Ch.10 Energy Metabolism: Photosynthesis
Order
Less orderly
More orderly #
Entropy
prokaryotes
protists
fungi
plants
animals
absorbs scattered molecules
Co2
H20
minerals
organizes into organic molecules
death of organisms results in increase of entropy
accomplished by putting energy into living system
sunlight
maintains and increases orderliness
directly (photosynthesis)
indirectly (respiration)
Heterotrophs
Photoautotrophs
gather energy directly from light
all green plants
all cyanobacteria
few bacteria
take in organic molecules and respire
all animals
all completely parasitic plants
all fungi
nonphotosynthetic prokaryotes
Concepts
Energy Carriers
Energy and Reducing Power
energy enters biological world through photosynthesis
allow the energized pigments to make one or several smaller/less energetic/easily controlled intermediates
allow pigments to enter every reaction neccessary
not very mobile
too energetic
energized pigments are large molecules
guanosine triphosphate
ATP
ADP to ATP
substrate-level phosphorylation
oxidative phosphorylation
photophosphorylation
Reducing Power
Oxidized
an atom does not carry as many electrons as it could
oxidation state
Reduced #
electrons are added to an atom
reduction reaction
oxidation reaction
increases positive charge
reduces positive charge
oxidized compounds
often contain a lot of oxygen
reduced conpounds
often contain hydrogen
organisms need reducing power
ability to force electrons onto compounds
oxidizing agents
NAD+ and NADP+
reducing agents
NADH and NADPH
redox potential
tendency to accept or donate electrons
Other electron carriers
plastoquinones
plastocyanin
cytochromes
Photosynthesis
process that uses light to synthesize something
combination of CO2 and H2O to form carbohydrate
stroma reactions
light dependent reactions
aka dark reactions
aka thylakoid reactions
Light
pigments
electromagnetic radiation spectrum
infrared light
microwaves
ultraviolet light
radio waves
X rays
visible light
gamma rays
radiation
set of particles
quanta / quantum
photons
set of waves
materials absorb certain wavelengths more than others
any substance that absorbs certain wavelengths specifically and therefore has a distinct color is a pigment
chlorophyll a
Box 10-1 Global Climate Change
activation
when one quanta is absorbed by a pigment
ground state
excited state
fluorescence
release of light by a pigment
absorption spectrum and action spectrum
accessory pigments
carotenoids and chlorophyll b
Photosystems
Photosystem II
Photosystem I
resonance
antenna complex
reaction center
photosynthetic unit
little chlorophyll b
levels of chlorophyll a and b are equal
P700
ferrodoxin
ferredoxin-NADP+ reductase
reduces P700 system
efficiently produces NADPH
cytochrome b6/f complex
Q
plastocyanin
phaeophytin
P680
electron transport chain
Synthesis of ATP
grana / granum
frets
chemiosmotic phosphorylation
thylakoid lumen
cyclic electron transport
ATP synthase
noncyclic electron transport
CF0-CF1 complex
conversion of carbon dioxide to carbohydrate
aka Calvin/Benson Cycle
aka C3 cycle
takes place in stroma mediated by enzymes
First step
acceptor molecule (ribulose-1,5-biphosphate; RuBP)
3-phosphogylceraldehyde
3-phosphogylcerate
RuBP carboxylase (RUBISCO)
1,3-diphosphoglycerate
Anabolic Matabolism
anabolism
anabolic reactions
synthesis of polysaccharides
gluconeogenesis
anabolic synthesis of glucose
fructose-1,6-biphosphate
fructose-6-phosphate
dihydroxyacetone phosphate
glucose-6-phosphate
Environmental and Internal Factors #
Light
Leaf Structure
Water
C4 metabolism
Crassulacean acid metabolism
quality, quantity, duration
quality of sunlight
quality of light
light compensation point
duration of sunlight
C4 metabolism
PEP carboxylase
photorespiration
aka C4 photosynthesis
(phosphoenolpyruvate)
a second metabolic adaptation that improves conservation of water while permitting photosynthesis
Box 10-2 Photosynthesis in Bacteria and Cyanobacteria
Cross-link Description: Environmental and Internal factors limit a plant's ability to carry out photosynthesis. These factors include water, light, leaf structure, etc.
Cross-link description: The textbook notes, "a plant absorbs diffusely scattered molecules of carbon dioxide, water, and minerals and organizes them into organic molecules, cells, tissues, and organs."
Cross-link description: Photosystem II, the mechanism in which P700 is reduced, is just one example of reduction.