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Proteins
Proteins are the macromolecules coded in our DNA that function as a biocatalyst and build our body. Apart from Biological knowledge, there are spectacular concepts in the field of proteins. How does a protein produce a function, how do they interact, how did they evolve and how do protein mutations cause disease.
460 Questions
What is the major building block for proteins?
The major and basic building blocks of proteins are the amino acids.
What makes proteins three-dimensional?
Hydrophobic interactions cause proteins to form into a three-dimensional shape.
What is the main difference between protein electrophoresis and nucleic acid electrophoresis?
There are many similarities and differences between protein and DNA electrophoresis.
Similarities:
- PAGE protein and DNA electrophoresis both cause separation by size, creating bands that are viewed by the scientist or a machine. The smallest segments more the fastest due to less friction with the surface of their medium or equipment.
- The movement of charges through the medium is what causes the DNA or proteins to move. Electrons move from the negative to positive end of the gel or capillary tube.
Differences:
- In PAGE protein electrophoresis, a polyacrylamide gel is used to prevent convection from altering the movement of the proteins. If the proteins are charged, and there is a worry that the charge will affect the mobility of the protein segments, 1% SDS can be added to get rid of the mass/charge issue. This way, only the mass of the segment determines how far it moves. In DNA capillary electrophoresis, the size of the capillary is so small that it does not have room for convection to occur (it is only 20-50 microns wide). Thus, there is no medium in the capillary but DNA itself.
- In protein electrophoresis, the proteins are often dyed so their movement can be viewed with the naked eye, or a machine. With DNA capillary electrophoresis, DNA strands are made through DNA replication with dNTPs that are fluorescently labeled for the different nucleotides. Each base is labeled a different color. A fine laser lights up the DNA strand in the capillary tube and reads what color fluoresces. This is how the nucleotide is identified.
- Protein PAGE electrophoresis is used to determine the purity of a protein sample. It can also be used to see how large the chains are that make up a multi-chain protein if a denaturing agent is added. DNA electrophoresis is used to get the order of nucleotides in a DNA sequence. It is done by chopping the DNA sequence into many smaller bits and sequencing them, then putting them back together by lining them up according to sequence overlaps. This is called the "shotgun" method. Protein electrophoresis can figure out the order of about 15-20 amino acids by a similar method, but DNA electrophoresis can get up to 1000 nucleotides (~300 amino acids). DNA electrophoresis is limited by the low probability that the DNA sequence would be cut into a segment greater than 1000 nucleotides.
Is the nucleus the site of protein assembly?
No. The protein assembly, or protein synthesis, is taking place in the cytosol, particularly in the ribosomes.
What proteins are found in chromatin?
You may be looking for the term "histones," which are the protein component of chromatin (which comprises chromosomes).
Histones are proteins around which DNA winds, making it dense and compact; this results in the denser form of chromatin, known as "heterochromatin." Histones thus play a role in regulating the expression of genes (because they cannot be expressed whilst compacted). When histones are modified, they can change shape or charge and release the tightly-wound DNA so that the genes can be expressed; this looser form of chromatin is known as "euchromatin."
Together, heterochromatin and euchromatin make up chromosomes.
http://en.wikipedia.org/wiki/Histone
Who modifies and packages new synthesized proteins?
The Golgi Apparatus modifies and packages newly synthesized proteins sent from the Rough Endoplasmic Reticulum.
Yes. The major proteins found in plasma are fibrinogen, the protein that helps the blood to clot, antibodies, and enzymes.
What is the Folding of proteins?
Protein folding determines the shape of the protein, and thus what it does, because it is the shape of the protein which enables it to perform its function. For example, enzymes need to have exactly the right shape to fit with the molecules they are working with to catalyze them. Also, hemoglobin is specifically folded with four pocket like areas to allow oxygen to attach to it. The shape of the protein is specific to the function that it is performing, and is different for each protein. If there is even a slight change in the make up of the protein, or a mutation (the amino acids are messed up) then the protein will fold differently. Even a slight change in the composition of the protein can disable the protein from properly performing the function which it is meant to do.
What proteins are in globular proteins?
There are two class of protein based on their structure namely fibrous and globular. Globular proteins form a globe like spherical structure in contrary to rod like fibrous proteins (collagen). They are soluble in water and the structure is rendered by its three dimensional arrangement of amino acids in solution. Most of the enzymes, soluble hormones and factors fall into this class of proteins.
Name three functions of proteins?
- Protein is necessary for the building and repair of body tissues.
- It produces enzymes, hormones, and other substances the body uses.
- It regulates body processes, such as water balancing, transporting nutrients, and making muscles contract.
- Protein keeps the body healthy by resisting some diseases common in people who are malnourished.
- It may prevent you from becoming easily fatigued, because your body can use protein for energy if necessary.
Which cellular organelle is responsible for packaging the proteins the cell secrets?
Sercretory vesicles are derived from Golgi bodies. After synthesis, proteins are modified in ER and transported to golgi bodies. Theses vesicles will then transport or secrete out the proteins similar to exocytosis.
How many molecules of water are formed when 4 amino acids bond?
For every peptide bond there is one water molecule
What do proteins provide for the cell?
Cells are structural and functional units of living organisms therefore they make the structure of living organisms and they also tells the body that how to function. Azhar Khan azhar_saeed39@yahoo.com
Does proteins determine Genes?
No, proteins do not determine genes. Genes are segments of DNA that encode instructions for making proteins. Proteins are the products of gene expression, meaning that genes are responsible for determining the sequence and structure of proteins.
What is the denaturation of a protein?
Denaturation of a protein is the process by which a protein loses its structure and function due to changes in its environment, such as heat, pH, or chemicals. This can disrupt the interactions that maintain the protein's shape, leading to unfolding and loss of biological activity.
Are there toxic proteins in vegetables?
Some proteins can indeed be toxic. However, note that it is rare for a protein to be toxic.
Yes pathogens produce and secrete toxic proteins to invade their host. Bacterial toxin such as hemolysin A, neurotoxin, botulinum toxin, tetanus toxin, Shiga toxin are all proteins. They are strongly antigenic can elicit immune response.
What happens after the synthesis of proteins?
After proteins get modified in the Endoplasmic Reticulum, they are transported through the golgi apparatus where they get packaged into vesicles to late be secreted out of the cell or to be used within the cell.
Can proteins pass through transport proteins?
No the soluble proteins can not pass though the transporters on the membrane. Transport proteins are highly specific they only allow the transport of ions such as Na or K across the cell. But transport proteins such as Hemoglobin can carry oxygen or CO2 to all the tissues for respiration.
What is a passageway in a cell for proteins?
Proteins enter and leave the cell through endocytosis and exocytosis, respectively.
