This chapter introduces the basic physical principles that underlie photosynthetic energy storage and the current understanding of the structure and function of the photosynthetic apparatus. It talks about how oxygenic photosynthetic organisms, such as plants, use solar energy to synthesize complex carbon compounds. It also explores the essential concepts that provide a foundation for understanding photosynthesis. The chapter also looks at light energy that drives the synthesis of carbohydrates and the generation of oxygen from carbon dioxide and water. It deals with the role of light in photosynthesis, the structure of the photosynthetic apparatus, and the processes that begin with the excitation of chlorophyll by light and culminate in the synthesis of ATP and NADPH.
Chapter
Photosynthesis: The Light Reactions
Chapter
Primary Production Processes
This chapter introduces the major factors that control primary production and how to measure it. Primary production is the starting point of all life in marine systems. Primary producers in the oceans span many orders of magnitude. Production is measured using bottled incubations or, increasingly, from space, using (satellite-borne) ocean colour sensors that detect photosynthetic pigments in surface waters. The conversion of inorganic carbon into biomass, its subsequent sinking to the seabed, and sequestration over thousands of years are fundamental to an understanding of the ocean as a potential sink for increasing levels of atmospheric carbon dioxide. About 55% of the total carbon captured on Earth through the process of photosynthesis and production of biomass takes place in marine systems.
Chapter
Carbohydrates and Carbohydrate Metabolism
Alex White and Helen Burrell
This chapter focuses on carbohydrates, which are molecules composed almost exclusively of carbon, hydrogen, and oxygen. Carbohydrate monomers are called monosaccharides and are found throughout nature. The chapter explains how carbohydrates are synthesized in plants during the process of photosynthesis, with their carbon atoms being obtained from atmospheric carbon dioxide. The chapter considers carbohydrates as the main fuel source in human bodies and they are divided into two groups: simple sugars and complex carbohydrates. Simple sugars like glucose are metabolized directly via glycolysis and the citric acid cycle, whereas complex carbohydrates like starch and glycogen are first broken down into simple sugars.
Chapter
Transport of Oxygen and Carbon Dioxide in Body Fluids
(with an Introduction to Acid–Base Physiology)
This chapter discusses the transport of oxygen and carbon dioxide in body fluids. It also introduces the concept of acid-base physiology and shows how this focuses on the regulation of pH and the functions of respiratory pigments in animals. Haemoglobins, haemocyanins, haemerythrins, and chlorocruorins, also known as the four chemical categories of respiratory pigments, resemble the properties of the enzyme proteins. The chapter mentions the oxygen equilibrium curve as a key tool for understanding the function of a respiratory pigment. It also explores the process of carbon dioxide transport by acknowledging the other chemical forms in which carbon dioxide exists in the blood.
Chapter
Cardiorespiratory Bases for Performance
This chapter provides a background on cardiovascular and respiratory systems from the perspective of the athlete. Their most important function is to deliver oxygen to the exercising muscles and to remove carbon dioxide, while maintaining blood flow to vital organs. The chapter explains how the cardiovascular system matches the blood flow to skeletal muscle to its metabolic rate. It also analyszes two circuits of the cardiovascular system that are arranged both in parallel and in series: pulmonary circuit and systemic circuit. The chapter explains that the pulmonary circuit conducts blood from the right side of the heart to the lungs and back to the left side of the heart. It clarifies how the systemic circuit conducts blood from the left side of the heart to all the tissues in the body and back to the right side of the heart.
Chapter
The respiratory system
This chapter details the principal role of the respiratory system, which is to provide an exchange of gases between the body and the environment. It outlines the functions of the respiratory system, such as its contribution to the maintenance of plasma pH and the production of sound. It also explains how the respiratory system ensures that adequate amounts of oxygen are delivered to tissues and carbon dioxide is efficiently removed when exchanging gases in a variety of environmental challenges. The chapter talks about the paired lungs that sit inside the thorax, which are formed from a series of bifurcations of a single trachea. It details how air enters the lung by a suction pump, wherein inspiration results in an increase in volume and a decrease in pressure inside the lungs.
Chapter
Introduction to Oxygen and Carbon Dioxide Physiology
This chapter introduces oxygen and carbon dioxide physiology. It starts with the properties of gases in gas mixtures and aqueous solutions. The respiratory gases move from place to place principally through the mechanisms of simple diffusion and convection (bulk flow). Simple diffusion is one of the two principal mechanisms of respiratory gas transport, while transport by bulk flow occurs when a gas mixture or an aqueous solution flows and gas molecules in the gas or liquid are carried from place to place by the fluid flow. Additionally, the concept of chemical potential plays a significant role in understanding respiratory gases and gas transport. The chapter also considers the concept of oxygen cascade in line with understanding the transport of O2 from the environment to the mitochondria of an animal.
