Membranes, Proteins, DNA and Gene Expression

Gas Exchange Surfaces and Fick's LawSign up

know the properties of gas exchange surfaces (large surface area to volume ratio, thin surface, concentration gradient) · understand how the rate of diffusion depends on these properties and can be calculated using Fick's Law of Diffusion · understand how the mammalian lung is adapted for rapid gaseous exchange

Cell Membranes and TransportSign up

know the structure and properties of cell membranes · understand how models such as the fluid mosaic model are interpretations of data on membrane structure and properties · CORE PRACTICAL 3: investigate membrane properties including the effects of alcohol and temperature on membrane permeability · understand osmosis in terms of free water movement through a partially permeable membrane down a water potential gradient · understand passive transport (diffusion, facilitated diffusion), active transport (ATP-driven, including endocytosis and exocytosis), and the roles of carrier and channel proteins

Proteins: Amino Acids, Bonds and StructureSign up

know the basic structure of an amino acid (structures of specific amino acids are not required) · understand how polypeptides and proteins form via condensation/peptide bonds · understand how primary structure determines secondary and tertiary structure; differences between globular and fibrous proteins and the bonds involved · know the molecular structure of a globular and a fibrous protein (haemoglobin, collagen) and how their structures relate to their functions

Enzymes: Mechanism, Specificity and KineticsSign up

understand enzyme action and specificity in terms of three-dimensional structure · understand that enzymes are biological catalysts that lower activation energy · know that intracellular enzymes catalyse reactions inside cells and extracellular enzymes catalyse reactions outside cells · CORE PRACTICAL 4: investigate the effects of temperature, pH, enzyme concentration and substrate concentration on the initial rate of enzyme-catalysed reactions

DNA Structure, Replication and the Genetic CodeSign up

know the basic structure of mononucleotides (deoxyribose or ribose + phosphate + base: thymine, uracil, adenine, cytosine or guanine) and the structure of DNA and RNA (polynucleotides linked by phosphodiester bonds) · know how complementary base pairing and hydrogen bonding form the DNA double helix · understand DNA replication and the role of DNA polymerase · understand how Meselson and Stahl's classic experiment supported the accepted theory of DNA replication · understand the nature of the genetic code (triplet, non-overlapping, degenerate); know that a gene is a base sequence on DNA coding for a polypeptide

Protein Synthesis and MutationsSign up

understand protein synthesis (transcription and translation); roles of RNA polymerase, mRNA, tRNA, ribosomes, start and stop codons; the antisense template strand, codons on mRNA, anticodons on tRNA · understand how errors in DNA replication can give rise to mutations (substitution, insertion, deletion) · know that some mutations cause cancer or genetic disorders, but many have no observable effect

Inheritance, Genetic Screening and EthicsSign up

understand the terms gene, allele, genotype, phenotype, recessive, dominant, codominance, homozygote, heterozygote · understand patterns of inheritance including monohybrid inheritance and genetic pedigree diagrams · understand sex linkage on the X chromosome (red-green colour blindness) · understand how the cystic fibrosis gene mutation impairs gaseous exchange, digestive and reproductive systems · understand uses of genetic screening (carrier identification, PGD, prenatal testing including amniocentesis and chorionic villus sampling) and the implications of prenatal screening · identify and discuss ethical and social issues relating to genetic screening (religious, moral and social viewpoints)