Immunology Coursework Example | Topics and Well Written Essays - 1000 words

Immunology - Coursework Example In 1 sentence or less, explain what could explain the failure of this vaccine. 21. In 2002, Diane Mathis and colleagues discovered the function a molecule named AIRE that was critical for the prevention of multi-organ autoimmune disease. How would you best describe the function of AIRE? Vaccination refers to the injection of a microbe so as to accelerate the immune system to counter the microbe, thus preventing disease. Immunizations or Vaccinations, work through stimulation of the immune system. The fundamental concern, it is impractical to manage cellular processes to make sure that a virus that is replication-deficient will not naturally become replication-competent. If a virus turns into replication-competent, it possibly will re-acquire any characteristics of pathogenic connected to the wild-type germ and could lead to illness. Lymphocytes are believed to enter the lymph nodes through a cascade of steps. Step 1: Cells initially roll on and tether endothelium via selectin-mediated interactions; then go through a stimulated improvement in integrin activity (step 2. It then triggers them to abide firmly by endothelium through the connection of Ig super-family molecules of adhesion and integrins (step 3). The cells that are firmly attached then trail a chemoattractant incline into tissues (step 4). The integrins and selectins necessary for the first step involve L-selectin. Step 3 requires lymphocyte integrin LFA-1 (aLb2) that mediates firm adhesion through obliging to its ICAM-1, HEV-expressed counter-receptors. The molecules that are efficient in performing step 2 and step 4 functions are Chemokines. CD28 and CTLA-4 are homologs, which each bind B7; however, have opposing roles. Even though CD28 co-stimulates T cells, CTLA-4 prevents activation of T cells through blocking cell cycle progression and cytokine production. CTLA-4 is swiftly induced after activation of T cells and has remarkable inhibitory properties.

Photosynthesis Essay Example | Topics and Well Written Essays - 500 words

Photosynthesis - Essay Example The molecule is made up of a porphyrin ring with several carbon and nitrogen bonds and a magnesium ion in the center (Starr et al., 2009). The first part of photosynthesis is the light dependent reaction occurring in the thylakoid membrane. Here chlorophyll and other accessory pigments like beta carotene absorb different wavelengths of light in the antenna complex (Starr et al., 2009). When one chlorophyll pigment absorbs a photon of light in photosystem II, the molecule reaches a higher energy state, exciting its electron. This excitation results in the loss one electron which is then passed down the electron transport chain via electron carriers. The excited electron is transferred to another chlorophyll molecule in photosystem I creating a proton gradient. The transfer of electron results in the reduction of co-enzyme NADP to NADPH (Starr et al., 2009). The created energy also helps hydrogen ions to move across the thylakoid membrane. Also at the end of the proton gradient, the enzyme ATP synthase converts ADP to ATP by a process called photophosphorylation where the converted light energy will be stored (Starr et a l., 2009). A water molecule is also split though the process of photolysis resulting in an oxygen molecule and allowing the chlorophyll pigment to regain its lost electron. Therefore, at the end of the first cycle the resulting molecules are 3 ATP, 1 oxygen, and 2 NADPH (Starr et al., 2009). The second part of the process is called the light independent reaction and occurs in the stroma within the chloroplasts and is used to take the carbon dioxide molecule and convert it into sugar. Although, it doesn’t need the light, this part of photosynthesis relies on the products ATP and NADPH to drive its process, the Calvin cycle. The enzyme RuBisCO takes the carbon dioxide molecule and uses it to catalyze RuBP (Starr et al., 2009). The carbon dioxide combines with this 5-carbon molecule in a process called carbon fixation and produces 2