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What is the method by which cells excrete proteins and how does it start in the endoplasmic reticulum?
Wiki User
∙ 12y ago
Cells excrete proteins via exocytosis, where the proteins are pinched of the Golgi apparatus in vesicles. These vesicles then fuse with the cell surface membrane, thus expelling them from the cell.
The entire process is Protein Traffiking, where it starts by being absorbs into the RER (rough endoplasmis reticulum) and is modified and activated during its journey to the outside of the cell.
You're welcome.
Wiki User
∙ 12y ago
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Why do proteins that move to the nucleus tend not to contain an N-terminal signal peptide?
The N-terminal signal peptide is recognised by SRP (signal recognition particle). SRP directs the peptide to translocons on the membrane of the rough endoplasmic reticulum, usually during translation (co-translational). The translocon is responsible for the transport of the protein into the endoplasmic reticulum, from which it will either be secreted or sent to organelles such as the mitochondria, chloroplasts, endosome, lysomome and peroxisome. These organelles require that proteins go through the endoplasmic reticulum as the proteins are incorporated into the organelles through vesicular transport, as they do not have their own uptake methods. Proteins destined for the nucleus are not sent through the endoplasmic reticulum, as the method of transport into the nucleus is not vesicular. Instead, the nucleus has its own pores capable of translocating proteins into the nucleus. Small objects can pass through these nuclear pores by passive transport, but anything bigger than 40kDa requires a special mechanism. Proteins destined for the nucelus have a nuclear-localisation signal (NLS) instead of the N-terminal signal peptide. The NLS is a seven residue sequence of basic amino acids at the C-terminus.
Is the method for protein synthesis different in animals plants and bacteria?
No. This is one of those things that has been "conserved" over evolutionary time. It has worked well from the very beginning and so has been used again and again. The only thing that is different is where it takes place and their size. In bacteria, ribosomes are found in the cytoplasm and in our cells, they are usually found embedded in the rough endoplasmic reticulum. The size of bacteria ribosomes are smaller.
What is the structure of the vesicle membrane?
membrane phospolipids
Are proteins a solid?
Proteins are solute molecules found in a dissolved form in buffer. Proteins can be crystallized to form a crystal (solid) by evaporation. This method is used in protein X-ray crystallography to solve its 3D structure.
First reports of the use of sucrose for gel electrophoresis?
Gel electrophoresis is the analysis and separation method of DNA, RNA and proteins. The first reported use of this method was in 1930s.
Why do proteins that move to the nucleus tend not to contain an N-terminal signal peptide?
The N-terminal signal peptide is recognised by SRP (signal recognition particle). SRP directs the peptide to translocons on the membrane of the rough endoplasmic reticulum, usually during translation (co-translational). The translocon is responsible for the transport of the protein into the endoplasmic reticulum, from which it will either be secreted or sent to organelles such as the mitochondria, chloroplasts, endosome, lysomome and peroxisome. These organelles require that proteins go through the endoplasmic reticulum as the proteins are incorporated into the organelles through vesicular transport, as they do not have their own uptake methods. Proteins destined for the nucleus are not sent through the endoplasmic reticulum, as the method of transport into the nucleus is not vesicular. Instead, the nucleus has its own pores capable of translocating proteins into the nucleus. Small objects can pass through these nuclear pores by passive transport, but anything bigger than 40kDa requires a special mechanism. Proteins destined for the nucelus have a nuclear-localisation signal (NLS) instead of the N-terminal signal peptide. The NLS is a seven residue sequence of basic amino acids at the C-terminus.
What Does smooth ER and rough ER do?
The ER is involved with the production, processing, transport, and storage of materials inside a cell. The difference between the Smooth and Rough one is that the rough one is associated with ribosomes whereas the smooth one lacks ribosomes. Hope this was helpfull :)
Where is the smooth er located in a cell?
The smooth e.r. (endoplasmic reticulum) is located in the cytoplasm of eukaryotic cells. Like the rough e.r., the smooth e.r. is concerned with making proteins. Unlike the rough e.r., the smooth e.r has no ribosomes attached to it. Hope this helps. The whole article is on Wikipedia, in case this didn't help (see related link).
What is the Bradford method?
The Bradford method involves a chemical test. It is used by scientists to determine the concentration of proteins in a solution.
Method of separating out plasma proteins by electrical charge?
Electrophoresis
Is the method for protein synthesis different in animals plants and bacteria?
No. This is one of those things that has been "conserved" over evolutionary time. It has worked well from the very beginning and so has been used again and again. The only thing that is different is where it takes place and their size. In bacteria, ribosomes are found in the cytoplasm and in our cells, they are usually found embedded in the rough endoplasmic reticulum. The size of bacteria ribosomes are smaller.
What is the structure of the vesicle membrane?
membrane phospolipids
What are transportation proteins?
In one method, transport proteins in the cell membrane "pick up" molecules outside the cell and carry them in, using energy. Transport proteins also carry molecules out of cells in a similar way.
Are proteins a solid?
Proteins are solute molecules found in a dissolved form in buffer. Proteins can be crystallized to form a crystal (solid) by evaporation. This method is used in protein X-ray crystallography to solve its 3D structure.
First reports of the use of sucrose for gel electrophoresis?
Gel electrophoresis is the analysis and separation method of DNA, RNA and proteins. The first reported use of this method was in 1930s.
Birds excrete a concentrated form of nitrogeneous waste known as?
Uric acid in paste form. Energetically more expensive an excretory method, but I forget why they use the uric acid excretion.
What is the advantage of adding SDS to gel electrophoresis?
SDS PAGE electrophoresis is an important method in the separation of proteins. it can be use to identify and isolate proteins aswell as determine if a protein solution is pure or contaminated
