IB Biology C - Interaction and Interdependence

C1.1.1 Enzymes as catalysts

C1.1.2 Role of enzymes in metabolism

C1.1.3 Anabolic and catabolic reactions

C1.1.4 Enzymes as globular proteins with an active site for catalysis

C1.1.5 Interactions between substrate and active site to allow induced-fit binding

C1.1.6 Role of molecular motion and substrate-active site collisions in enzyme catalysis

C1.1.7 The structure of the active site, enzyme–substrate specificity and denaturation

C1.1.8 Effects of temperature, pH and substrate concentration on the rate of enzyme activity

C1.1.9 Measurements in enzyme-catalysed reactions

C1.1.10 Effect of enzymes on activation energy

C1.1.11 Intracellular and extracellular enzyme-catalysed reactions (HL)

C1.1.12 Generation of heat energy by the reactions of metabolism (HL)

C1.1.13 Cyclical and linear pathways in metabolism (HL)

C1.1.14 Allosteric sites and non-competitive inhibition (HL)

C1.1.15 Competitive inhibition (HL)

C1.1.16 Regulation of metabolic pathways by feedback inhibition (HL)

C1.1.17 Mechanism-based inhibition (HL)

C1.2.1 ATP as the molecule that distributes energy within cells

C1.2.2 Life processes within cells that ATP supplies with energy

C1.2.3 Energy transfers during interconversions between ATP and ADP

C1.2.4 Cell respiration

C1.2.5 Differences between anaerobic and aerobic cell respiration in humans

C1.2.6 Variables affecting the rate of cell respiration

C1.2.7 Role of NAD as a carrier of hydrogen (HL)

C1.2.8 Conversion of glucose to pyruvate (HL)

C1.2.9 Conversion of pyruvate to lactate (HL)

C1.2.10 Anaerobic cell respiration in yeast and its use in brewing and baking (HL)

C1.2.11 Oxidation and decarboxylation of pyruvate (HL)

C1.2.12 Oxidation and decarboxylation of acetyl groups in the Krebs cycle (HL)

C1.2.13 Transfer of energy by reduced NAD (HL)

C1.2.14 Generation of a proton gradient (HL)

C1.2.15 Chemiosmosis and the synthesis of ATP in the mitochondrion (HL)

C1.2.16 Role of oxygen as terminal electron acceptor in aerobic cell respiration (HL)

C1.2.17 Differences between lipids and carbohydrates as respiratory substrates (HL)

C1.3.1 Transformation of light energy to chemical energy

C1.3.2 Conversion of carbon dioxide to glucose in photosynthesis

C1.3.3 Oxygen as a by-product of photosynthesis

C1.3.4 Separation and identification of photosynthetic pigments by chromatography

C1.3.5 Absorption of specific wavelengths of light by photosynthetic pigments

C1.3.6 Similarities and differences of absorption and action spectra

C1.3.7 The effects of limiting factors on the rate of photosynthesis

C1.3.8 Carbon dioxide enrichment experiments

C1.3.9 Photosystems (HL)

C1.3.10 Advantages of the structured array of different types of pigment molecules (HL)

C1.3.11 Generation of oxygen by the photolysis of water in photosystem II (HL)

C1.3.12 ATP production by chemiosmosis in thylakoids (HL)

C1.3.13 Reduction of NADP by photosystem I (HL)

C1.3.14 Thylakoids as systems for performing the light-dependent photosynthesis reactions (HL)

C1.3.15 Carbon fixation by Rubisco (HL)

C1.3.16 Synthesis of triose phosphate using reduced NADP and ATP (HL)

C1.3.17 Regeneration of RuBP in the Calvin cycle using ATP (HL)

C1.3.18 Synthesis of carbohydrates, amino acids and other carbon compounds (HL)

C1.3.19 Interdependence of the light-dependent and light-independent reactions (HL)

C2.1.1 Receptors

C2.1.2 Cell signalling by bacteria in quorum sensing

C2.1.3 Hormones, neurotransmitters, cytokines and calcium ions

C2.1.4 Chemical diversity of hormones and neurotransmitters

C2.1.5 Localized and distant effects of signalling molecules

C2.1.6 Transmembrane receptors VS Intracellular receptors

C2.1.7 Initiation of signal transduction pathways by receptors

C2.1.8 Transmembrane receptors for neurotransmitters and changes to membrane potential

C2.1.9 Transmembrane receptors that activate G proteins

C2.1.10 Mechanism of action of epinephrine (adrenaline) receptors

C2.1.11 Transmembrane receptors with tyrosine kinase activity

C2.1.12 Intracellular receptors that affect gene expression

C2.1.13 Effects of the hormones oestradiol and progesterone on target cells

C2.1.14 Regulation of cell signalling pathways by positive and negative feedback

C2.2.1 Neurons as cells within the nervous system that carry electrical impulses

C2.2.2 Generation of the resting potential by pumping

C2.2.3 Nerve impulses as action potentials that are propagated along nerve fibres

C2.2.4 Variation in the speed of nerve impulses

C2.2.5 Synapses as junctions between neurons and between neurons and effector cells

C2.2.6 Release of neurotransmitters from a presynaptic membrane

C2.2.7 Generation of an excitatory postsynaptic potential

C2.2.8 Depolarization and repolarization during action potentials (HL)

C2.2.9 Propagation of an action potential along a nerve fibre/axon (HL)

C2.2.10 Oscilloscope traces showing resting potentials and action potentials (HL)

