Answer:
Cell membrane
Explanation:
Cell membrane controls what goes in and out of cells
Answer:
b. reducing molecules
Explanation:
Nicotinamide adenine dinucleotide (abbreviated NAD +, and also called diphosphopyridine nucleotide and Coenzyme I), is a coenzyme found in all living cells. The compound is a dinucleotide, as it consists of two nucleotides linked through their phosphate groups with a nucleotide that contains an adenosine ring and the other that contains nicotinamide.
In metabolism, NAD + participates in redox reactions (oxidoreduction), carrying electrons from one reaction to another.
Coenzyme, therefore, is found in two forms in cells: NAD + and NADH. NAD +, which is an oxidizing agent, accepts electrons from other molecules and becomes reduced, forming NADH, which can then be used as a reducing agent to donate electrons. These electron transfer reactions are the main function of NAD +. However, it is also used in other cellular processes, especially as a substrate for enzymes that add or remove chemical groups of proteins, in post-translational modifications. Due to the importance of these functions, the enzymes involved in the metabolism of NAD + are targets for drug discovery.
Answer:
Hemoglobin is responsible for binding and transporting oxygen in the body. It is a tetrameric protein that is found in high concentration in red blood cells (erythrocytes, red blood cells). Each hemoglobin molecule is made up of four subunits: two of the alpha type and two of the beta type, and each subunit can bind an oxygen molecule through its heme group.
Structure studies have shown that hemoglobin can adopt two conformations, called T (tense) and R (relaxed). Deoxyhemoglobin (in blue) is in state T, and the union of oxygen (in red) causes the transition to state R. The animation shows a close view of the heme group (in white, balls and rods) of one of the subunits of hemoglobin. In the deoxygenated state (T), the iron atom is not coplanar with the rest of the heme group due to its association with the histidine side chain. The union of oxygen displaces the iron atom so that it remains coplanar with the rest of the heme group, which in turn drags histidine, producing a larger-scale conformational change that affects the entire protein.
Hemoglobin can be considered as a tetramer formed by two alpha-beta dimers. The conformational change associated with the transition from T to R mainly affects the relative position of these two dimers (rather than the interactions between the alpha and beta subunits within a dimer). This is illustrated in the last stretch of the animation (drawn in black and white).
Answer:
i think C
Explanation:
Natural selection is the process where organisms better adapted to their environment tend to survive and produce more offspring.
Answer: adaptive immune response
Explanation:
Autoimmune disorders are caused by different microoorganism and drug which manipulates the immune system in a way that immune system become unable to recognise between self antigen and foreign antigen. In that case immune system treats foreign antigen as self antigen which cause systemic or organ specific damage.
The exact cause of autoimmune disorders is unknown and hence it is thought that it is caused by adaptive immune response which builds against self antigens and causes damage to the cells.
Hence, some autoimmune disorders are thought to be caused by adaptive immune response.
