Biology-Light Independent Reactions

Light independent reactions are also called what

Calvin-Benson Cycle

Where do light independent reactions occur

Stroma

carbon fixation

carbon atoms from CO2 are bonded into organic compounds (sugars)

What is the function of light independent reactions

set of reactions that produce "organic" compounds using Chemical energy produced during light dependent

What is the first step in the Process

Co2 enters the plant and diffuses into the stroma

What is the second step in the process

an enzyme combines with RuBP

What is RuBP

a five carbon carbohydrate

What does RuBP form

PGA (six carbon molecule that splits into a pair of three carbon molecule)

Why does it split

six carbons are too unstable

What is the third step in the process

PGA receives a phosphate from ATP and a proton from NADPH

What does this result in

results in ADP and NADP+ which can be used again in light-dependent reactions; PGAL also forms

What is PGAL

a three carbon sugar with higher energy bonds due to the P from ATP and the H+ from NADPH

What is the fourth step in light independent reactions

The resulting PGAL are used

How are the PGAL's used

by the plant cell to make sugar or to regenerate the five carbon compound RuBP

How many are used for food

One out of every six

How many are used to make RuBP

5 out of every 6

Where does the synthesis of sugars and other carbs occur

in the cytoplasm

Inputs

NADPH, ATP, CO2

Outputs

Sugars

White light

All the colors of the rainbow reflected

What are the two best colors for absorbing light

red and blue

What is the worst color for photosysthesis

green, because chlorophyll cannot absorb it

What are environmental factors that affect photosynthesis

Light intensity
CO2
Amount of water
Temperature
Humidity
Oxygen

How does humidity affect the opening and closing of the stomata

the more humidity the more open the stomates will be and vice versa

Graph of how light intensity affects photosynthesis

Graph of how CO2 affects photosynthesis

Graph of how much water affects photosynthesis

goes up then levels off

Graph of how temperature affects photosynthesis

25ºC is best

Graph of how humidity affects photosynthesis

goes up then levels off around 50%

Graph of how oxygen affects photosynthesis

slight downward slope