Các bệnh liên quan đến trao đổi chất qua màng
- Thread starter mura12345
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Duyên Anh
Senior Member
The phospholipid bilayer is oily and many of the proteins move within it like ships on a sea. The inner hydrophobic region of the phospholipid bilayer blocks entry and exit to most substances that dissolve in water. However, certain molecules can cross the membrane through proteins that form passageways, or when they are escorted by a “carrier” protein. Some membrane proteins form channels for ions, which are atoms or molecules that bear an electrical charge. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com
fficeffice" /><o></o>
All result from abnormal ion channels in cell membranes. Ion channels are protein-lined tunnels in the phospholipid bilayer of a biological membrane. These passageways permit electrical signals to pass in and out of membranes<o></o>
in the form of ions (charged particles).<o></o>
Ion channels are specific for calcium (Ca+2), sodium (Na+), potassium (K+), or chloride (Cl–). A cell membrane may have a few thousand ion channels specific for each of these ions. Ten million ions can pass through an ion channel in one second! The following disorders result from abnormal ion channels.<o></o>
Hyperkalemic Periodic Paralysis and Sodium Channels<o></o>
The quarter horse was originally bred in the 1600s to run the quarter mile, but one of the four very fast stallions used to establish much of today’s population of 3 million animals inherited hyperkalemic periodic paralysis (HPP). The horse, otherwise a champion, collapsed from sudden attacks of weakness and paralysis.<o></o>
HPP results from abnormal sodium channels in the cell membranes of muscle cells. But the trigger for the temporary<o></o>
paralysis is another ion: potassium. A rising blood potassium level, which may follow intense exercise, slightly alters a muscle cell membrane’s electrical charge. Normally, this slight change would have no effect, but in horses with HPP, sodium channels open too widely, allowing too much sodium into the cell. The muscle cell cannot respond to<o></o>
nervous stimulation for awhile, and the racehorse falls.<o></o>
People can inherit HPP, too. In one family, several members collapsed suddenly after eating bananas! These fruits are very high in potassium, which caused the symptoms.<o></o>
Long-QT Syndrome and Potassium Channels<o></o>
Four children in a Norwegian family were born deaf, and three of them died at ages four, five, and nine. All of the children had inherited from unaffected carrier parents long-QT syndrome associated with deafness.<o></o>
(“QT” refers to part of a normal heart rhythm on an EKG.) They had abnormal potassium channels in the heart muscle and in the inner ear. In the heart, the malfunctioning channels disrupted electrical activity, causing a fatal disturbance to the heart rhythm. In the inner ear, the abnormal channels caused an increase in the extracellular concentration of potassium ions, impairing hearing.<o></o>
Cystic Fibrosis and Chloride Channels<o></o>
A 17th century English saying, “A child that is salty to taste will die shortly after birth,” described the consequence of abnormal chloride channels in CF. The chloride channel is called CFTR, for cystic fibrosis transductance regulator. In most cases of CF, CFTR protein remains in the cytoplasm, unable to reach the cell membrane, where it would unction (see figure 2.1b). CF is inherited from carrier parents. The major symptoms of difficulty breathing, frequent<o></o>
severe respiratory infections, and a clogged pancreas that disrupts digestion all result from buildup of extremely thick mucous secretions.<o></o>
Abnormal chloride channels in cells lining the lung passageways and ducts of the pancreas cause the symptoms of CF.The primary defect in the chloride channels also causes sodium channels to malfunction. The result: salt trapped inside cells draws moisture in and thickens surrounding mucus.<o></o>
<o> </o>
Human Genetics-Concepts and Applications
fficeffice" /><o></o>All result from abnormal ion channels in cell membranes. Ion channels are protein-lined tunnels in the phospholipid bilayer of a biological membrane. These passageways permit electrical signals to pass in and out of membranes<o
></o>in the form of ions (charged particles).<o
