Name____________________________________________ Date_________________ Period________
Honors Living Environment
8th Grade Honors
Living Environment
Unit 4a (Photosynthesis) Study Outline
This handout will serve as a resource to help guide you in studying for the Unit 4
Quest (Photosynthesis). We encourage that you find a study method that works
best for you. Use this page as a reference as you review class notes, handouts,
quizzes, Castle Learning assignments, etc. In addition, there are excellent
resources on the internet that you can use for supplemental review and
reinforcement. Visit our teacher webpages for some suggestions on internet
sources. As always, come to extra help and to our review sessions if you have any
questions. Best of luck!
I.
II.
Nutrition
a. Autotroph
i. Make own food through process of photosynthesis
1. Takes place in the leaves of plants
a. takes place in the chloroplasts (organelle)
ii. Need water, carbon dioxide, and sunlight
iii. Make glucose (food) and oxygen (waste product)
b. Heterotroph
i. Get food from environment
ii. Ingestiondigestionegestion
Absorption of light
a. Visible light has many wavelengths
i. Different wavelengths are recognized as different colors (ROYGBIV)
b. Chloroplasts are green
i. Absorbs red and blue light very well
ii. Reflects green light
1. Our eyes detect wavelength of green light and our brain
processes it as green
c. Pigments- absorb certain wavelengths of light and reflect others
i. Chlorophyll
1. Chlorophyll a and chlorophyll b
ii. Accessory pigments- pigments other than chlorophylls (in much
smaller amounts than chlorophyll)
1. Carotenoids
2. Xanthophylls
3. Anthocyanins
iii. Chromatography-technique for separating pigments (must know
technique)
Name____________________________________________ Date_________________ Period________
Honors Living Environment
III.
Biochemistry of Photosynthesis
a. Equation
i. Chemical equation
1. Sunlight + 6 CO2 + 6H2O C6H12O6 + 6O2
ii. Word equation
1. Sunlight + carbon dioxide + water  glucose + oxygen
b. Chloroplast
i. Outer membrane
ii. Inner membrane
iii. Thylakoid
iv. Grana
v. Stroma
vi. Lumen
c. 2 main stages of photosynthesis
i. Light Dependent reactions
1. AKA- light reactions
2. Location-Thylakoid membrane
3. Inputs- sunlight and water
4. Outputs- NADPH & ATP (used in light-independent reactions),
O2 (waste product)
5. A more detailed look at light reactions…
a. In thylakoid spaces of the grana in the chloroplast.
b. Sunlight strikes the chlorophyll contained within the
thylakoid spaces which causes electrons to become
excited and infused with energy.
c. Electrons are transferred down an electron transport
chain.
d. The energy in the electrons is used to set up a proton
gradient across the membrane of the thylakoid spaces.
e. Protons flowing back across the thylakoid membrane
according to the concentration gradient are harnessed to
produce ATP and NADPH (the reduced form of NADP).
f. As a by-product of this process, molecules of water are
split into molecular hydrogen and oxygen (photolysis).
g. The plant needs the hydrogen to produce ATP.
h. The oxygen you’re breathing right now is some of that
waste product.
i. The purpose of the light reaction is to make the
usable energy necessary to run the lightindependent reaction.
ii. Light-Independent Reactions
1. AKA- dark reactions, calvin cycle, carbon fixation
2. Location- stroma
3. Inputs- NADPH & ATP (from light reactions), CO2
4. Outputs- glucose
Name____________________________________________ Date_________________ Period________
Honors Living Environment
5. A more detailed look at dark reactions…
a. The reaction takes place in the stroma of the chloroplast
b. In the dark reaction, the carbon from carbon dioxide is
added to the five-carbon sugar ribulose bisphosphate
(RuBP) to produce a six-carbon compound.
c. This unstable six-carbon sugar is immediately split into
two three-carbon molecules, which in a chain reaction
using the ATP and NADPH from the light reaction are
modified to form glyceraldehyde 3-phosphate (G3P).
d. The glyceraldehyde 3-phosphate can be synthesized into
carbohydrates such as glucose.
e. One of the glyceraldehyde 3-phosphate molecules is
made into carbohydrates, while the other molecules
remain in the Calvin cycle to serve as raw materials for
the next round of production.
d. Factors that affect photosynthesis (be familiar with relationships for each
factor)
i. Light intensity
ii. Carbon dioxide
iii. Temperature
iv. Water
v. Minerals
IV.
Plant Adaptations
a. Parts of leaf
i. Palisade mesophyll
ii. Spongy mesophyll
iii. Cuticle
iv. Stomata
v. Guard cells
1. Water regulation
a. Stomates open- water leaves plant, CO2 and O2 enter
leaf
b. Stomates closed- water does not leave, CO2 and O2
cannot enter
b. Transport
i. Vascular Tissue
1. Xylem- transports water
a. One direction (roots to leaves)
b. Root hairs
c. Root pressure
d. Capillary action
e. Transpiration
f. Transpiration pull
2. Phloem- transports nutrients
a. Both directions