web\|url=http://www.rsc.org/periodic-table/element/22/titanium\|title=Titanium\|website=Periodic Table\|publisher=Royal Society of Chemistry\|accessdate=2016-02-10}}</ref> The average human consumes up to 7 grams of potassium a day, and stores about 140 grams in the body cells. A normal healthy diet contains enough potassium, but some foods such as instant coffee, sardines, nuts, raisins, potatoes and chocolate have above average potassium content. [[Vanadium]] penting bagi beberapa spesies, termasuk manusia, meskipun kebutuhannya sangat kecil. Manusia hanya mengasup sekitar 0,01 miligram per hari, dan ini sudah melebihi kebutuhan harian tubuh manusia. Dalam beberapa senyawa vanadium dapat bersifat racun.<ref>{{cite web\|url=http://www.rsc.org/periodic-table/element/23/vanadium\|title=Vanadium\|website=Periodic Table\|publisher=Royal Society of Chemistry\|accessdate=2016-02-10}}</ref> The naturally occurring isotope potassium-40 is radioactive and, although this radioactivity is mild, it may be one natural cause of genetic mutation in humans. [http://www.rsc.org/periodic-table/element/19/potassium] [[Krom]] atau kromium merupakan unsur renik yang penting bagi manusia karena membantu pemanfaatan [[glukosa]] tubuh. Namun, unsur ini beracun jika berlebih. Asupan harian sekitar 1 miligram per hari. Makanan seperti [[ragi]] bir, ''wheat germ'' dan [[Ginjal\|ginjal]] kaya akan kromium.<ref>{{cite web\|url=http://www.rsc.org/periodic-table/element/24/chromium\|title=Chromium\|website=Periodic Table\|publisher=Royal Society of Chemistry\|accessdate=2016-02-10}}</ref> Calcium is essential to all living things, particularly for the growth of healthy teeth and bones. Calcium phosphate is the main component of bone. The average human contains about 1 kilogram of calcium. Children and pregnant women are encouraged to eat foods rich in calcium, such as milk and dairy products, leafy green vegetables, fish and nuts and seeds. [http://www.rsc.org/periodic-table/element/20/calcium] ~~Scandium has no known biological role. It is a suspected carcinogen. [http://www.rsc.org/periodic-table/element/21/scandium]~~ ~~Titanium has no known biological role. It is non-toxic. Fine titanium dioxide dust is a suspected carcinogen. [http://www.rsc.org/periodic-table/element/22/titanium]~~ Vanadium is essential to some species, including humans, although we need very little. We take in just 0.01 milligrams each day, and this is more than sufficient for our needs. In some compounds vanadium can become toxic. [http://www.rsc.org/periodic-table/element/23/vanadium] Chromium is an essential trace element for humans because it helps us to use glucose. However, it is poisonous in excess. We take in about 1 milligram a day. Foods such as brewer’s yeast, wheat germ and kidney are rich in chromium. [http://www.rsc.org/periodic-table/element/24/chromium] ▲<!-- Manganese is an essential element in all known living organisms. Many types of enzymes contain manganese. For example, the enzyme responsible for converting water molecules to oxygen during photosynthesis contains four atoms of manganese.

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