TAILIEUCHUNG - Lecture Principles of biochemistry - Chapter 5 (part 1): Enzymes - Introduction

After studying this chapter you will be able to: Define Catalyst and know the properties of a catalyst; know the 6 classes of enzymes and there functions, be able to classify a specific enzyme if given the reaction; Define Coenzyme, apoenzyme, holoenzyme;. | Chapter 5 (part 1) Enzymes: Introduction Catalyst substance that increase rates of a chemical reaction does not effect equilibrium remain unchanged in overall process reactants bind to catalyst, products are released Catalysts increase product formation by (1) lowering the energy barrier (activation energy) for the product to form (2) increases the favorable orientation of colliding reactant molecules for product formation to be successful (stabilize transition state intermediate) Catalytic Power Enzymes can accelerate reactions as much as 1016 over uncatalyzed rates! Urease is a good example: Catalyzed rate: 3x104/sec Uncatalyzed rate: 3x10 -10/sec Ratio is 1x1014 ! Specificity Enzymes selectively recognize proper substrates over other molecules Enzymes produce products in very high yields - often much greater than 95% Specificity is controlled by structure - the unique fit of substrate with enzyme controls the selectivity for substrate and the product yield Classes of enzymes Oxidoreductases = catalyze oxidation-reduction reactions (NADH) Transferases = catalyze transfer of functional groups from one molecule to another. Hydrolases = catalyze hydrolytic cleavage Lyases = catalyze removal of a group from or addition of a group to a double bond, or other cleavages involving electron rearrangement. Isomerases = catalyze intramolecular rearrangement. Ligases = catalyze reactions in which two molecules are joined. Enzymes named for the substrates and type of reaction Co-enzymes Non-protein molecules that help enzymes function Associate with active site of enzyme Enzyme + Co-enzyme = holoenzyme Enzyme alone = apoenzyme Organic co-enzymes – thiamin, riboflavin, niacin, biotin Inorganic co-enzymes – Mg ++, Fe++, Zn++, Mn++ Kinetics study of reaction rate determines number of steps involved determines mechanism of reaction identifies “rate-limiting” step

TAILIEUCHUNG - Chia sẻ tài liệu không giới hạn
Địa chỉ : 444 Hoang Hoa Tham, Hanoi, Viet Nam
Website : tailieuchung.com
Email : tailieuchung20@gmail.com
Tailieuchung.com là thư viện tài liệu trực tuyến, nơi chia sẽ trao đổi hàng triệu tài liệu như luận văn đồ án, sách, giáo trình, đề thi.
Chúng tôi không chịu trách nhiệm liên quan đến các vấn đề bản quyền nội dung tài liệu được thành viên tự nguyện đăng tải lên, nếu phát hiện thấy tài liệu xấu hoặc tài liệu có bản quyền xin hãy email cho chúng tôi.
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.