bio 2017 p1

• give 2 pieces of evidence that cells ARE undergoing mitosis

  cells aren't arranged in pairs which they would if they were undergoing meiosis

  chromosomes are visible because they have been condensed
• give one way chromosome structure differs along the length

  there is a difference in base sequence
• what is a homologous pair of chromosomes

  they carry the same genes
• give two ways which arrangement of prokaryotic dna is different from arrangement of human dna

  prokaryotic dna is circular

  prokaryotic dna has plasmid dna
• what is species richness

  number of different species in a community
• explain how formation of the enzyme substrate complex increases the rate of reaction

  reduces the activation energy

  without enzymes very few substrates have sufficient energy for the reaction
• points for talking about enzymes

  lowers activation energy

  binding alters tertiary shape

  causes active site to change shape
• structure of amino acid

  carboxyl group, amino group, r group, hydrogen

  
• degenerate code meaning

  many different codons can be used to code for the same amino acid
• how does treatment for antivenom work

  injected antibodies bind to toxin to destroy it
• explain vaccination with humoral response

  once injected specific b cells undergo mitosis to produce plasma cells and memory b cells. once reinfected memory cells are able to differentiate to plasma cells so the response is much faster
• describe the role of the 2 enzymes involved in semi conservative replication of DNA

  DNA helicase: breaks the hydrogen bonds between the nucleotides

  DNA polymerase: joins together nucleotides forming phosphodiester bonds
• describe structure and the human gas exchange (6)

  trachea, bronchi, bronchioles, alveoli

  when breathing in: diaphragm contracts and external intercostal muscles contract

  volume increases and pressure decreases in thoracic cavity

  when breathing out: internal intercostal muscles contract and diaphragm relaxes

  volume decreases and pressure increases in thoracic cavity
• compare structure and properties of triglycerides and phospholipids

  both contain glycerol

  tri= 3 fatty acids, phos= 2 fatty acids and phosphate

  both contain ester bonds

  phos= hydrophobic tail, hydrophillic head tri= hydrophobic

  both insoluble in water

  phos form monolayer but tri dont
• describe how lactose if formed and where in cell it would be attached to a polypeptide to form glycoprotein

  attaches to polypeptide in Golgi apparatus

  formed by condensation reaction of glucose and galactose forming glycosidic bond