Welcome to Biology Notes Online! We are the BNO Team, dedicated to providing high-quality, accessible biology study notes for students and teachers alike. Our goal is to simplify complex biological concepts and present them in an easy-to-understand format, entirely free of charge. Whether you're preparing for exams, teaching a class, or simply passionate about biology, our comprehensive notes are designed to support your learning and teaching journey.
Complement System Definition The complement system, also known as the complement cascade, is a component of the immune system that boosts the ability of antibodies and phagocytic cells to eliminate germs and damaged cells from an organism, stimulate inflammation, and assault the cell membrane of a pathogen. Properties of Complement Complement demonstrates the following attributes: … Read more
The Membrane-Attack Complex Can Lyse a Broad Spectrum of Cells Cleavage Products of Complement Components Mediate Inflammation C3b and C4b Binding Facilitates Opsonization The Complement System Also Neutralizes Viral Infectivity The Complement System Clears Immune Complexes from Circulation Complement Deficiencies C1q, C1r, C1s, C4, and C2 Deficiencies C3 deficiencies Homozygous deficiencies Congenital deficiencies The majority … Read more
The classical pathway is a key immune system mechanism that plays an important role in defending the body from foreign invaders. It consists of a series of sequential interactions among complement components that result in the killing of target cells via a process known as cell lysis. The presence of an antibody attached to an antigen, … Read more
What is Alternative pathway of the complement system ? Activators of the alternative pathway Activators of the alternative pathway of complement activation include Steps of activation of alternative pathway Four serum proteins comprise the initial component of the alternative pathway: C3b, factor B, factor D, and properdin. 1. C3bB complex Formation 2. C3bB Cleavage 3. … Read more
An Overview of Complement System What is Lectin Pathway of Complement Activation? Components of Lectin Pathway 1. Mannose-binding lectin Structural subunits of mannan-binding lectin (MBL) and ficolins 2. MBL serum levels and MBL2 gene polymorphisms 3. Ficolins Ficolin-1 Ficolin-2 Ficolin-3 4. MBL-associated serine proteases Steps, Mechanism, Process of Lectin Pathway The lectin pathway, also known … Read more
1. The SXY–CIITA Regulatory System 2. TNF- And IFN-Induced Expression Of Mhc Class I 3. Expression Of Mhc Class Ib Genes 4. Other Regulatory Pathways Governing Mhc Class II Gene Expression
What is HLA Complex? What is H-2 Complex? Detailed Organization Of The H-2 Complex 1. Murine MHC Class I Genes 2. Murine 2-Microglobulin Gene 3. Murine MHC Class Ib Genes 4. Murine MHC Class II Genes 5. Murine MHC Class IIb Genes 6. Murine Non-MHC Genes in the MHC 7. Murine MHC Class III Genes … Read more
Antigen-Antibody (Ag-Ab) Interaction refers to the biochemical reaction that occurs between antibodies and specific antigens when they come into close proximity, typically within a distance of several nanometers. This interaction plays a critical role in the immune response against foreign substances and pathogens in the body. The binding of antibodies to specific antigens is facilitated … Read more
What is Antigen? Antigen Definition An antigen is a foreign molecule or substance that triggers an immune response in the body, leading to the production of antibodies. or An antigen is a substance that can stimulate an immune response in the body. It can be a molecule or a part of a molecule, such as … Read more
Antigen Presentation Definition Antigen-Presenting Cells Definition Types of Antigen-Presenting Cells Antigen-presenting cells fall into two categories: Antigen-presenting cells that contain MHC class II molecules, co-stimulatory molecules, and pattern recognition receptors are often referred to be “professional.” Non-professional APCs express molecules of MHC class I. 1. Professional Antigen-Presenting Cells a. Macrophages Activation of Macrophages For macrophages … Read more
⚠️
Click on your ad blocker icon in your browser's toolbar
Select "Pause" or "Disable" for this website
Refresh the page if it doesn't automatically reload
16 min read 
