Photosynthesis
Photosynthesis: Step 1 – Light-Dependent ReactionSunlight is used to split water into hydrogen
(H) and oxygen (O). The Oxygen is released to the atmosphere.
Photosynthesis: Step 2 – Light-Independent
Reaction
This step is also called the Calvin Cycle or Light Independent Reaction because it does not need light.
CO2 combines with the hydrogen (H) released during step 1 to form C6H12O6 (glucose)
What affects the rate of photosynthesis?Amount of :- sunlight- CO2
- H2O
- temperatureAll the reactions of photosynthesis are controlled by enzymes. Temperatures above or below the optimum temperature will slow down the chemical reactions.
Pigments of Photosynthesis
Pigments are molecules that absorb specific wavelengths (energies) of light and reflect all others.
Chlorophyll is the main molecule in charge of capturing the energy from sunlight.
•Chlorophyll a absorbs …………….. light best.•Chlorophyll b absorbs ……………. light best.
•Why do plants look green?
•THEY RELFECT GREEN LIGHT!!!
Other Pigments Present in Plants
Carotenoids: Orange-Red
Xanthophyls: Yellow
Anthocyanins: Red-Blue
GET YOUR CLICKERS!
What is the process in which autotrophs trap the energy from the sun and store this energy in molecules such as carbohydrates.
1 2 3 4
0%
50%50%
0%
1. Predation2. Metabolism3. Cell Respiration4. Photosynthesis
Which of the following is not needed for photosynthesis?
1 2 3 4
0% 0%
17%
83%
1. Water2. Sugar3. Carbon Dioxide4. Sunlight
In addition to light and chlorophyll, photosynthesis
requires
1 2 3 4
3%
31%
66%
0%
1. Water and oxygen2. Water and sugars3. Oxygen and Carbon
Dioxide4. Water and carbon
dioxide
The leaves of a plant are green because chlorophyll :
1 2 3 4
0%
21%
79%
0%
1. Reflects blue light2. Absorbs blue light3. Reflects green light4. Absorbs green light
Which is not a function of NADPH?
To carry
energy for o
the...
To carry
2 high energy e...
To act as
a carri
er molecu
le
To carry
a hydrogen io
n
0% 0%0%0%
1. To carry energy for other organelles to do work
2. To carry 2 high energy electrons
3. To act as a carrier molecule
4. To carry a hydrogen ion
Chloroplasts do not contain which of the following
structures?
Mito
chondria
Thylakoids
Stro
ma
Chlorophyll
Pigments
75%
0% 0%0%
25%
1. Mitochondria2. Thylakoids3. Stroma4. Chlorophyll5. Pigments
10
Energy from the sun is collected during the:
Light-i
ndependent react.
..
Light-d
ependent reacti
ons
Thylakoid re
actions
Krebs C
ycle
25%
0%0%
75%1. Light-independent reactions
2. Light-dependent reactions
3. Thylakoid reactions
4. Krebs Cycle
10
Glucose is created during this step of photosynthesis.
Light-i
ndependent rea...
Light-d
ependent reacti
on
Thylakoid re
actions
Kre
bs Cyc
le
71%
6%18%
6%
1. Light-independent reaction
2. Light-dependent reaction
3. Thylakoid reactions
4. Krebs Cycle
10
Which of the following would not directly impact the growth of a plant?
Spectr
um of light
Concentra
tion of oxy
gen
Concentra
tion of carb
o...
Availabilit
y of water
Temperatu
re
6%
65%
18%
6%6%
1. Spectrum of light2. Concentration of
oxygen3. Concentration of
carbon dioxide4. Availability of water5. Temperature
10
Which of the following is NOT produced in the light-dependent
reactions?
NADPH
Suga
rs
Hyd
rogen Io
ns ATP
6%12%
18%
65%
1. NADPH2. Sugars3. Hydrogen Ions4. ATP
10