></o>Ion channels are specific for calcium (Ca+2), sodium (Na+), potassium (K+), or chloride (Cl–). A cell membrane may have a few thousand ion channels specific for each of these ions. Ten million ions can pass through an ion channel in one second! The following disorders result from abnormal ion channels.<o
></o>Hyperkalemic Periodic Paralysis and Sodium Channels<o
></o>The quarter horse was originally bred in the 1600s to run the quarter mile, but one of the four very fast stallions used to establish much of today’s population of 3 million animals inherited hyperkalemic periodic paralysis (HPP). The horse, otherwise a champion, collapsed from sudden attacks of weakness and paralysis.<o
></o>HPP results from abnormal sodium channels in the cell membranes of muscle cells. But the trigger for the temporary<o
></o>paralysis is another ion: potassium. A rising blood potassium level, which may follow intense exercise, slightly alters a muscle cell membrane’s electrical charge. Normally, this slight change would have no effect, but in horses with HPP, sodium channels open too widely, allowing too much sodium into the cell. The muscle cell cannot respond to<o
></o>nervous stimulation for awhile, and the racehorse falls.<o
></o>People can inherit HPP, too. In one family, several members collapsed suddenly after eating bananas! These fruits are very high in potassium, which caused the symptoms.<o
></o>Long-QT Syndrome and Potassium Channels<o
></o>Four children in a Norwegian family were born deaf, and three of them died at ages four, five, and nine. All of the children had inherited from unaffected carrier parents long-QT syndrome associated with deafness.<o
></o>(“QT” refers to part of a normal heart rhythm on an EKG.) They had abnormal potassium channels in the heart muscle and in the inner ear. In the heart, the malfunctioning channels disrupted electrical activity, causing a fatal disturbance to the heart rhythm. In the inner ear, the abnormal channels caused an increase in the extracellular concentration of potassium ions, impairing hearing.<o
></o>Cystic Fibrosis and Chloride Channels<o
></o>A 17th century English saying, “A child that is salty to taste will die shortly after birth,” described the consequence of abnormal chloride channels in CF. The chloride channel is called CFTR, for cystic fibrosis transductance regulator. In most cases of CF, CFTR protein remains in the cytoplasm, unable to reach the cell membrane, where it would unction (see figure 2.1b). CF is inherited from carrier parents. The major symptoms of difficulty breathing, frequent<o
></o>severe respiratory infections, and a clogged pancreas that disrupts digestion all result from buildup of extremely thick mucous secretions.<o
></o>Abnormal chloride channels in cells lining the lung passageways and ducts of the pancreas cause the symptoms of CF.The primary defect in the chloride channels also causes sodium channels to malfunction. The result: salt trapped inside cells draws moisture in and thickens surrounding mucus.<o
></o><o
> </o>Human Genetics-Concepts and Applications
Lewis
The McGraw−Hill
Companies, 2003
The McGraw−Hill
Companies, 2003
cảm ơn chị đã trả lời giúp em nhưng mà toàn tiếng anh thế này thì em chưa thể đọc hết được. Ai có khả năng thì dịch hộ em với ah. Cám ơn nhiều ah
Ơ em nhờ anh google dịch hộ ý.
mura12345
Senior Member
Hic ,em đã nhờ nhiều rồi cũng chỉ tìm được 1 phần thôi còn dich tiếng anh thì thực sự là em chưa đủ thời gian mà bài thì sắp phải nộp rồi và hầu hết những bênh lí liên quan đến màng sinh học là bệnh trong cơ chế tiếp nhận thông tin , thu nhận hoocmon còn liên quan đến trao đổi chất qua màng chí tìm được vài bệnh thôi
- liên quan đến kênh vận chuyến nước: hình như cơ chể gây bênh tả chính là làm hỏng kênh vận chuyển nước nên tế bào liên tục bơm nước ra ngoài lam f cơ thể mất nước và các chất điện giải
- liên quan đến bơm K+: gây hội chứng Andersen
- liên quan đến bơm Ca2+ : gây bênh Hailey
dù sao em vẫn mong tìm thêm 1 số bệnh nữa liên quan đến màng sinh chất và có cơ chể tác đông thi càng tốt ạ
- liên quan đến kênh vận chuyến nước: hình như cơ chể gây bênh tả chính là làm hỏng kênh vận chuyển nước nên tế bào liên tục bơm nước ra ngoài lam f cơ thể mất nước và các chất điện giải
- liên quan đến bơm K+: gây hội chứng Andersen
- liên quan đến bơm Ca2+ : gây bênh Hailey
dù sao em vẫn mong tìm thêm 1 số bệnh nữa liên quan đến màng sinh chất và có cơ chể tác đông thi càng tốt ạ
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