i) Know the properties of gas exchange surfaces in living organisms (large surface area to volume ratio, thickness of surface, difference in concentration).
ii) Understand how the rate of diffusion is dependent on these properties and can be calculated using Fick’s Law of Diffusion.
iii) Understand how the structure of the mammalian lung is adapted for rapid gaseous exchange.
i) Understand the mechanism of action and the specificity of enzymes in terms of their three-dimensional structure.
ii) Understand that enzymes are biological catalysts that reduce activation energy.
iii) Know that there are intracellular enzymes catalysing reactions inside cells and extracellular enzymes produced by cells catalysing reactions outside of cells.
i) Understand the process of DNA replication, including the role of DNA polymerase.
ii) Understand how Meselson and Stahl’s classic experiment provided new data that supported the accepted theory of replication of DNA and refuted competing theories.
i) Understand how errors in DNA replication can give rise to mutations.
ii) Understand how cystic fibrosis results from one of a number of possible gene mutations.
i) Know the meaning of the terms: gene, allele, genotype, phenotype, recessive, dominant, incomplete dominance, homozygote and heterozygote.
ii) Understand patterns of inheritance, including the interpretation of genetic pedigree diagrams, in the context of monohybrid inheritance.
Understand how the expression of a gene mutation in people with cystic fibrosis impairs the functioning of the gaseous exchange, digestive and reproductive systems.
i) Understand the uses of genetic screening, including the identification of carriers, pre-implantation genetic diagnosis (PGD) and prenatal testing, including amniocentesis and chorionic villus sampling.
ii) Understand the implications of prenatal genetic screening.
Be able to identify and discuss the social and ethical issues related to genetic screening from a range of ethical viewpoints.
i) Know the structure and properties of cell membranes.
ii) Understand how models such as the fluid mosaic model of cell membranes are interpretations of data used to develop scientific explanations of the structure and properties of cell membranes.
Understand what is meant by osmosis in terms of the movement of free water molecules through a partially permeable membrane (consideration of water potential is not required).
i) Understand what is meant by passive transport (diffusion, facilitated diffusion), active transport (including the role of ATP as an immediate source of energy), endocytosis and exocytosis.
ii) Understand the involvement of carrier and channel proteins in membrane transport.
i) Know the basic structure of mononucleotides (deoxyribose or ribose linked to a phosphate and a base, including thymine, uracil, cytosine, adenine or guanine) and the structures of DNA and RNA (polynucleotides composed of mononucleotides linked through condensation reactions).
ii) Know how complementary base pairing and the hydrogen bonding between two complementary strands are involved in the formation of the DNA double helix.
i) Understand the process of protein synthesis (transcription) including the role of RNA polymerase, translation, messenger RNA, transfer RNA, ribosomes and the role of start and stop codons.
ii) Understand the roles of the DNA template (antisense) strand in transcription, codons on messenger RNA and anticodons on transfer RNA.
Understand the nature of the genetic code (triplet code, non-overlapping and degenerate).
Know that a gene is a sequence of bases on a DNA molecule that codes for a sequence of amino acids in a polypeptide chain.
i) Know the basic structure of an amino acid (structures of specific amino acids are not required).
ii) Understand the formation of polypeptides and proteins (amino acid monomers linked by peptide bonds in condensation reactions).
iii) Understand the significance of a protein’s primary structure in determining its three-dimensional structure and properties (globular and fibrous proteins and the types of bonds involved in its three-dimensional structure).
iv) Know the molecular structure of a globular protein and a fibrous protein and understand how their structures relate to their functions (including haemoglobin and collagen).
CORE PRACTICAL 3
Investigate membrane structure, including the effect of alcohol concentration or temperature on membrane permeability.
CORE PRACTICAL 4
Investigate the effect of enzyme and substrate concentrations on the initial rates of reactions.