Autotroph
Organism that can capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds.
Photosynthesis
The conversion of light energy to chemical energy that is stored in glucose or other organic compounds; occurs in plants, algae, and certain prokaryotes.
Heterotroph
Animals and other organisms that must get energy from food instead of directly from sunlight or inorganic substances.
Light Reactions
First stage of photosynthesis. Named Because it requires light to happen. Begins with the absorption of light in the Chloroplasts.
Chloroplast
Organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy.
Thylakoid
A membrane system found within chloroplasts that contains the components for photosynthesis.
Granum
A stack of thylakoids in a chloroplast.
Stroma
in plants, the solution that surrounds the thylakoids in a chloroplast
Pigment
A colored chemical compound that absorbs light, producing color.
Chlorophyll
Any of a group of green pigments found in the thylakoids of the Chrloroplasts.
Carotenoid
Other compounds found in the thylakoid, functions as a accessory compound.
Photosystem
in plants a unit of several hundred chlorophyll molecules and carotenoid pigment molecules in the thylakoid membrane
Primary Electron Acceptor
a molecule in the thylakoid membrane that accepts the electrons that clorophyll (a) loses in the light reactions
Electron Transport Chain
molecules in the thylakoid membrane or inner mitochondrial membrane that uses some of the energy in electrons to pump protons across the membrane
Chemiosmosis
in chloroplasts and mitochondria, a process in which the movement of protons down their concentration gradient across a membrane is coupled to the synthesis of ATP
Calvin Cycle
a biochemical pathway of photosynthesis in which carbon dioxide is converted into glucose using ATP
Carbon Fixation
The incorporation of CO2 into organic compounds.
Stomata
Small pores on the underside of leaves.
CAM Pathway
Crassulacean Acid Metabolism, water-conserving pathway.
accessory pigment
a pigment that absorbs light energy and transfers energy to
adenosine diphosphate (ADP)
a substance involved in energy metabolism
ATP synthase
an enzyme that catalyzes the synthesis of ATP from ADP and
biochemical pathway
a series of chemical reactions in which the product of
C3 plant
a plant that fixes carbon exclusively through the Calvin cycle, named
C4 plant
a plant that incorporates CO2 into four-carbon compounds
NADP+
nicotinamide adenine dinucleotide phosphate; an organic molecule that
PGA
phosphoglycerate; a three-carbon molecule formed in the first step of the
PGAL
glyceraldehyde phosphate; a three-carbon molecule formed in the
visible spectrum
the portion of sunlight perceived by the human eye as various colors
wavelength
the distance between crests in a wave
_________ converts light energy from the sun into chemical energy in the form of organic compounds through a series of reactions known as _______________.
photosynthesis; biochemical pathways
___________ use energy from sunlight or from chemical bonds in inorganic substances to make organic compounds.
autotrophs
Animals and other organisms that must get energy from food instead of directly from sunlight or inorganic substances are called _________.
heterotrophs
Are humans heterotrophs or autotrophs?
heterotrophs
The oxygen (O2) and some of the organic compounds produced by photosynthesis are used by cells in a process called ____________.
cellular respiration
Photosynthesis can be divided into two stages that are ________ and ___________.
light reactions; Calvin cycle
In the ____________, light energy is converted to chemical energy, which is temporarily stored in ATP and the energy carrier molecule NADPH.
light reactions
Autotrophs are mostly ______.
plants
The ____ is the main source of energy.
sun
In the _______, organic compounds are formed using CO2 and the chemical energy stored in ATP and NADPH.
Calvin Cycle
What is the equation for photosynthesis?
6CO2 + 6H2O light energy C6H12O6 + 6O2
What does 6CO2 mean?
carbon dioxide
What does 6H2O mean?
water
What does light energy mean?
light
What does C6H12O6 mean?
glucose sugar carbohydrates
What does 6O2 mean?
oxygen
The light reactions begin with the absorption of light in __________.
chloroplasts
organelles found in the cells of plants, some bacteria, and algae
chloroplasts
White light from the sun is composed of an array of colors called the ______________.
visible spectrum
_________ absorb certain colors of light and reflect or transmit the other colors.
pigments
A green plant absorbs every color except _______ which is what is reflected back.
green
Located in the membrane of the thylakoids of chloroplasts are several pigments, including ____________________.
chlorophyll a, chlorophyll b, and carotenoids
Chlorophyll a, chlorophyll b, and carotenoids are pigments located where?
thylakoid membrane
Chlorophyll a absorbs less ____ light but more _____.
blue; red
Chlorophyll b absorbs less ______ than chlorophyll a.
light
Neither chlorophyll a or chlorophyll b absorb much _____.
green
Green is _________ or ____________.
reflected; transmitted
Only ___________ is directly involved in the light reactions of photosynthesis.
chlorophyll a
____________ helps chlorophyll a in capturing light energy.
chlorophyll b
____________ is an accessory pigment.
chlorophyll b
Carotenoids are ___________.
accessory pigments
What colors do carotenoids (accessory pigments) show?
yellow, orange, and brown
The pigments are grouped in clusters of a few hundred molecules in the ___________.
thylakoid membrane
Each cluster and the proteins that the pigment molecules are embedded in are referred to collectively as a _____________.
photosystem
By absorbing light, pigment molecules in __________ and __________ acquire some of the energy carried by the light.
photosystem I; photosystem II
In each _________, the acquired energy is passed quickly to other pigment molecules until it reaches a specific pair of _________ molecules.
photosystem; chlorophyll a