C4 and CAM Plants

– O2 competes with CO2 for rubisco’s active site – rubisco catalyzes two reactions: 1) addition of carbon to RuBP; forms 2 PGA molecules (photosynthesis) 2) addition of oxygen to RuBP; forms 1 PGA and one glycolate (photorespiration) – photorespiration decreases the production of carbohydrates by removing PGA from the Calvin cycle – glycolate is…

Alternative Metabolic Pathways

Carbohydrates are the first nutrient most organisms catabolise for energy, however, living things must metabolize other energy-rich nutrients to obtain energy in times of starvation Protein Catabolism – first digested into amino acids – amino groups are removed (deamination; amino group à ammonia [NH3]) – remaining portion of amino acid converted into various components of…

Shapes of Molecules

The shape of a molecule determines many of its properties; For example: C4H10 is the formula for 2 separate molecules n-butane and isobutene Melting Point    -138°C                   -159°C Boiling Point     -0.5°C                    -12°C Enzymes—shape compatible with those molecules whose reactions they promote i.e.  the enzyme sucrase breaks down the sugar molecule sucrose The shape of a…

Enthalpy Change

Enthalpy change is also known as heat of reaction, enthalpy of reaction, change in heat content. Enthalpy = total energy of a system It is impossible to measure the total kinetic and potential energy of a system, so instead we measure enthalpy change (using calorimeters). Enthalpy Change –  is the energy absorbed from or released…

What is Bioamplification?

Bioamplification is the accumulation of toxic pollutants in an animal. Toxins can be removed from the bodies of animals through sweating and urination, but these toxins need to be water soluble. DDT, DDE, PCBs, toxaphene, and the organic forms of mercury and arsenic do biomagnify in nature. These substances are consequently known as ‘persistent organic…