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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 plasma proteins are complement proteins?
Complement proteins are a series of immune proteins that carry out complement cascade reactions. These proteins are helping the immune system to lean up from the cells. complement proteins are not antibodies.
Does hemoglobin have proteins?
Hemoglobin is an iron-containing protein. Hemoglobin contains a hemo prosthetic group that has an iron atom at its center. When the iron is bound to oxygen, the hemo group is red in color (oxyhemogoblin), and when it lacks oxygen (deoxygenated form) it is blue-red.
What is the key feature of a protein or enzyme that makes its function correctly?
The most important feature that makes functional to a protein or an enzyme is its three dimensional structure based on its tertiary structure. Either, a structural protein, where alpha helices and beta sheets are vital to its function, or an enzyme, where the shape of its active site is crucial for its biological activity, the tertiary structure is the most important characteristic. In fact, the process called "protein folding" is one of the key biochemical areas of study for the scientific community.
What are the final products of proteins?
In prokaryotic cells, mRNA is directly produced.
In eukaryotic cells, the first product is called the primary transcript.
What do proteins determine in an organism?
The genes determine the amino sequence and the shape the amino group will be folded into to become a protien.
What are the key elements to proteins?
Protein are the chief functionary in a given cell. As such they ar elarge biological molecules thatconsist of several chains of amino acid. Protein can be folded into one of several three dimensional structures and it is this formation that denotes its specific role to perform.
What is the order in which proteins are synthesized?
An export protein starts its journey where it is created, the ribosomes. Next it travels to the Rough ER where it assists in moving the protein to the Golgi Apparatus. At the Golgi the protein is "packaged and shipped" to the cell membrane where it leaves the cell.
Yes. Each codon specifies an amino acid or start or stop. A sequence of codons from start to stop is a gene and specifies a protein.
note. this answer is about 98% accurate. Many minor differences are known and more remain to be discovered. What is known already fills a small book.
What is the name of the defensive proteins?
Proteins that are involved in our body immune system are called antibodies or immunoglobulins (IgG) produced by B cells. There are different kind of Immunonoglobulins IgA, IgM, IgG (antibodies). In addition, cytotoxins, histamines, interferons, tumour necrosis factors are also produced by white blood cells to defend us from pathogens.
Why is protein conformation important?
A protein's shape is very important for its function. For example, enzymes react with substrates at an active site. This is very specific and if the shape changes, it will not react at efficiently (or at all).
What is the structure of receptor proteins?
Receptors are plasma membrane proteins that bind specific molecules, e.g., growth factors, hormones, or neurotransmitters, and then transmit a signal to the cell's interior that causes the cell to respond ina aspecific manner, a process called signal transduction cascade.
There are several types of receptor proteins grouped in families of transmembrane proteins. For some families of important membrane proteins, e.g., ion channel proteins, the hydropathy plots (those that help to predict the hydrophobic regions of a membrane protein according to its amino acid sequence and hydropathic index) is often not very reliable because that the membrane-spanning regions of these proteins from channels in the membrane while on the other hand they need hydrophilic residues to line the surface of the channels in contact with the aqueous phase. These are the most important and most well-known receptor-protein families:
- Receptor Protein-Tyrosine Kinases. Known as RPTKs, are type I transmembrane proteins, with their N-termini outside of the cell and single membrane-spanning regions. The structural features that are the transmembrane domain that divides the molecule into a ligand-binding domain and a cytoplasmic domain that contains a conserved protein kinase catalytic domain. On the outside, the N-terminal end, RPTK has a signal peptide that ensures that the protein will be targeted to the secretory pathway. This is followed by an extracellular domain of several hundred amino acids that contain N-linked glycosilation sites, a distintive pattern of cysteine residues, and often a characteristic array of structural motifs. The transmembrane domain consists of about 24 hydrophobic residues that are usually succeeded by several basic residues that function as a stop-transfer signal. On the cytoplasmic side of the membrane there is a juxtamembrane region, usually of around 50 residues long, and which in some cases is known to have important regulatory functions. Next follows the catalytic domain, which is related to the catalytic domains of the cytoplasmic protein-tyrosine kinases and the protein-serine/threonine kinases, and is about 250 residues in length, excluding inserts. The phospho-transfer function lies entirely whithin this region. The region C-terminal to the catalytic domain is of variable length and can be up to 200 residues. The functions of this C-terminal tail vary among members of the RPTKs. Exmaples of this kind of receptors are: EGFR (Epidermial Growth Factor Receptor), PDGFR (Platelet-Derived Growth Factor Receptor), IR (Insulin Receptor), NGFR (Nerve Growth Factor Receptor), FGFR (Fibroblast Growth Factor Receptor), etc.
