chapter four: photosynthesis and cellular respiration Flashcards
state the inputs and outputs of the light dependent stage
inputs:
- sunlight
- NADP+
- H20
- ADP + Pi
outputs:
- NADPH
- ATP
- O2
state the inputs and outputs of the light independent stage
inputs:
- NADPH
- ATP
- CO2
outputs
- NADP+
- ADP
- glucose - C6 H12 O6
state the location within a chloroplast where each stage occurs
- the granum
- the stroma
- light independent occurs in the stroma
- light dependent occurs in the granum
state the role of rubisco
rubisco is an enzyme that fixes CO2 during the light independent stage
- converts inorganic carbon dioxide molecules into organic molecules
- (takes CO2 gas from the air and creates a solid substance)
rubisco can bind to carbon dioxide or oxygen
rubisco works efficiently when:
- carbon dioxide levels in leaves are high
- oxygen levels are low
- when temperatures are moderate
describe photorespiration
- when does it occur
a process in which plants take up oxygen rather than carbon dioxide in the light, resulting in photosynthesis being less efficient
- when the stomata is closed, O2 accumulates
- more O2 (and less CO2) will bind to rubisco
- as temperature increases, rubisco prefers O2 to CO2
occurs when:
- the Rubisco enzymes capture oxygen, instead of carbon dioxide
- occurs more frequently on hot, dry days when C3 plants close their stomata to prevent water loss
state how C4 plants have adapted to avoid photorespiration
(plants in tropical areas - hot and humid)
- uses different cells for fixing carbon (PEP carboxylase) and producing glucose
the LI stage is split into 2 stages
- carbon fixation (PEP carboxylase)
- calvin cycle - produces glucose
state how CAM plants have adapted to avoid photorespiration
(CAM = plants in hot and dry areas)
- as rubisco binds to O2 better than CO2 in higher temperatures
the LI stage is split into 2 stages:
- at two different times
- carbon fixation occurs at night (lower temperate)
- stomata can be open at night due to lower temperatures and lose less water
- glucose is made during the day
explain how light availability/intensity can affect the rate of photosynthesis
The rate of photosynthesis increases with increasing and the rate of light intensity as there is more energy to drive the reaction
- The rate will plateau when another factor limits the reaction
explain how water availability can affect the rate of photosynthesis
When water supply becomes too little, the rate of photosynthesis declines and then stops because closed stomata prevent the uptake of carbon dioxide needed for the Calvin cycle
- Stopping photosynthesis and altering the balance that normally exists between energy capture and
energy use in photosynthesis. Prolonged periods of water deficit can cause plant death.
explain how carbon dioxide concentration can affect the rate of photosynthesis
The rate of photosynthesis increases with increasing concentration of carbon dioxide until a limit is reached
explain why temperature affects the rate of photosynthesis
the rate of photosynthesis increase with the increase of temperature as the molecules are moving faster and are more likely to collide
- photosynthesis rate decreases when the enzymes catalysing the reaction begin to denature
state the inputs and outputs of glycolysis
inputs:
- glucose
- ADP
- NAD
outputs:
- pyruvic acid
- NADH
- 2ATP
state the inputs and outputs of Krebs cycle
inputs:
- acetyl Co A
- NAD/FAD
- ADP
outputs:
- 2ATP
- NADH
- FADH
- CO2
state the inputs and outputs of the electron transport chain
inputs:
- NADH/FADH
- O2
- ADP
outputs:
- NAD/FAD
- H2O
- 26-28 ATP
state how much ATP is made in each of the three stages of cellular respiration
- Glycolysis = 2ATP
- Krebs cycle = 2ATP
- Electron transport chain = 26-28 ATP
state where glycolysis occurs
the cytoplasm
state where in a mitochondria Krebs cycle occurs
the matrix
where in a mitochondria does the electron transport chain occurs
the cristae
write the equation for lactic acid fermentation in animals
- state the inputs (reactants) and outputs (products)
- glucose —> lactic acid + 2ATP
inputs
- glucose - C6 H12 O6
outputs:
- lactic acid
- 2ATP
write the equation for ethanol fermentation in yeasts
- state the inputs (reactants) and outputs (products)
- glucose —> ethanol + carbon dioxide + 2ATP
inputs:
- glucose
outputs:
- ethanol
- carbon dioxide
- 2ATP
state how glucose availability affects the rate of cellular respiration
an increase in glucose concentration leads to an increase in the rate of cellular respiration, this rate eventually plateau due to limiting factors
- as glucose concentration increases, the more glucose their is available
state how oxygen availability affects the rate of cellular respiration
as oxygen concentration increases so does the rate of cellular respiration, however the levels eventually plateau due to limiting factors
- as oxygen concentration increases, so does the amount of oxygen there is available
explain why temperature affects the rate of cellular respiration
- As the temperature increases further, the respiration rate also increases until the optimal temperature for an organism’s cells is reached
- At low temperatures, collisions between substrate and enzyme molecules are less frequent, resulting in a low rate of respiration
- At temperatures above the optimal, heat denaturation of the enzymes begins and a steep decline in respiration rate occurs.
describe two ways CRISPR-Cas9 could be used to improve crop yield
describe one potential way CRISPR-Cas9 could be used to increase the efficiency of photosynthesis
rubisco (enzyme) produced by transcription and translation in which the genes are target site for genome editing
- altering the genes that code for rubisco to make it less likely to bind with oxygen —> from here, deleted genes that increases the binding of rubisco and O2 or inserting genes that would promote rubisco to bind to CO2
- rubisco is more efficient at binding with CO2 for carbon fixation photosynthetic pathway inn which reduces photorespiration
what benefits does using CRISPR-Cas9 have over other methods of increasing crop yield
CRISPR-Cas9 targets certain genes that impact crop yield by:
- insert genes to improve
- knocking out gene that have a negative effect
define biofuel
biofuel is the product of biomass
fuel deprived from living matters
list 3 substances that can be used as biomass
- ethanol
- diesel
- petroleum
describe how biomass can be converted to biofuel using fermentation
biomass (solid or liquid) can be converted through fermentation by microbes to biofuel/biogas
- the biofuel/biogas can burned as fuel