Chapter
Diving by Marine Mammals
Oxygen, Carbon Dioxide, and Internal Transport AT WORK
This chapter looks into the science of diving by marine mammals by considering the interplay between oxygen, carbon dioxide, and internal transport. Advances in technology have provided new options for getting time and depth information on the swimming of the Weddell seal. The size of a diving mammal's total O2 store is a key determinant of how long the animal can stay submerged. Moreover, circulation holds a special place in the chronicles of diving physiology because the very first physiological observations on diving were measures of heart rates. The chapter also looks into the notion of metabolism during dives and the aetiology of decompression sickness.
Chapter
Water Balance of Plants
This chapter examines the mechanisms and driving forces operating on water transport within the plant and between the plant and its environment. To meet the contradictory demands of maximizing carbon dioxide uptake while limiting water loss, plants have evolved to control water loss from leaves, and to replace the water lost to the atmosphere with water drawn from the soil. The chapter thus begins by focusing on water in the soil. It then considers how water moves from the soil into the roots and from the roots up through specialized transport cells to the leaves from which water is lost to the atmosphere. The chapter goes on to look at the ways in which the leaf can control the loss of water, as well as the entry of CO2, by regulating the opening and closing of stomata, the small openings through which the major water loss occurs. Finally, the chapter summarises the soil-plant-atmosphere continuum.
Chapter
Transport in respiratory systems and acid–base balance
This chapter reviews the transport of the respiratory gases in the respiratory systems of animals. Two major respiratory pigments are found in the blood: the copper-based haemocyanin and the iron-based haemoglobin. The maximum concentration of oxygen in the blood when the blood pigment is fully saturated is the oxygen-carrying capacity. Meanwhile, carbon dioxide is carried mostly as bicarbonate ions in the plasma of vertebrates, some as carbamino compounds, after it combines with amino acid residues on respiratory pigments, and a small amount is in solution. The chapter then looks at the acid–base balance of animals, before considering the transport of metabolic substrates in the blood to the metabolizing cells.
Chapter
Water Balance of Plants
This chapter examines the mechanisms and driving forces operating on water transport within the plant and between the plant and its environment. To meet the contradictory demands of maximizing carbon dioxide uptake while limiting water loss, plants have evolved to control water loss from leaves, and to replace the water lost to the atmosphere with water drawn from the soil. The chapter thus begins by focusing on water in the soil. It then considers how water moves from the soil into the roots and from the roots up through specialized transport cells to the leaves from which water is lost to the atmosphere. Finally, the chapter looks at the ways in which the leaf can control the loss of water, as well as the entry of CO2, by regulating the opening and closing of stomata, the small openings through which the major water loss occurs.
Chapter
The biochemistry of zinc
This chapter takes a closer look at zinc, the most abundant transition metal in all living organisms next to iron. It provides examples for the following five main categories of proteins in which zinc attains a structural function and/or mediates catalytic processes: Enzymatic activity in hydrolytic processes; substrate activation for oxidative detoxification; interconversion between carbon dioxide and hydrogencarbonate; transcription of the genetic information contained in deoxyribonucleic acid (DNA) for protein synthesis; and demethylation — and thus repair — of DNA damaged by methylation. The chapter addresses questions on how zinc ions mediate the breakdown of proteins in our food, making available amino acids for resorption and thus usage in the synthesis of our body's own proteins; how ethanol is converted to acetaldehyde; how metabolically released carbon dioxide is processed for transport into the lungs; and how the small proteins called thioneins contribute to controlling zinc homeostasis in the body.
Chapter
Metal– and metalloid–carbon bonds
This chapter discusses the role of the transition metal-carbon bond in the activation of substrates such as carbon oxide, carbon dioxide, nitrogen, methane, alkenes, and alkynes, focusing in part on selected examples of metalloenzymes. It looks at the processing of organometal and -metalloid compounds in biogeochemical cycles. The chapter also explores the special role of adenosyl- and methyl-cobalamin (vitamin B12), the latter in the frame of the broad range of physiologically important methyl transfer reactions. Furthermore, it briefly sets out the physiological implications of the selenium-carbon bond. Lastly, the chapter addresses the biogeochemical making and breaking of the metal and -metalloid carbon bond in poisoning by, and detoxification of, mercury, lead, and arsenic.
