Quiz 6: Photsyn/ Respiration Flashcards
T or F , both plants and humans respire and photosynthesize
false; only plants
autotroph
organism that can synthesize their own food from non-living compounds
heterotroph
organism that must consume food that is ready made
describe formula cellular respiration
chemical breakdown of food substances, resulting in libration of energy
C6H12O6 (glucose) + 6O2 –> 6CO2 + 6H2O + energy (ATP)
* consume O and release CO2 and energy
where does cellular respiration take place
mitochondria
what is optimum temp for respiration ?
0 - 45 C
describe cellular respiration
transformation chemical energy in food into chemical energy cells can use aka ATP
t or f : respiration increases during flowering stage
true
t or f respiration is less significant in woody than herbaceous plants
true
describe photosynthesis
process in which light energy is used to form food from CO2 and water
where does photosynthesis take place?
chloroplasts (plastid)
describe chemical reaction of photosynthesis
6H2O + 6CO2 +energy (sunlight) –> C6H12O6 + 6O2
what chemical formula of carbohydrates
C6H12O6
how is CHO used by plants?
- source immed energy to function, grow, reproduce
- energy reserves ex before winter
- formation of plant tissues ; sugars transformed to proteins, lipids, produce leaves, wood ect
what factors influence photosynthesis
- temperature: stops below 0C
- Concentration of CO2 in air ; more CO2 in air = more photo.
- intense light; more light= more photo.
- leaf surface area exposed to light ex. lower leaves thinner and longer
- availability of water in soil
what is optimum temp for photosynthesis
20 -35C
what are 2 stages of photosynthesis
- light dependent reaction: captures energy in light and uses to split H2O and make ATP and NADPH
- Calvin cycles : captures CO2 and uses products of light reaction to produce CHO
describe carbon fixation, when does it occur
Calvin cycle; ATP & NADPH generated in first step used to take CO2 and break apart, reassemble carbons into glucose
ie take carbon from inorganic molecule and make organic
what is light
energy in form of electric and magnetic fields (electromagentic radiation)
what light wave does plants relfect ie not absorb
green ( 500-550 nm)
why are plants green
photosynthetic pigment chlorophyll reflects green and yellow wavelengths
what are the 4 photosynthetic pigments and where are they found
- chlorophyll a - green chloroplasts
- chlorophyll b- green chloroplasts
- carotene- orange yellow - chromoplasts
- xanthophylls yellow to colourless chromoplasts
what is a non photosyntehtic pigment
anthocyanin - purple red, vacuole
why can wee see fall colour?
lack of chlorophyll, can now see other pigments
when is artificial illumination effective?
- must provide blue and red wavelengths absorbed by chloroplast pigments
what is osmosis
movement of water from an area of high concentration to low across a semi permeable membrane (cell wall)
what are plant cells largely composed of
- high concentration salts, sugars , low concentration water molecules
what are soil particles largely composed of
- high concentration water, low of other solutes
what is chemical formula of table salt
NaCl
t or f when cell is turgid water uptake stops
false; just slows
what is plasmolysis
loosening of the cytoplasm:
reverse pathway of osmosis
-occurs in high salt soils
-soil will have a higher salt content than plants so water will move out of plant cells to soil
what is transpiration
loss of water vapour from plant mostly through stoma
how is water pulled up the xylem
- water polar molecule
- capillary action and polarity combine to pull water up xylem columns
- water forms unbroken chain; as one water molecule leaves leaf another is pulled up
what factors affect transpiration?
- temperature: increases as temp increases ( causes plants to open stoma)
- relative humidity: transpiration decrease as humidity increases
- win and air movement: increased air movement = increased trans.
- soil moisture availability: trans. decrease as soil water decreases
- type of plants
