Photosynthesis and Respiration

Question 1

what kind of reaction is photosynthesis

Answer 1

synthesis reaction

Question 2

what does respiration use

Answer 2

products of photosynthesis

Question 3

plants are autotrophic what does this mean

Answer 3

with the input of light, carbon dioxide, and water they are self-sufficient

Question 4

what is photosynthesis

Answer 4

it is the manufacture of food (carbohydrates) from carbon dioxide and water in the presence of light and chlorophyll in living green plant tissue

Question 5

is photosynthesis an endo or exo reaction

Answer 5

it is endo

Question 6

what colors is the chlorophyll efficient at trapping

Answer 6

red and blue

Question 7

what is in the reaction of photosynthesis (both the reactant and product sides)

Answer 7

glucose, water, and oxygen

6CO2 + 12H2O —-> C6H12O6 + 6H2O + 6O2

Question 8

what is the process of photosynthesis

Answer 8

sunlight is captured by the chloroplast and the light energy is used to break apart water and carbon dioxide

oxygen is given off by the stomata

hydrogen from the water molecule is combined with carbon to make glucose which is created by photosynthesis

water is released

Question 9

where does the majority of photosynthesis take place

Answer 9

the leaves

Question 10

what are the inputs of photosynthesis

Answer 10

carbon dioxide (from the atmosphere, a product of respiration, greenhouse gasses)
water (from soil or water vapor)

Question 11

what are the products of photosynthesis

Answer 11

glucose- six-carbon sugar molecules used for energy

oxygen

water- an input and product

Question 12

what are 6 factors that affect photosynthesis rate

Answer 12

• light quality (red/blue)
• light intensity (shade)
• light duration (day length)
• carbon-dioxide concentration
• temperature +10*c = 2x photosynthesis rate
• water availability

Question 13

what are the two major classifications of photosynthesis

Answer 13

C3 and C4

Question 14

what respiration only happens in one plant

Answer 14

photorespiration happens in C3 plants only

Question 15

what are the benefits to C3 plants being able to carry out both respiration and photorespiration

Answer 15

that is more efficient under cooler temperatures and low light intensities

Question 16

what temperature are C4 plants more efficient at

Answer 16

higher temperatures

Question 17

why is C4 more efficient under higher temperatures

Answer 17

use carbon dioxide more efficiently than C3 plants. photosynthesis rate of C4 plants can be much higher

transloctation of water and nutrients can occur twice as fast

have better water use efficiency

respond to higher light intensities

Question 18

what are the optimum temperatures of C3 and C4 plants

Answer 18

C3- 15 to 25*C

C4- 25 to 40*C

Question 19

what is respiration in plants

Answer 19

it is the controlled release of energy that has been captured and stored in photosynthesis

it is an exothermic reaction

it is used to live
all cells resporate

Question 20

what is the reactants and products of respiration

Answer 20

glucose, oxygen, water turn into carbon-dioxide, water, and energy
C6H12O6 + 6O2 —-> 6CO2 + 12H2O + energy

Question 21

what is the difference between the two types of respiration

Answer 21

photorespiration- is non-essencial respiration by C3 plants which depends on the light intensity and duration

normal respiration- all plants use the energy stored during photosynthesis in plant presses (making new cells, building tissue, making the inflorescence). it occurs at the same rate in the day as at night

Question 22

what are 5 factors that affect respiration rate

Answer 22

temperature (+ 10*C =2x - 4x), oxygen concentration, soil conditions, light, plant growth

Question 23

what is NAR

Answer 23

net assimilation rate= photosynthetic gains - respiration losses

Question 24

what must happen for plant growth to occur

Answer 24

the NAR must be positive (more energy gained than lost)

if respiration exceeds photosynthetic gains (NAR is negative) then plants will eventually die

factors that determine NAR include the factors that affect photosynthesis and respiration rates

Question 25

how much percent of the suns energy is captured by plants

Answer 25

0.1% to 3% with an average of 2%

Question 26

what is the leaf area index (LAI)

Answer 26

it is a ratio of leaf area to land area

3 hecteres leaf are / 1 hectare lan =3 LAI

only the leaf area that is exposed to the sun is counted (not the underside of the leaf)

each crop has its own LAI optimum (2 to 5 usually)
below optimum photosynthetic rate is limitied
above optimum shading is occurring and the NAR is reduced because shaded leaves perform respiration