A-Level Biology - A-Level Biology - Antibodies - Structure & Function in the Immune System (2026/27 exams)

⭐️ Check out our website https://www.cognito.org/ ⭐️ *** WHAT'S COVERED *** 1. The structure of antibodies (immunoglobulins) * The Y-shaped structure composed of four polypeptide chains (2 heavy and 2 light). * The role of disulfide bridges in holding the chains together. * The different regions of an antibody: constant region, variable region, and hinge region. * How the variable region binds to specific antigens. 2. The functions of antibodies in the immune system * Formation of the antigen-antibody complex. * Agglutination: clumping pathogens together for easier phagocytosis. * Opsonisation: tagging pathogens to make them more recognisable to phagocytes. * Neutralisation: blocking the binding sites of pathogens to prevent them from infecting host cells. * Anti-toxins: neutralising harmful toxins released by pathogens. *** EXAM BOARD SPECIFIC INFO *** AQA - You don't need to know about the hinge region of the antibody, or about opsonins OCR - Everything is relevant to your course! CIE - You don't need to know about opsonins *** CHAPTERS *** 0:00 Introduction to Antibodies 0:19 Structure of Antibodies 2:01 Functions of Antibodies in the Immune System 2:20 Agglutination of Pathogens 2:42 Tagging Pathogens (Opsonisation) 2:54 Neutralisation of Pathogens 3:15 Anti-Toxin Function *** PLAYLISTS *** https://youtube.com/playlist?list=PLidqqIGKox7VzYfPIVt8T09xOLNcolCe4&si=8JmDajxjtba6rdc3 https://youtube.com/playlist?list=PLidqqIGKox7UZ3mWhbHv2aA_1vnbsfRPq&si=q3hEKdA4v7kbfwMe https://www.youtube.com/playlist?list=PLidqqIGKox7UTimdJ3eFcnt6xL9GUt2a6 https://youtube.com/playlist?list=PLidqqIGKox7XPh1QacLRiKto_UlnRIEVh&si=orIUwL3o2jOoiYjT https://youtube.com/playlist?list=PLidqqIGKox7X5UFT-expKIuR-i-BN3Q1g&si=DcihOwUkd9oWbbdp https://youtube.com/playlist?list=PLidqqIGKox7WeOKVGHxcd69kKqtwrKl8W&si=Y8MsO-FK948jnxpS https://youtube.com/playlist?list=PLidqqIGKox7UVC-8WC9djoeBzwxPeXph7&si=-7i5Iq7yOeJrhtu6 https://youtube.com/playlist?list=PLidqqIGKox7VKJD2WxRhoKaI6JGLVean8&si=NH_Q1ujhVgACM2FU #ALevel #Biology #study #revision #school #exam #AQA #OCR #Edexcel