Adenosine Triphosphate (ATP)
Adenosine triphosphate (ATP) is a molecule that serves as the primary energy currency in living organisms. It is composed of an adenosine molecule and three phosphate groups, which store and release energy through the breaking and formation of chemical bonds. ATP is essential for various cellular processes, including muscle contraction, nerve impulse transmission, and biosynthesis.
5 Key excerpts on "Adenosine Triphosphate (ATP)"
eBook - ePub- David A Bender, Shauna M C Cunningham(Authors)
- 2021(Publication Date)
- CRC Press(Publisher)
...chapter three The Role of ATP in Metabolism Adenosine triphosphate (ATP) acts as the central link between energy-yielding metabolic pathways and energy expenditure in physical and chemical work. The oxidation of metabolic fuels is linked to the phosphorylation of adenosine diphosphate (ADP) to ATP, while the expenditure of metabolic energy for the synthesis of body constituents, transport of compounds across cell membranes and the contraction of muscle results in the hydrolysis of ATP to yield ADP and phosphate ions. The total body content of ATP + ADP is under 350 mmol (about 10 g), but the amount of ATP synthesized and used each day is about 100 mol (about 70 kg), an amount equal to body weight. Objectives After reading this chapter, you should be able to: • explain how endothermic reactions can be linked to the overall hydrolysis of ATP → ADP and phosphate • describe how compounds can be transported across cell membranes against a concentration gradient and explain the roles of ATP and proton gradients in active transport • describe the role of ATP in muscle contraction and the role of creatine phosphate as a phosphagen • describe the structure and functions of the mitochondrion and explain the processes involved in the mitochondrial electron transport chain and oxidative phosphorylation, explain how substrate oxidation is regulated by the availability of ADP, and how respiratory poisons and uncouplers act. 3.1 Adenine Nucleotides Nucleotides consist of a purine or pyrimidine base linked to the 5-carbon sugar ribose. The base plus sugar is a nucleoside; in a nucleotide the sugar is phosphorylated. Nucleotides may be mono-, di- or triphosphates. Figure 3.1 The adenine nucleotides (the box shows the structures of adenine, guanine and uracil; guanine and uracil form a similar series of nucleotides). Figure 3.1 shows the nucleotides formed from the purine adenine – the adenine nucleotides, adenosine monophosphate (AMP), ADP and ATP...
eBook - ePubNutrition
CHEMISTRY AND BIOLOGY, SECOND EDITION
- Julian E. Spallholz, Mallory Boylan, Judy A. Driskell(Authors)
- 2018(Publication Date)
- CRC Press(Publisher)
...Cellular Metabolism CHAPTER 10 Body Energy Energy is the capacity to do work. In nutrition, energy expenditure refers to the manner in which the body utilizes the energy obtained via the metabolism of the energy-yielding nutrients carbohydrates, lipids, and proteins. The body is about 40% efficient in capturing the energy from the catabolism of the energy-yielding nutrients. Food energy must be supplied regularly to individuals for their survival and is necessary for the maintenance of human life. The cells of the body do not use the energy-yielding nutrients in the diet for their immediate energy supply. Rather, adenosine triphosphate (ATP), a high-energy compound, is the fuel for energyrequiring reactions. The potential energy stored in ATP molecules provide the chemical energy for biological work. Energy released during ATP hydrolysis activates other energy-requiring molecules. ATP is the “energy currency” of the cell. Slightly over 85 grams of ATP are present in the adult body at any one time. AEROBIC AND ANAEROBIC ENERGY RELEASE Aerobic means oxygen-requiring, while anaerobic reactions do not require oxygen. Energy (ATP) can be released by the cell both aerobically and anaerobically. Energy produced anaerobically can be immediately utilized by the cell and is important in such activities as sprinting and surviving underwater submersion. ENERGY RESERVOIR Creatine phosphate, a high-energy compound, serves as an energy reservoir for the body. Anaerobic hydrolysis of creatine phosphate provides energy for the resynthesis of ATP from adenosine diphosphate (ADP) and inorganic phosphate (P i) forming creatine plus inorganic phosphate (P i). Both of the these reactions are reversible. The cells of our bodies, particularly those of skeletal muscles, are able to store creatine phosphate in larger quantities than ATP. All-out exercise, such as swimming or running, can be maintained for about 6 to 8 seconds utilizing the energy released from creatine phosphate and ATP...
