Biology 100 Unit 7 Flashcards
Plants are _________ as are some bacteria and protisis
photosynthetic autotrophs
-Autotrophs have the ability to
make their food via photo synthesis
During photosynthesis plants take in atmospheric CO2 through opening in their leaves called ________________ water is absorbed through plants roots
stomate
water _________ and as it exits through the __________ and such water up through the _________ this process is referred to as
evaperates, leaves, roots, transpiration
photosynthesis equation
6CO2+6H20-> C6H12O6+6O2
during transpiration water travels using _________ to plants
vascular cells
As water travels through vascular of transpiration is the transfer of nutrients, photosynthesis produces
nutrients glucose
photosynthesis occurs in
chloroplasts
contain light absorbing pigments called _____________ which is involved in converting solar energy into chemical energy
chlorophyll
chloroplasts contain folded interconnected membranous sacs called
thylakoids
thylakoids form stacks called
grana
Chloroplasts are found in high concentration in the ____________ (middle tissue) of a lead
mesaphyll cells
is the process by which autotrophic organisms convert light into chemical energy
photosynthesis
although chloroplasts can be found in multiple types of plants tissue
they are most abundant in the leaves of plants
guard cells regulate the opening of a
leaves stomata
has two parts, the light reactions and the dark reactions
photosynthesis
energy from light drives the synthesis of
ATP and NAPDH (electron carrier)
during the calvin cycle:
________: is required to synthesize sugar
ATP
during the calvin cycle:
________: important to synthesize sugar
NADPH reduces CO2
synthesis of ATP and acquisition of an e-
Light reaction
uses ATP and reduced CO2 to form glucose
dark reaction
light consists of high speed particles called
photons
photons are packets of
electromagnetic energy
The electromagnetic spectrum shows the full range of
radiation types
Short wave length -> __________________
Long wave length -> ___________
high energy
low energy
absorb specific electromagnetic wavelengths and convert them to chemical energy
chloroplasts
contain different pigments to pick up different wavelength
chloroplasts
the most important pigment in green plants is
chlorophyll
_________ collides with pigment molecules inside the chloroplasts which absorbs some of the energy
visible light
Once pigments absorb photons:
-that energy splits
e- then move from ground state to an excited state
the electrons are then harnessed in a network of pigments referred to as a
photosystem
chlorophyll absorbs photons increasing
energetic states of an e-
after H2O is split, e- become energized and transfer to different pigment molecules until they reach a _________
reaction center
once e- reaches the reaction center they can become energized and bump up to a
primary electron acceptor
is a molecular light-capture device
-a pigment supported by other molecules receives an energy boost by the impact of photons
photosystem
After e- interact with the primary electron acceptor in the water-splitting photosystem (Photosystem II), they can travel to the NADPH producing photosystem (Photosystem I) via an electron transport chain
2nd: Once they enter the NADPH producing photosystem, e- can re-energize again (higher energy state) to another Primary electron acceptor
3rd: e- can then reduce NADP+ to NADPH, acting as a high energy electron carrier
NADPH-producing photosystem
two sequential photosytems are needs to complete
light reactions
two electron transport chains act during
light reactions
Carbon enters as CO2 and gets fixed to a 5 carbon compound called RuBP (Rubulose bisphosphate), this then breaks down into two 3-carbon molecules
- EnzymesuseATP&NADPHe-tothe3-carbonmolecule into G3P (glyceraldehyde 3-phosphate)
- Plants use G3P made in the Calvin cycle to make glucose, other G3P molecules continue in the Calvin cycle
- After sugar is made, any left over G3P molecules are used to regenerate more RuBP, which can fix more CO2 molecules
making sugar from CO2
least efficicient at producing glucose
C3 plants
calvin cyle uses co2 directs from air. Co2 intake is reduced decreasing
photostigmatic rates
they store CO2 into a 4-carbon molecule, which can supply the Calvin cycle with carbon to produce sugar even when stomata are closed during hot and dry conditions.
•Ex: sugarcane & corn
C4 plants
opens stomata at night only, and closes
them during the day to prevent water loss
– They also store CO2 in a 4-carbon molecule which can supply the Calvin cycle with carbon to produce glucose during the day
– Ex: pineapples, cactus, & succulent plants
CAM plants
operates on a global scale.
– Solar radiation includes visible light that penetrates the Earth’s atmosphere and warms the planet’s surface.
– Heat radiating from the warmed planet is absorbed by gases in the atmosphere, which then reflects some of the heat back to Earth.
– Without the warming of the greenhouse effect, the Earth would be much colder and most life as we know it could not exist.
the green house effect
The gases in the atmosphere that absorb heat radiation are called greenhouse gases. These include
- water vapor
- C02
- Methane
Increasing concentrations of greenhouse gases have been linked to ________________(also called global warming), a slow but steady rise in Earth’s surface temperature.
global climate change
Since 1850, the atmospheric concentration of CO2 has increased by about 40%, mostly due to the combustion of fossil fuels including
coal
oil
gas
The predicted consequences of continued warming include
melting of the polar ice caps -rise in water levels -extreeme weather drought increased extinction rates, and – the spread of tropical diseases.
Global warming caused by increasing CO2 levels may be reduced by
-limiting deforestation
-reducing fossil fuels
– growing biofuel crops that remove CO2 from the atmosphere.
