Answer:
The shape of the enzyme determines which chemical reaction it will speed up.May strain the bonds of the substrate or put chemical groups of the active site in the correct position to speed up the reaction.
* More than 40 proteins and glycoproteins involved in the complement system are synthesized by the liver, macrophages, epithelial cells, they are present in the blood in plasmatic form, membrane, some have an enzymatic activity, regulator or membrane receptorThese are elements of the humoral innate immune response, they fight infections, purify immune complexes and apoptotic bodies.
<span>There are indeed three ways to activate the complement:</span>
Classical pathway: Activated by Immunoglobulins in immune complexes, aggregated Immunoglobulins, DNA, CRP, apoptotic bodies .......it involves nine fractions, starting with C1, then C4, C2, C3, to form a classical C5 convertase, then, activation of C5, C6, C7, C8, C9.
Alternative pathway: activated by polysaccharides (bacterial endotoxin), vascular wall poor in sialic acid, aggregated IgE ...C3b like is the first component in the alternate channel cascade, it will create an amplification loop, and form an alternative C5 convertase.
Lecithin pathway: Activated by mannose, fucose (carbohydrate of microorganisms)The first component is the complex MBL / MASP1 / MASP2: "mannose-binding protein": works according to the same principle as the complex C1 of the classical way (MASP2 cleaves the C4 and the rest of the cascade is equivalent to that of the classical way).
the three ways have the same outcome: A C5 convertase (formed by one of the pathways) cleaves C5 into C5a and C5b: C5b is deposited far from other fractions on the antigenic surface. The fixation of C5b in the cell is followed by that of C6, C7, C8, and C9 (9 molecules of C9): formation of the membrane attack complex (MAC) ==> Death of the cell by osmotic shock
Answer:
B. A sperm cell
Explanation:
Meiosis creates gametes/sex cells, such as the sperm and egg.
So, sperm cells are formed by meiosis.
Meiosis doesn't create fertilized eggs, it instead creates normal egg cells.
Meiosis also doesn't create heart and bacterial cells because those are made in mitosis.
So, B is the correct answer.
Tertiary Structure<span> - refers to the comprehensive 3-D structure of the polypeptide chain of a </span>protein<span>. There are several types of bonds and forces that hold a protein in its tertiary structure. </span>Hydrophobic interactions<span> greatly contribute to the folding and shaping of a protein. The "R" group of the amino acid is either hydrophobic or hydrophilic. The amino acids with hydrophilic "R" groups will seek contact with their aqueous environment, while amino acids with hydrophobic "R" groups will seek to avoid water and position themselves towards the center of the protein. </span>Hydrogen bonding<span> in the polypeptide chain and between amino acid "R" groups helps to stabilize protein structure by holding the protein in the shape established by the hydrophobic interactions. Due to protein folding, </span>ionic bonding<span> can occur between the positively and negatively charged "R" groups that come in close contact with one another. Folding can also result in covalent bonding between the "R" groups of cysteine amino acids. This type of bonding forms what is called a </span>disulfide bridge<span>. </span>Primary Structure - describes the unique order in which amino acids are linked together to form a protein. Proteins are constructed from a set of 20 amino acids. <span>All amino acids have the alpha carbon bonded to a hydrogen atom, carboxyl group, and amino group. The </span>"R" group<span> varies among </span>amino acids<span> and determines the differences between these protein monomers. The amino acid sequence of a protein is determined by the information found in the cellular</span>genetic code<span>. The order of amino acids in a polypeptide chain is unique and specific to a particular protein. Altering a single amino acid causes a </span>gene mutation, which most often results in a non-functioning protein.
<span>Secondary Structure - refers to the coiling or folding of a polypeptide chain that gives the protein its 3-D shape. There are two types of secondary structures observed in proteins. One type is the alpha (α) helix structure. This structure resembles a coiled spring and is secured by hydrogen bonding in the polypeptide chain. The second type of secondary structure in proteins is the beta (β) pleated sheet. This structure appears to be folded or pleated and is held together by hydrogen bonding between polypeptide units of the folded chain that lie adjacent to one another.
</span><span>Quaternary Structure - refers to the structure of a protein macromolecule formed by interactions between multiple polypeptide chains. Each polypeptide chain is referred to as a subunit. Proteins with quaternary structure may consist of more than one of the same type of protein subunit. They may also be composed of different subunits. Hemoglobin is an example of a protein with quaternary structure. Hemoglobin, found in the blood, is an iron-containing protein that binds oxygen molecules. It contains four subunits: two alpha subunits and two beta subunits.
I hope this helped you find the answer you were looking for!
</span>
