Respiration, Muscles and the Internal Environment

Respiration Overview and GlycolysisSign up

understand the overall reaction of aerobic respiration: splitting of respiratory substrate to release CO₂ and reuniting hydrogen with atmospheric oxygen, releasing large amounts of energy · understand that respiration is a stepped process, each step controlled and catalysed by a specific intracellular enzyme (names of enzymes not required) · understand the role of glycolysis in aerobic and anaerobic respiration: phosphorylation of hexoses, ATP production by substrate-level phosphorylation, reduced coenzyme, pyruvate and lactate (intermediate compound names not required)

The Link Reaction and the Krebs CycleSign up

understand the role of the link reaction and the Krebs cycle in the complete oxidation of glucose, formation of CO₂ by decarboxylation, ATP by substrate-level phosphorylation, and reduced NAD/FAD by dehydrogenation (other compound names not required); locate these steps in mitochondria vs glycolysis in the cytoplasm

Oxidative Phosphorylation and ATP SynthaseSign up

understand how ATP is synthesised by oxidative phosphorylation associated with the electron transport chain in mitochondria, including the role of chemiosmosis and ATP synthase

Anaerobic Respiration, RQ and RespirometrySign up

understand what happens to lactate after anaerobic respiration in animals · understand the term respiratory quotient (RQ) · CORE PRACTICAL 15: use an artificial hydrogen carrier (redox indicator) to investigate respiration in yeast · CORE PRACTICAL 16: use a simple respirometer to determine the rate of respiration and RQ of a suitable material (e.g. germinating seeds or small invertebrates)

Muscles and the SkeletonSign up

know how muscles, tendons, the skeleton and ligaments interact to enable movement, including antagonistic muscle pairs, extensors and flexors · know the structure of a mammalian skeletal muscle fibre; differences between fast and slow twitch fibres

Sliding Filament Theory of Muscle ContractionSign up

understand the process of skeletal muscle contraction in terms of the sliding filament theory, including the roles of actin, myosin, troponin, tropomyosin, calcium ions (Ca²⁺), ATP and ATPase

Cardiac Muscle, ECGs and Cardiac OutputSign up

know the myogenic nature of cardiac muscle · understand how the normal electrical activity of the heart coordinates the heartbeat (SAN, AVN, bundle of His, Purkyne fibres) · understand how ECGs can aid in the diagnosis of abnormal heart rhythms · calculate cardiac output

Ventilation, Exercise and AdrenalineSign up

understand how variations in ventilation and cardiac output enable rapid O₂ delivery and CO₂ removal, including control by the cardiovascular control centre and the ventilation centre in the medulla oblongata · understand the role of adrenaline in the fight-or-flight response · CORE PRACTICAL 17: investigate the effects of exercise on tidal volume, breathing rate, respiratory minute ventilation, and oxygen consumption using data from spirometer traces

Feedback Control and HomeostasisSign up

understand negative feedback and positive feedback control · understand the principle of negative feedback in maintaining systems within narrow limits · understand homeostasis and its importance in maintaining dynamic equilibrium during exercise, including the role of the hypothalamus in thermoregulation

The Mammalian Kidney, Urea and OsmoregulationSign up

know the gross and microscopic structure of the mammalian kidney · understand how urea is produced from excess amino acids in the liver (ornithine cycle detail not required) and removed by ultrafiltration · understand selective reabsorption in the proximal tubule and how the loop of Henle acts as a countercurrent multiplier to increase water reabsorption · understand how the pituitary, osmoreceptors in the hypothalamus, and ADH bring about negative feedback control of plasma concentration and blood volume

Hormones and Gene Expression ControlSign up

understand how genes can be switched on and off by DNA transcription factors, including the role of peptide hormones acting extracellularly vs steroid hormones acting intracellularly