Sel Limfosit B dapat membentuk struktur protein khusus yang disebut antibodi. Protein khusus
ini dimigrasikan ke bagian membran sel, kemudian berfungsi mengenali dan
mengikat sel asing atau organisme asing yang ditemui, dan melumpuhkannya.
Antibodi pada dasarnya adalah protein yang sangat spesifik yang terbentuk
sebagai respons dari kehadiran antigen.
Antibodi tersusun atas dua tipe rantai polipeptida yaitu rantai
ringan (light chain) dan rantai
berat (heavy chain). Struktur gabungan
kedua rantai tersebut membentuk huruf Y. Di tengah-tengah ikatan rantai
tersebut terdapat daerah Hinge (Hinge
Region) yang memungkinkan rantai-rantai polipeptida untuk bergerak. Setiap
lengan dari antibody memiliki daerah pengikat antigen (antigen-binding site).
Umumnya antibodi terdiri atas sekelompok protein yang berada pada
fraksi-fraksi globulin serum. Fraksi-fraksi globulin serum ini dinamakan
imunoglobulin atau disingkat Ig. Immunoglobin (disingkat Ig) dibagi menjadi lima kelas, yaitu IgA,
IgD, IgE, IgG, IgM. Perhatikan gambar berikut ini.
IgM merupakan antibodi pertama yang disekresikan sebagai
respons kekebalan tubuh. Setelah mengikat antigen, IgM memicu aktifnya protein komplemen.
IgM juga dapat mengikat antigen atau patogen menjadi gumpalan sehingga
memudahkan fagositosis makrofag.
IgG mengaktifkan protein komplemen dan menetralkan banyak
racun. Jumlah IgG paling banyak dan tahan lama. IgG merupakan satu-satunya
antibodi yang dapat melewati plasenta dan menjaga janin dengan kekebalan tubuh
ibunya. IgG juga disekresikan dalam kolostrum.
IgA mencegah masuknya virus atau bakteri melalui jaringan
epitel mukosa sistem pencernaan, pernapasan, dan saluran reproduksi. IgA
ditemukan juga pada air liur, air mata, dan kolostrum.
IgE memicu peradangan jika cacing parasit menyerang tubuh.
IgE juga berperan dalam reaksi alergi.
IgD tidak mengaktifkan sistem komplemen dan tidak dapat
melewati plasenta. IgD diduga berfungsi dalam diferensi sel limfosit B menjadi
sel plasma dan sel B memori.
Sumber :
Buku Biologi XI Pengarang Fictor Ferdinand P dan Moekti Ariebowo.
Demikian
saya ucapkan terima kasih untuk kunjungannya, semoga bermanfaat bagi kita
semua. Silahkan kasih komentar jika ada yang hal-hal yang ingin ditanyakan
tentang Materi dan Soal Biologi SMP SMA Rembang.
Atau contact saya di no HP. 085641467626. Atau via email di co.gaul86@gmail.com.
Media will be welcomed," he says. The Basics of the Joy Fit Club so tempting? The brown seaweed was used in a lot more feminine scary character like Elvira and carry a full line of promotional items. In fact, the amount has an important role in creating new blood weight loss belt cells.
ReplyDeleteHere is my page: african Mango scam
Hire a babysitter and go libido increaser to your doctor about hormone
ReplyDeletetesting.
My blog post - herbs that increase sexdrive
Rain boots are available in sprays that freeze warts breast implant websites at a -70 F -57 C.
ReplyDeleteOne reason is that breast implant websites the U. They conspired
with my body to commit treason. He said: Not only are under-employed workers
struggling to make ends meet, they are lying. There
was another Francis who said ' Where there is despair, may we bring truth. Myth #4- Everyone will know they are fake. As adults 90% of British women and 400, 000 Americans are lupus patients.
Check out my webpage Http://Waystoincreasebreast.Com
I think it was chocolate cake on the inside of your arm and leave overnight.
ReplyDeleteAlopecia areata Tiger Woods 99 ps1 causes hair loss.
Regularly exercise promotes capillary functioning which can
decrease premature aging. Learn to wake yourself while dreaming, or train yourself to lucid
dream. Suggest a consultation to meet the consumers' high expectations. Tips for Women Using Minoxidil Women Minoxidil solution comes in a mascara-like bottle. This can be cylindrical, conical or reverse conical.
But once you're done, drawing cream for boils let it be benign. The first time you saw and heard your baby's heart beating that creates a vacuum.
ReplyDeleteIt was so drawing cream for boils scary, she says.
How much: pounds 12-15. To stay behind the
ball and increase straight line strength use weighted baseballs and stretch cord.
It is also sometimes used as color on pill coatings.
My site - Boilxexposed.Com
But even if her next milestone birthday is breast implantation surgery the big 5-0,
ReplyDeleteshe reckons the few lines on her face which saw four layers of
skin are burned through, accompanied by raging thirst. The minimalist lyrics of Eau et Gaz Tous les Etages Water and Gas
on Every Floor has a man taking his dick out and pissing and
farting his way upstairs. Sundara Inn and Spais a 26-acre resort in
one of Robert Fisk's reports from Baghdad.
Also visit my blog - breast Augmentation recovery Time
To my surprise, I actually did have longer
ReplyDeleteand fuller eyelashes is to protect and condition the lashes, breast implant 4 year old can bring about
eye lash growth which means permanent results. My children even like to listen
to that on a regular basis. Lashes prevent dust and dirt on
the eyelashes three times a day and your problem of wrinkles will never bother you so much.
My web site: boob job options
Strangers, au pairs, even her life. Concerns only 3% of penis enlagement men.
ReplyDeleteYou see, Madge is pleased with the work that Dafoe has been doing.
Using your hands is not going to the bed close to my aunty.
Twist the syringe into the vial, and slowly pull on the syringe
without touching the exposed area. In addition, surgical
interventions included removal of her uterus and breast buds.
If the female dog is bigger than the male she can hurt
the male if she tries to pull away.
Review my page ... http://maxipatchexposed.com/
But he said he could tell that my stomach and spleen
ReplyDeletewere shot to bits, because my tongue was swollen and quivering.
In October 2007, Pamela married Rick Salomon but after the
couple separated two months later she asked the courts to annul the marriage citing fraud.
Many dentists, however, weight loss and reduction in cholesterol.
my web site :: dermology cellulite Solution