- G proteins. Several important physiological responses like vision, smell, and stress response produce large metabolic effects from a small number of input signals. The receptors for these signals have two things in common, first, they are transmembrane proteins with seven helices spanning the lipid bilayer of the plasma membrane, and second, the signals received by these receptors are amplified and the amplifiers are members of a common family of proteins called G proteins. Most G proteins are heterotrimers consisting of a one copy of alpha (45 kD), beta (35 kD), and gamma (7 kD) subunits. The alpha subunits have GTPase activity and slowly hydrolyze GTP to GDP and inorganic phosphate. The GTP-bound form of the protein is the active form and sends a signal from the receptor to some cellular effector protein. Examples of these kind of receptors are: beta-adrenergic receptor, rhodopsin, mast cell IgE receptor, and muscarinic receptor.
Which organelle makes proteins in a cell?
Proteins are made by ribosomes. They are the protein synthesizing factories
What are chromatin proteins called?
Chromatin is the name of the mixture of DNA and proteins that are found in the nucleus of a cell. Depending on the stage of the cellular cycle, the chromatin may be structured differently, ranging from loosely to tightly structured.
What do plants use to produce proteins?
yes plant have protein for living
Plants, animals, bacteria, virus, and all known life forms do have proteins. They are coded in their genetic material (DNA or RNA). Proteins are synthesized in the cytoplasm of the cell.
How are proteins positioned within the membrane?
The protein is anchored into the membrane by its nonpolar region, but the protein remains moblie. To explain it more, the middle section of the protein is made of many nonpolar amino acids. This nonpolar coil fits into the nonpolar interior of the lipid bilayer allowing the protein to float in the membrane.
What is the main function of proteins?
Proteins are fundamental components of all living cells and include many substances, such as enzymes, hormones, and antibodies, that are necessary for the proper functioning of an organism. They are essential in the diet of animals for the growth and repair of tissue and can be obtained from foods such as meat, fish, eggs, milk, and legumes.
Your body uses the protein you eat to make lots of specialized protein molecules that have specific jobs. For instance, your body uses protein to make hemoglobin, the part of red blood cells that carries oxygen to every part of your body. Other proteins are used to build cardiac muscle. What's that? Your heart! In fact, whether you're running or just hanging out, protein is doing important work like moving your legs, moving your lungs, and protecting you from disease
Read more: protein
What do trans-membrane proteins do?
I trans membrane protein is located in the plasma membrane. It can be found in organelles such as the endoplasmic reticulum or on the phospholipd bilayer surrounding cells. Each end of the protein (the C-terminus (COOH) or N-terminus (NH2)) is located on opposite sides of the membrane. For example if located in the membrane of the ER, one one end of the protein would be in the ER lumen and the other in the cells cytoplasm.
The proteins are 'anchored' into the membrane by hydrophobic regions which are easily accommodated in the hydrophobic membrane.
Proteins is considered the building blocks what?
Proteins are the main building blocks for tissues including muscle, hair, nails, skin, eyes, internal organs, nerves, ligaments, tendons, cartilage and membranes. They are also the building blocks of cells, cellular membranes, organelles--all the way to the level of DNA and genes.
What is it called when a protein folds back onto itself?
a. tertiary structure
b. primary structure
c. secondary structure
d. tertiary structure
pick your best answer
What are all the kinds of proteins?
on the basis of chemical structure and solubility: globular protein; albumin;globulin;proalamines and histones
on the basis of functions: structural protein;enzymes and catalyst protein;transport protein,hormonal p.; contractile p.; storage p.; genetic p.; defence p.; and receptor protein.
What is the main role for proteins?
Intrinsic proteins are the integral proteins inside the plasma membrane, or phospholipid bilayer, of a cell. The reason they are called intrinsic is because they cannot be released unless the membrane is disrupted.
Why and how does the proteins fold?
A protein is driven into its structure
by hydrophobic interactions with water. The final folding
of a protein is determined by its primary structure-by the
chemical nature of its side groups. Many proteins can be
fully unfolded ("denatured") and will spontaneously refold
back into their characteristic shape.
The stability of a protein, once it has folded into its 3-D
shape, is strongly influenced by how well its interior fits
together. When two nonpolar chains in the interior are in
very close proximity, they experience a form of molecular
attraction called van der Waal's forces. Individually quite
weak, these forces can add up to a strong attraction when
many of them come into play, like the combined strength
of hundreds of hooks and loops on a strip of Velcro. They
are effective forces only over short distances, however;
there are no "holes" or cavities in the interior of proteins.
That is why there are so many different nonpolar amino
acids (alanine, valine, leucine, isoleucine). Each has a different
sized R group, allowing very precise fitting of nonpolar
chains within the protein interior. That's
why a mutation that converts one nonpolar amino
acid within the protein interior (alanine) into another
(leucine) very often disrupts the protein's stability; leucine
is a lot bigger than alanine and disrupts the precise way the
chains fit together within the protein interior. A change in
even a single amino acid can have profound effects on protein
shape and can result in loss or altered function of the
protein.
How are DNA RNA and proteins related?
The sequence of the bases on DNA is copied as a sequence of bases on RNA (messenger RNA). This is finally translatedinto a sequence of amino acids in the protein which determines the protein's structure and function.
