The Atmosphere + plant chemistry Flashcards
describe the troposphere (4)
a planetary boundary up to 1km
an inversion/friction layer
mass of air up to 80%
lots of h2o
What layer does the stratosphere include and why is it significant?
- contains the ozone layer which protects life on earth
- ozone absorbs UV light which reduced UV light to earth surface allowing organisms to form
what are some properties of O3?
- a strong absorber of longer wavelengths UV radiation and the absorbed energy heats the atmosphere
what is the ideal gas law?
Pv = nRT
What does the ideal gas law allow us to calculate?
calculates and exactly inter convert concentration and mixing ratio at a given pressure and temperature
what do the following letters stand for in the ideal gas law P ? V? n? R? T?
P = pressure in pa V = volume in m3 n = number of moles R = 8.314 jk-1 mol-1 T = temperature in kelvin
How can you calculate pressure?
pressure = force/area
what is the purpose of the thermosphere, mesosphere and stratosphere?
- shield life on earth from the damaging rays
define mixing ratio
the fraction of the air made up of a particular species
define concentration
the amount of a substance per unit volume
what does 1 mole equal?
6.022 x 10^23
How can you calculate mass?
mass = volume x density
how does mixing ratio and concentration change at different altitudes?
- mixing ratio is constant at different altitudes
- concentration changes with altitude and temperature
what is the conversion of 1ppm to molecules cm-3?
1 ppm = 2.5 x 10^13 molecules cm^-3
what is the link between abundance of a gas and its reactivity?
lower abundance of a gas in the atmosphere means higher reactivity
describe the properties of vascular plants
they have vessel like structure to transport nutrients and water
name the structures in plants involved in its chemistry
- DNA
- protein
- lipids
- phytochemical pigments
- plant hormones
- self-defence chemicals
How are nutrients taken up by plants?
- transpiration, provides a pilling force
- absorption, water and nutrients absorbed by root
- conduction, upward transport of h2o and nutrients
what is a rhizosphere?
a narrow region of soil in the vicinity of plant roots in which the chemistry and microbiology is influenced by their growth, respiration, and nutrient exchange.
name the main components of the rhizosphere
- root exudates
- dead root cells
- microorganisms
what are root exudates? (3)
- secondary metabolites of photosynthesis
- composed of amino acids and organic acids
- carbohydrates, sugars, vitamins, mucilage
what is mucilage?
- a polysaccharide
- maintains plant-soil contact
- symbolise relationship with soil dwelling funghi
- prevents roots from damage
what are organic acids?
small organic molecules with at least one carboxylic acid
describe a carboxylic acid
C = O
- R
- OH
