Name: suspensions, sedimentation, and colloids
Uploaded: 2023-06-23T15:38:43.000Z
Duration: 1 min 17 s
Channel: JoVE

Kolloidler ve süspansiyonlar, fiziksel olarak birbirine karışmış iki veya daha fazla bileşenin heterojen karışımlarıdır.
Bir kolloidde, çözünen parçacıkların boyutu 1 ila 1000 nanometre arasında değişir, tek tek görünmez olacak kadar küçüktür. Bununla birlikte, bu çözünen parçacıklar ışığı dağıtarak kolloidlerin yarı saydam veya opak görünmesine neden olabilir. Süresiz olarak çözümde kalırlar ve yerleşmezler.
Canlı hücrelerin içindeki yarı akışkan materyal olan sitozol, içinde dağılmış çok sayıda protein ve metabolit nedeniyle bir kolloiddir.
Buna karşılık, süspansiyonlar, genellikle çıplak gözle görülebilen, genellikle 10000 nanometrenin üzerinde büyük parçacıklar içerir.
Rahatsız edilmeden bırakıldığında, bu parçacıklar tortular halinde çöker.
Kan, askıya almaya bir örnektir. Taze çekilmiş kan bir süre rahatsız edilmeden bırakıldığında, kırmızı kan hücreleri kabın dibine yerleşir. Kan plazması olarak adlandırılan üst sıvı kısım, küçük çözünen maddelerin yanı sıra daha büyük plazma proteinleri içeren bir kolloidin bir çözeltisidir.

kolloidler ve sürspansiyonlar

Oyun oynayan çocuklar sık sık çamur ve su, un ve su, veya su ile karıştırılan katı pigmentlerin sürspansiyonu olan tempera boyası gibi karışımlar yaparlar. Bu sürspansiyonlar, çıplak gözle veya büyüteçle görülebilen göreceli büyük parçacıklardan oluşan heterojen karışımlardır. Bulanık ve karıştıktan sonra askıdaki partiküller çöker. Bir sürspansiyondaki askıdaki partiküller, karıştırmadan bir süre sonra çöker. Bir sürspansiyondan partiküllerin ayrılması çökme olarak adlandırılır. Çökme oranını belirlemek için yapılan bir kan testi, bir test tüpünde kırmızı kan hücrelerinin su kısmından (plazma olarak bilinir) belirli bir süre içinde ne kadar hızlı çöktüğünü ölçer. Kırmızı kan hücrelerinin hızlı bir şekilde çökmesi genellikle sağlıklı bir vücutta gerçekleşmez. Bununla birlikte, bazı hastalıkların belirli yönleri kan hücrelerinin bir araya yapışmasına neden olabilir ve bu ağır kan hücreleri normal kan hücrelerinden daha hızlı bir şekilde test tüpünün dibine çöker.

Süspansiyonlar ve çözeltiler arasında özellikleri arasıda kalan bir karışım sınıfı olan kolloidler (veya kolloidal dağılımlar) vardır. Bir kolloiddeki partiküller çoğu basit moleküllerden daha büyüktür; ancak, kolloidal partiküller yüksüz durmada çökelmez. Bir kolloiddaki partiküller, ışığı saçabilir boyuttadır; bu olaya Tyndall etkisi denir; bu yüzden kolloidal karışımlar bulanık veya opak görünürler, örneğin arama ışığı ışınları gibi. Bulutlar da kolloidal karışımlardır. Su damlacıklarından oluşurlar, bu damlacıklar moleküllerden çok daha büyüktür ancak çökelmezler. Bazı kolloidler, tersinir şekilde akışkan bir durumdan katı bir duruma (jel) dönüşebilen sol-jel dönüşümlerini gerçekleştirme özelliğine sahiptir. Örneğin, jelatin ürünleri soğutulduğunda jel oluşturarak katılaşırlar, tekrar ısıtıldığında ise sıvılaşabilirler. Canlı hücrelerin sıvısı olan sitozolün sol-jel özelliği, hücre bölünmesi veya hücre şeklinde değişim gibi birçok hücresel faaliyet için önemlidir. Bir kolloidal çözümün parçacık bileşeni, görece küçük bir miktarda bulunan askı durumudaki bileşendir. Parçacıkların dağıldığı madde veya çözelti, dağılım ortamı olarak adlandırılır.

Bu metin <a href="https://openstax.org/books/anatomy-and-physiology-2e/pages/2-4-inorganic-compounds-essential-to-human-functioning">Openstax, Anatomy and Physiology 2e, Section 2.4: Inorganic Compounds Essential to Human Functioning</a> and <a href="https://openstax.org/books/chemistry-2e/pages/11-5-colloids">Openstax, Chemistry 2e, Section 11.5: Colloids</a>.

Kolloidler ve Sürspansiyonlar

Oyun oynayan çocuklar genellikle çamur ve su, un ve su karışımları veya suda tempera olarak bilinen katı pigmentlerin bir süspansiyonu gibi süspansiyonlar yaparlar ...

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Anatomy and Physiology

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Unit 1

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Fundamentals of Chemistry

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KEY TERMS AND CONCEPTS

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Colloids and Suspensions

suspensions, sedimentation, and colloids

Suspensions and colloids are two common kinds of mixtures seen in everyday life. Mud and water, flour and water, and tempera paint are suspensions. These mixtures are heterogeneous, which means their particles are not spread out evenly. The particles are relatively large and can be seen with the naked eye or a magnifying glass.

Suspension particles make mixtures cloudy, and they settle out after mixing. The settling of particles in a suspension is called sedimentation. A blood test can measure the rate of sedimentation by showing how fast red blood cells settle out of plasma, the watery part of blood, in a test tube over time. Rapid sedimentation is not usual in a healthy body, but some diseases can cause blood cells to clump together and sink faster than normal cells.

Colloids, also called colloidal dispersions, sit between suspensions and solutions. Their particles are larger than most simple molecules, but they are small enough that they do not settle out when left standing. Colloidal particles are still large enough to scatter light. This is known as the Tyndall effect, and it makes colloids look cloudy or opaque, like a beam from a searchlight.

Clouds are another example of a colloid. They contain water droplets that are bigger than molecules, but still small enough to stay suspended in the air. Some colloids can also change from a fluid sol to a solid gel and back again. Gelatin is one example. It forms a gel when chilled and can become liquid again when heated. The sol-gel behavior of cytosol, the fluid inside living cells, is important for cell division and for changes in cell shape.

In a colloid, the dispersed phase is the particulate part present in smaller amount. The dispersion medium is the substance that carries the particles throughout the mixture. These terms help describe how colloids are organized and why they behave differently from suspensions and solutions.

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anatomy and physiology

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Suspensions, Sedimentation, and Colloids

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