C2.2.11 Saltatory conduction in myelinated fibres to achieve faster impulses (HL)

C2.2.12 Effects of exogenous chemicals on synaptic transmission (HL)

C2.2.13 Inhibitory neurotransmitters and generation of inhibitory postsynaptic potentials (HL)

C2.2.14 Summation of the effects of excitatory and inhibitory neurotransmitters (HL)

C2.2.15 Perception of pain by neurons with free nerve endings in the skin (HL)

C2.2.16 Consciousness (HL)

C3.1.1 System integration

C3.1.2 Cells, tissues, organs and body systems

C3.1.3 Integration of organs in animal bodies

C3.1.4 The brain as a central information integration organ

C3.1.5 The spinal cord as an integrating centre for unconscious processes

C3.1.6 Input to the spinal cord and cerebral hemispheres through sensory neurons

C3.1.7 Output from the cerebral hemispheres to muscles through motor neurons

C3.1.8 Nerves as bundles of nerve fibres of both sensory and motor neurons

C3.1.9 Pain reflex arcs

C3.1.10 Role of the cerebellum in coordinating skeletal muscle contraction and balance

C3.1.11 Modulation of sleep patterns by melatonin secretion as a part of circadian rhythms

C3.1.12 Epinephrine (adrenaline) secretion by the adrenal glands

C3.1.13 Control of the endocrine system

C3.1.14 Feedback control of heart rate

C3.1.15 Feedback control of ventilation rate

C3.1.16 Control of peristalsis in the digestive system

C3.1.17 Observations of tropic responses in seedlings (HL)

C3.1.18 Positive phototropism (HL)

C3.1.19 Phytohormones (HL)

C3.1.20 Auxin efflux carriers (HL)

C3.1.21 Promotion of cell growth by auxin (HL)

C3.1.22 Interactions between auxin and cytokinin (HL)

C3.1.23 Positive feedback in fruit ripening and ethylene production (HL)

C3.2.1 Pathogens as the cause of infectious diseases

C3.2.2 Skin and mucous membranes as a primary defence

C3.2.3 Sealing of cuts in skin by blood clotting

C3.2.4 Differences between the innate immune system and the adaptive immune system

C3.2.5 Infection control by phagocytes

C3.2.6 Lymphocytes as cells in the adaptive immune system that cooperate to produce antibodies

C3.2.7 Antigens as recognition molecules that trigger antibody production

C3.2.8 Activation of B-lymphocytes by helper T-lymphocytes

C3.2.9 Multiplication of activated B-lymphocytes

C3.2.10 Immunity as a consequence of retaining memory cells

C3.2.11 Transmission of HIV in body fluids

C3.2.12 Infection of lymphocytes by HIV with AIDS as a consequence

C3.2.13 Antibiotics

C3.2.14 Evolution of resistance to several antibiotics

C3.2.15 Zoonoses

C3.2.16 Vaccines and immunization

C3.2.17 Herd immunity and the prevention of epidemics

C3.2.18 Evaluation of data related to the COVID-19 pandemic

C4.1.1 Populations

C4.1.2 Estimation of population size by random sampling

C4.1.3 Random quadrat sampling to estimate population size for sessile organisms

C4.1.4 Capture–mark–release–recapture and the Lincoln index

C4.1.5 Carrying capacity and competition for limited resources

C4.1.6 Negative feedback control of population size by density-dependent factors

C4.1.7 Population growth curves

C4.1.8 Modelling of the sigmoid population growth curve

C4.1.9 Competition versus cooperation in intraspecific relationships

C4.1.10 A community as all of the interacting organisms in an ecosystem

C4.1.11 Herbivory, predation, interspecific competition, mutualism, parasitism and pathogenicity

C4.1.12 Mutualism as an interspecific relationship that benefits both species

C4.1.13 Resource competition between endemic and invasive species

C4.1.14 Tests for interspecific competition

C4.1.15 Use of the chi-squared test for association between two species

C4.1.16 Predator–prey relationships

C4.1.17 Top-down and bottom-up control of populations in communities

C4.1.18 Allelopathy and secretion of antibiotics

C4.2.1 Ecosystems

C4.2.2 Sunlight

C4.2.3 Flow of chemical energy through food chains

C4.2.4 Construction of food chains and food webs

C4.2.5 Supply of energy to decomposers

C4.2.6 Autotrophs

C4.2.7 Use of light as the external energy source

C4.2.8 Heterotrophs

C4.2.9 Release of energy in both autotrophs and heterotrophs

C4.2.10 Classification of organisms into trophic levels

C4.2.11 Construction of energy pyramids

C4.2.12 Reductions in energy availability at each successive stage in food chains

C4.2.13 Heat loss to the environment in both autotrophs and heterotrophs

C4.2.14 Restrictions on the number of trophic levels in ecosystems

C4.2.15 Primary production as accumulation of carbon compounds in biomass by autotrophs

C4.2.16 Secondary production as accumulation of carbon compounds in biomass by heterotrophs

C4.2.17 Constructing carbon cycle diagrams

C4.2.18 Ecosystems as carbon sinks and carbon sources

C4.2.19 Release of carbon dioxide into the atmosphere during combustion

C4.2.20 Analysis of the Keeling Curve in terms of photosynthesis, respiration and combustion

C4.2.21 Dependence of aerobic respiration on atmospheric oxygen produced by photosynthesis

C4.2.22 Recycling of all chemical elements required by living organisms in ecosystems