biology - the chemistry of life

• Where prokaryotes are found or live

  • sea ice
  • deep sea
  • plants
  • on people
  • ophelia lights
  • nuclear contaminated sites
  • hydrothermal / volcanic vents
  • extreme temp / ph / conditions
• Archaea are either / both

  • thermophilic
  • acidophilic
• Recycling - bacteria


  Cleans waste and water + accompanied by UV light, rendering water clean
• Pharmaceuticals - genetically modified bacteria


  • Make pharmaceuticals like human insulin, growth hormone, interferon
  • Put gene to code for human insulin into e coli genome
  • Builds insulin with ribosomes
• Glutamate – refolding in the wrong way
• Disulfide bridge
• Ionic bonds (urea)?
• Photosynthesis
• Endosymbiosis


  Formation of nuclear envelope – eating purple bacteria – this purple bacteria became a mitochondrion inside the cell and formed a symbiotic relationship
• Thickness of ozone layer
• Respiration – needs o2 for aerobic respiration – 20% more effective
• Endosymbiosis
• Temperature


  Kinetic energy increases, molecules pulling apart from each other. All R groups affected by temperature.
• pH


  Putting protein in an area with TOO MANY protons / no protons at all. R groups with Carboxyl groups (can lose proton) / Amino groups (can gain proton) affected. Ionic interactions are affected. H groups unaffected.
• Addition of excess polar compound

  Polar R groups affected. Molecules with dipole dipole / H bonds affected.
• Addition of excess nonpolar compound

  Non Polar R groups affected. Molecules with dispersion forces affected.
• Ozone layer took a large amount of time to form due to the time stretch of the oxygenation event executed by algae and photosynthesis
• Before terrestrial animals and unicellular eukaryotes, the earth's atmosphere was extremely radioactive, with CO2, ammonia and methane being abundant in the air. this would've been too radioactive for life to be sustained there
• The only place with little to no radiation was the ocean – bacteria in the ocean were then formed into cyanobacteria (blue and green algae)
• Cyanobacteria underwent photosynthesis, absorbing CO2 and releasing O2 into the atmosphere
• UV splits oxygen into radicals which can react with other O2 molecules to create O3. This allowed for an ozone layer to be formed, blocking out the radiation + levels of CO2, ammonia, methane
• Prokaryotic cells


  They are generally smaller than eukaryotes
• Ribosomes reside in the nucleoid region of the cell
• Prokaryotes and eukaryotes use the same genetic code
• Limitation of cell size

  Difficulty of moving molecules within a large cell. Diffusion of proteins — takes ages for them to be transported as the cell is too big.
• Similarities between Prokaryotes and Eukaryotes

  • Both have ribosomes
  • Both have cytoplasm
  • Both contain DNA information
• Differences between Prokaryotes and Eukaryotes

  • Prokaryote is unicellular, Eukaryote does not
  • Prokaryotes have no membrane bound organelle unlike eukaryotes
  • Each have different types of ribosomes
• Mitochondria


  Powerhouse of the cell. Double membrane: outer membrane and a high convoluted, folded in inner membrane, whose inwards projections are called cristae (singular - crista). Carry out the aerobic respiration of all eukaryotic cells. Maintenance of pH in inter membrane space.
• Chloroplast


  Mainly happens in plant cells + single cells. Double membrane: outer and inner membrane that forms a complex internal network of Lamellae / thylakoids. Outer, inner membranes allow pH and environmental control. Proteins – involved in photosynthesis for ATP process. This is located in thylakoids.
• Nucleus


  Command centre of the cell. Surrounded by a double membrane / nuclear envelope. Allows mRNA to move out, nucleotides + necessary components to move in. Presence of nuclear (annular pores (50 nm in diameter). Nucleolus: subregion of nucleus that transcribes ribosomal genes – making ribosomes.
• Origin of the nucleus

  Made have formed from INVAGINATIONS of plasma membrane around the nucleoid of an ancient prokaryote. Over time -- invagination made it form into a nuclear envelope and thus a true nucleus.
• Origin of mitochondria


  Arose from primary endosymbiosis of a purple bacteria – this single event gave rise to the mitochondria in all eukaryotes. Ate through phagocytosis – ate purple bacteria and absorbed into cells. Vacuole ended up with mitochondria. Primary endosymbiosis – one organism eats another single cell, single cell because of mitochondria. Genetic information of the purple bacteria were then transferred to the host cell.
• Origin of chloroplasts


  Originated from primary endosymbiosis of photosynthetic cyanobacteria (ie, algae). Cyanobacteria – eaten by another bacteria (phagocytosis) – become chloroplast. Is an endosymbiont – the cell thats being eaten during endosymbiosis. A double membrane built about cyanobacteria.
• Primary vs Secondary endosymbiosis


  Primary: cell eating another cell. Secondary: eating a cell that already went through endosymbiosis (eating another eukaryotes). Chloroplast derived from endosymbiotic, eukaryotic cells rather than a prokaryote. A eukaryote eats another eukaryote with chloroplast and takes it.
• Evidence for endosymbiotic origin of mitochondria and chloroplasts

  • Organelles appear morphologically similar to bacteria
  • Surrounded by an outer membrane similar to a cell membrane, while their inner membrane invaginates to form lamellae or cristae
  • Semi autonomous, retaining its own genome (ie. mitochondria has mitochondrial RNA and DNA –transferring the genome of the host cell)
  • Retain their own machinery for synthesis proteins, including ribosomes
  • Metabolisms – existing prokaryotic organisms (cyanobacteria for chloroplast, purple bacteria for mitochondria)
  • Chloroplast in some species still have bacterial peptidoglycan wall b/w inner and outer membranes
• Similarities between plant and animal cells

  • Mitochondria
  • Have nucleus – composed of dna
  • Have cytoskeleton
  • Cell membrane
  • Organelles
  • Free ribosomes in cytoplasm
  • Golgi apparatus
  • Peroxisomes
• Differences between plant and animal cells

  • Plant cell has a rigid cell wall – it changes shape. Animals do NOT have a cell wall, instead having a cell membrane that keeps the structure from falling apart
  • Chloroplast present in plant cells
  • Plants: have extremely large vacuoles
• Membrane-bound organelles in Eukaryotes

  Increase the efficiency of cellular activities in eukaryotes. Streamlines process of protein formation and biologically intermediate movements. Division of labour.
• Unidentified membrane-bound body


  Nucleus - contains MOST of the DNA and is the site of DNA replication. Has nuclear pores, allowing things to go in and out on nucleus (RNA). Site where gene transcription turned on or off. Nucleolus - subregion of nucleus containing 1 transcribing ribosomal genes. Nucleus - continuous w/ endoplasmic reticulum. Nuclear envelope is also a double membrane — invagination of its cell wall.
• Folds of inner mitochondrial membrane

  Increase surface area of membrane