Unit 5: Respiration, Internal Environment, Coordination and Gene Technology

(i) understand the overall reaction of aerobic respiration as splitting of the respiratory substrate to release carbon dioxide as a waste product and reuniting hydrogen with atmospheric oxygen with the release of large amounts of energy (ii) understand that respiration is a stepped process, with each step controlled and catalysed by a specific intracellular enzyme Names of specific enzymes are not required.

Understand the roles of glycolysis in aerobic and anaerobic respiration, including the phosphorylation of hexoses, the production of ATP by substrate level phosphorylation, reduced coenzyme, pyruvate and lactate Details of intermediate stages and compounds are not required.

Understand the role of the link reaction and the Krebs cycle in the complete oxidation of glucose and formation of carbon dioxide (CO2) by decarboxylation, ATP by substrate level phosphorylation, reduced NAD and reduced FAD by dehydrogenation (names of other compounds are not required) and that these steps take place in mitochondria, unlike glycolysis which occurs in the cytoplasm

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

Understand what happens to lactate after a period of anaerobic respiration in animals

Understand what is meant by 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 (such as germinating seeds or small invertebrates).

Know the way in which muscles, tendons, the skeleton and ligaments interact to enable movement, including antagonistic muscle pairs, extensors and flexors

(i) know the structure of a mammalian skeletal muscle fibre (ii) understand the structural and physiological differences between fast and slow twitch muscle fibres

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

(i) know the myogenic nature of cardiac muscle (ii) understand how the normal electrical activity of the heart coordinates the heartbeat, including the roles of the sinoatrial node (SAN), the atrioventricular node (AVN), the bundle of His and the Purkyne fibres (iii) understand how the use of electrocardiograms (ECGs) can aid in the diagnosis of abnormal heart rhythms

(i) be able to calculate cardiac output (ii) understand how variations in ventilation and cardiac output enable rapid delivery of oxygen to tissues and the removal of carbon dioxide from them, including how the heart rate and ventilation rate are controlled and the roles of 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.

(i) understand what is meant by the terms negative feedback and positive feedback control (ii) understand the principle of negative feedback in maintaining systems within narrow limits

Understand what is meant by the term homeostasis and its importance in maintaining the body in a state of dynamic equilibrium during exercise, including the role of the hypothalamus in thermoregulation

Know the gross and microscopic structure of the mammalian kidney

Understand how urea is produced in the liver from excess amino acids (details of the ornithine cycle are not required) and how it is removed from the bloodstream by ultrafiltration

Understand how solutes are selectively reabsorbed in the proximal tubule and how the loop of Henle acts as a countercurrent multiplier to increase the reabsorption of water

Understand how the pituitary gland and osmoreceptors in the hypothalamus, combined with the action of antidiuretic hormone (ADH), bring about negative feedback control of mammalian plasma concentration and blood volume

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

8.1Neurone structure and function

Know the structure and function of sensory, relay and motor neurones, including Schwann cells and myelination

8.2Nervous system control of effectors

Understand how the nervous system of organisms can cause effectors to respond to a stimulus

8.3Spinal reflex arc

Know the structure and function of a spinal reflex arc, including grey matter and white matter of the spinal cord

8.4Action potential conduction

Understand how a nerve impulse (action potential) is conducted along an axon, including changes in membrane permeability to sodium and potassium ions

8.5Saltatory conduction

Understand the role of myelination in saltatory conduction

8.6Synapses, neurotransmitters and pupil response

(i) know the structure and function of synapses in nerve impulse transmission, including the role of neurotransmitters and acetylcholine (ii) understand how the pupil dilates and contracts

8.7Drugs and nerve impulse transmission

Understand how the effects of drugs can be caused by their influence on nerve impulse transmission, illustrated by nicotine, lidocaine and cobra venom alpha toxin, the use of L-DOPA in the treatment of Parkinson’s disease and the action of MDMA (ecstasy)

8.8Rod cells and stimulus detection

Understand how the nervous systems of organisms can detect stimuli with reference to rods in the retina of mammals, the roles of rhodopsin, opsin, retinal, sodium ions, cation channels and hyperpolarisation of rod cells in forming action potentials in the optic neurones

8.9Habituation

Understand what is meant by the term habituation

8.10Central and peripheral nervous systems

Know that the mammalian nervous system consists of the central and peripheral nervous systems

8.11Plant responses: phytochrome, auxin and gibberellins

Understand how phytochrome, auxin (IAA) and gibberellins bring about responses in plants, including their effects on transcription

8.12Core Practical 18 - amylase in germinating cereal grains

CORE PRACTICAL 18 Investigate the production of amylase in germinating cereal grains.

8.13Coordination by nervous and hormonal control

Understand how coordination in animals is brought about through nervous and hormonal control

8.14Human brain regions

Know the location and main functions of the cerebral hemispheres, hypothalamus, pituitary gland, cerebellum and medulla oblongata of the human brain

8.15Medical imaging of the brain

Understand how magnetic resonance imaging (MRI), functional magnetic resonance imaging (fMRI), positron emission tomography (PET) and computed tomography (CT) are used in medical diagnosis and the investigation of brain structure and function

8.16Brain chemicals, ill health and drugs

Understand how imbalances in certain naturally-occurring brain chemicals can contribute to ill health, including dopamine in Parkinson’s disease and serotonin in depression, and to the development of new drugs

8.17Drug production using GM organisms

Know how drugs can be produced using genetically modified organisms (plants, animals and microorganisms)

8.18Recombinant DNA production

Understand how recombinant DNA can be produced, including the roles of restriction endonucleases and DNA ligase

8.19Inserting recombinant DNA into cells

Understand how recombinant DNA can be inserted into other cells

8.20Microarrays and active genes

Know how microarrays can be used to identify active genes

8.21Bioinformatics

Understand what is meant by the term bioinformatics

8.22Risks and benefits of GM organisms

Understand the risks and benefits associated with the use of genetically modified organisms