eBook - ePub- Jennifer Guercio, Michael D'Alessio, Lauren Gross(Authors)
- 2013(Publication Date)
- Research & Education Association(Publisher)
...energy. A + B + Energy → AB i. In anabolic reactions, reactant(s) are joined together to produce product(s) containing more energy. ii. The free energy required by anabolic reactions is often provided by ATP produced in catabolic reactions. 3. Adenosine triphosphate (ATP) carries energy in its high energy phosphate bonds. i. ATP is formed from adenosine diphosphate (ADP) and inorganic phosphate. ADP + Pi + Energy → ATP ii. Conversely, when ATP is broken down into ADP and Pi via hydrolysis, energy is released (exergonic) that can be used in endergonic reactions. iii. In addition, ATP can donate one of its phosphate groups to a molecule, such as a substrate or a protein, to energize it or cause it to change its shape. 4. Living systems require a consistent input of free energy and an ordered system. i. This free energy input allows for a system’s order to be maintained. ii. If either order in the system or free energy flow were to occur, death can result. iii. Biological processes are in place to help offset increased disorder and entropy and to help maintain order within a system; therefore, energy input into the system. must exceed the loss of free energy in order to maintain order and to power cellular processes. iv. Energy storage and growth can result from excess acquired free energy beyond the required energy necessary for maintenance and order within a system. v. Changes in free energy can affect population size and cause disruptions to an ecosystem. 5. Metabolism —the totality of all chemical reactions that occur within an organism. i. Reproduction and rearing of offspring require free energy beyond what is normally required for the maintenance and growth of the organism. Energy availability can vary, and different organisms utilize a variety of reproductive strategies as a consequence...
- Karen Birch, Keith George, Don McLaren(Authors)
- 2004(Publication Date)
- Routledge(Publisher)
...2 Fig. 2 Schematic of (a) the structure and, (b) hydrolysis of ATP.). When a phosphate is removed from ATP, the energy produced provides the currency to enable muscles to move, molecules to be synthesized or to be transported against a concentration gradient or to be excreted. Indeed, any energy requiring processes invariably uses ATP as the prime source of energy. ATP is hydrolyzed by enzymes called ATPases which result in the formation of adenosine diphosphate (ADP) and inorganic phosphate (Pi). The equation can be represented as follows: adenosine − P − P − P ↔ ↑ ATPase adenosine − P − P − P i + energy (37 kJ) The amount of ATP in muscle is rather small, with the concentration being approximately 20–30 mM kg −1 of dry muscle. This amount of ATP in muscle has been estimated to be sufficient to fuel around 3–5 s of maximal effort if ATP was the sole energy source. Clearly this is not the case, because maximal efforts last longer, and so the restoration of ATP must occur. Creatine phosphate The other immediate source of energy for high intensity exercise is that of creatine phosphate or phosphocreatine (PCr). PCr is also a high-energy phosphate in which a single phosphate molecule is attached to a molecule of creatine. Hydrolysis of PCr is brought about by the enzyme creatine kinase (CK) as follows: The reaction above is linked to the re-forming (rephosphorylation) of ATP from ADP: The enzyme CK exists in a number of isoenzymes, which have the same formula but possess different rates for the above reaction. The two best examples from a muscle and exercise context are CK mm (the form of creatine kinase found at the muscle crossbridge) and CK mito (the mitochondrial form of creatine kinase). Whereas CK mm favors the above reaction from left to right, the isoform CK mito favors the reaction from right to left...
- John Allen(Author)
- 2013(Publication Date)
- Research & Education Association(Publisher)
...You should be able to identify the reactants, products and/or the basic functions of aerobic and anaerobic cellular respiration. 9. You should be able to connect the role of adenosine triphosphate (ATP) to energy transfers within the cell. 10. You should be able to explain the properties of water at a conceptual level. 11. You should be able to explain how the properties make water essential for life on Earth. Standards The following standards are assessed on the Florida Biology 1 End-of-Course Assessment either directly or indirectly: SC.912.L.18.1 Describe the basic molecular structures and primary functions of the four major categories of biological macromolecules. SC.912.L.18.7 Identify the reactants, products, and basic functions of photosynthesis. SC.912.L.18.8 Identify the reactants, products, and basic functions of aerobic and anaerobic cellular respiration. SC.912.L.18.9 Explain the interrelated nature of photosynthesis and cellular respiration. SC.912.L.18.10 Connect the role of adenosine triphosphate (ATP) to energy transfers within a cell. SC.912.L.18.11 Explain the role of enzymes as catalysts that lower the activation energy of biochemical reactions. Identify factors, such as pH and temperature, and their effect on enzyme activity. SC.912.L.18.12 Discuss the special properties of water that contribute to Earth’s suitability as an environment for life: cohesive behavior, ability to moderate temperature, expansion upon freezing, and versatility as a solvent. Basics of Biochemistry The atom is the building block of all matter. An atom consists of the subatomic particles protons, neutrons, and electrons. The nucleus of an atom contains protons, which have a positive charge, and neutrons, which have a neutral charge. Negatively charged electrons are outside the nucleus...
