Biology

• neonicotinoid pesticides irreversibly bind with acetylcholine receptors on the postsynaptic membrane as an effect of the neurotransmission of a nerve impulse between neurons in an insect
• Potassium moves acroos the membrane of a neuron during repolarisation vis facilitated diffusion
• Fats and cholesterol are transported in the blood as groups of molecules in lipoprotein complexes
• A haploid set of chromosomes from the mother are always passed to the next generation as a result of sexual reporduction
• splitting of the centromeres, random assortment of chromosomes, or reduction division of chromosomes take place during Meiosis I and Meiosis II
• Huntington's disease has the genotype Hh
• For the formation of peat, you need wet, anaerobic and acidic conditions
• Cnidaria shows radial symmetry
• The insides of alveoli are prevented from sticking together by surfactant produced by type II pneumocytes
• Water molecules stay within the axons due to the plasma membrane
• Eukaryotic DNA has introns whereas Prokaryotic DNA doesn't
• Polysomes are many ribosomes joined to one mRNA
• When pyruvate is converted to acetyl CoA in the link reaction, it is decarboxylated
• Both ATP and reduced NADP are needed to change products of the carboxylation of ribulose bisphosphate into triose phosphate
• The distribution of height within a population could be caused by multiple genes
• The main aims of epidemiological research are:

  • To test vaccine effectiveness
  • To identify distribution of disease
• When lifting an object such as an apple, the movement of the elbow is called flexion and the state of the tricep is relaxed
• When the presence of proteins such as albumin is seen in a urine sample, this indicates that the patient has kidney disease, which damages the cortex.
• The total DNA of a zygote consists of DNA from both the sperm's nucleus and the Egg's nucleus, as well as the DNA from the Egg's Mitochondria
• Glucose, galactose and fructose are all examples of monosaccharides
• lactose, sucrose and maltose are all examples of disaccharides
• Cellulose, glycogen and starch are all examples of polysaccharides
• Nutrient


  A chemical substance found in foods that is used in the human body
• Essential nutrients


  Those that cannot be synthesised by the body and must be ingested as part of the diet
• Non-essential nutrients


  Can be made by the body or have a replacement nutrient which serves the same dietary purpose
• Carbohydrates are not considered essential nutrients as human diets can obtain energy from other sources without ill effect
• Malnutrition is a health condition caused by a deficiency, imbalance or excess of nutrients in the diet
• Malnutrition can be caused by an improper dietary intake of nutrients – e.g. overnutrition (too much) or undernutrition (not enough)
• Malnutrition can be caused by the inadequate utilisation of nutrients by the body – e.g. due to illness or disease
• Calorimetry

  Equation for calculating the energy content of a food source via calorimetry: Energy = Mass of water × 4.2 × Temp inc. (Joules) (g) (J/g°C) (°C)
• Calorimetry

  Water requires 4.18j to raise the temp of 1g by 1°C, this is the specific heat capacity of water
• Amino acids

  There are 20 different amino acids which are universal to all living organisms
• Essential amino acids

  Cannot be produced by the body and must be present in the diet
• Non-essential amino acids


  Can be produced by the body and are therefore not required as part of the diet
• Conditionally non-essential amino acids

  Can be produced by the body, but at rates lower than certain conditional requirements (e.g. during pregnancy or infancy) – they are essential at certain times only
• Phenylketonuria (PKU) is a genetic condition that results in the impaired metabolism of the amino acid phenylalanine
• PKU is an autosomal recessive disease caused by a mutation to the gene encoding the enzyme phenylalanine hydroxylase
• Phenylalanine hydroxylase (PAH) normally converts excess phenylalanine within the body into tyrosine
• In people with PKU, the excess phenylalanine is instead converted into phenylpyruvate (also known as phenylketone)
• This results in a toxic build up of phenylketone in the blood and urine (hence phenylketonuria)