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Are producers of the biosphere


Produce their own food


Supply food for global ecosystem


use light energy to produce organic molecules


Plants, algae, and photosynthetic bacteria.


Double-layered organelle for photosynthesis. Has inner and outer membranes.


Fluid enclosed by inner membrane


Suspended in stroma, interconnected sacs, stacked in grana, contain chlorophylls (green pigments)


Makes sugar and O2 from CO2 and H2O

Calvin cycle

Synthesis part

Calvin Cycle

Occurs in stroma of Chloroplasts

Calvin Cycle

Produces sugar molecules from CO2 , ATP and NADPH

Calvin Cycle

Light energy is not necessary

Thylakoid membrane

Where do the Light reactions occur?

Light Reactions

Convert light energy to chemical energy: ATP and NAPH ( high energy intermediate)

red, orange, yellow, green, blue, indigo, violet

ROYGBIV is an abbreviation for what colors.

350-750 NM

Visible light range is?

750 NM

Low energy end = long wave length is what number of wavelength?

350 NM

High energy end = short wave length is what number of wavelength?


Light energy can be used.


light penetrates through object=color we see; energy NOT used.


Light bounces off object=color we see; energy NOT used.


molecules that absorb light


several pigments are built into _______ membrane?

Chlorophyll a

Reflects green light, absorbs blue-violet and red lights. Participates directly in light reactions

Chlorophyll b

Reflects yellow- green light, absorbs blue and orange lights. Conveys absorbed energy to Chlorophyll a.


Reflects yellow-orange light, absorb blue-green light. May pass energy to chlorophyll a


When pigment molecule absorbs a photon(solar energy). An electron is raised from ground state to excited state in what systems?

Ground state

an electron that is stable with low energy is at what state?

Excited state

an electron that is unstable with high energy is at what state?


An ________ electron rapidly drops back to ground state which releases heat


Some pigments may also emit _______light.


Includes several light harvesting complexes containing: chlorophyll, proteins and carotenoids


Photosystems include a __________ center that includes the chlorophyll A molecule and the primary electron acceptor

Chlorophyll a

A reaction center always contains what?

Photosystem 2



Absorbs photons

Photosystem 1

Delivers the Electron to the NADP+

Photosystem 1


Calvin Cycle

Input is carbon from CO2, NADPH and ATP.


these are used in light reactions


Most plants produce _____ in Calvin Cycle.

C3 plants

soybean, oats, wheat, rice


When weather is hot and dry, ________plant leaves close their stomata to conserve water. But CO2 entering plants is also decreased (plant yields are decreased).


When its hot and dry in _______ plants, CO2 is made into 4-carbon molecule in one cell type. Stomata are closed to conserve water. Then CO2 is released in another cell for Calvin Cycle to make sugar.


Plants make sugar through what process?

Light reactions

NADPH and ATP are produced during the _________

Thylakoid membrane

The location of the light reactions

ATP synthase

H+ flows through the ________ to create ATP

Calvin Cycle

GAL is produced in stroma (the liquid in the middle)

Global Warming

Greenhouse gases-water vapor, CO2, methane has to do with what?

Greenhouse effect

greenhouse gases can trap warm air around Earth more than usual the is called?

Global Warming

CO2 has increased 40% since 1850, causing what

Global Warming

Polar ice melting, extreme weather, rising sea levels, droughts all have to do with what?


This can reduce CO2 and global warming.

C6 H12 O6

Glucose's chemical formula


Enzyme vital to the success of the Calvin Cycle


Substrate of Rubisco


The reduction and oxidation of molecules is a way to transport what?


the organ in which photosynthesis occurs


CO2 enters, O2 leaves


___ is the bi-product of the light reactions

________ is the first to lose an electron in light reactions

Photosystem 1

hydrogen carrier


number of PGAL's devoted toward the regeneration of RuBP


organ of photosynthesis


organelle of photosythesis


smallest unit of life


pigment vital to photosynthesis

chlorophyll A

the only pigment that can "shoot" electrons

chlorophyll A

process in which water is split into hydroge and oxygen


stacks of thylakoids


chloroplasts are concentrated in the cells of the ________

palisades or mesophyll

willow tree experiment


consume other plants or animals or decompse organic material


selective permeability

a property of biological membranes, which includes the plasma membrane, that allows some substance to cross them more easily than others

cell membrane

membrane at the boundary of a cell that has a phospholipid bilayer that controls movement of molecules into and out of the cell; proteins are embedded into the phospholipid bilayer

amphipathic molecule

a molecule in which one side is hydrophobic and the other side is hydrophilic, as in phospholipids

fluid mosaic model

the current model of cell membrane structure that states that proteins are attached to/embedded in the fluid matrix of a phospholipid bilayer like a collage

10^7 (times per second)

speed of phospholipids' lateral movement within the membrane; flip-flopping across membrane is rare b/c of hydrophillic/phobic parts (~once per month)


a membrane in a higher temperature is more ______; a membrane that is unsaturated is also more _______. (vs. colder temperatures/saturation making the membrane more solid)


the steroid that is a "temperature buffer" for the membrane, lowering the temperature needed for it to solidify and making it less fluid at high temperatures

integral protein

membrane protein that penetrates the hydrophobic core of the lipid bilayer

transmembrane protein

integral protein that span the membrane

peripheral protein

membrane protein that are not embedded in the lipid bilayer but are bound to the surface of the membrane

major protein functions (in the plasma membrane)

1. transport 2. enzymatic activity 3. signal transduction 4. cell-cell recognition 5. intercellular joining 6. attachment to the cytoskeleton and extracellular matrix


one of the six major protein functions in the membrane; involves being a hydrophillic channel, a shuttle for substances, or a pump

enzymatic activity

one of the six major protein functions in the membrane; involves being a receptor/having an active site

signal transduction

one of the six major protein functions in the membrane; occurs when an external messenger fits and causes the protein to change shape and relay a message into the inside of the cell

cell-cell recognition

one of the six major protein functions in the membrane; where cells recognize other cells by binding to surface molecules, often carbohydrates (glycoproteins); short-lived

intracellular joining

one of the six major protein functions in the membrane; where proteins of adjacent cells bind together in junctions; long-lasting

attachment (to the cytoskeleton and ECM)

one of the six major protein functions in the membrane; binding to elements of cytoskeleton to maintain cell shape, stabilize locations of certain proteins, and coordinate cellular changes


membrane carbohydrates that are covalently bonded to lipids


membrane carbohydrates that are covalently bonded to proteins

supramolecule structure

many molecules ordered into a higher level of organization

transport protein

protein that allows passage of hydrophilic substances cross the cell membrane (because they can avoid contact with the lipid bilayer)

channel protein

a type of transport protein that has a hydrophilic channel


the channel protein that facilitates the passage of water through through certain cell membranes

carrier protein

a type of transport protein that binds to molecules in receptors and change shape to shuttle them across the membrane


the movement of molecules of any substance so that they spread out evenly into the available space

concentration gradient

diffusing from where it is more concentrated to where it is less concentrated is diffusing down a ______ ______

passive transport

diffusion of a substance across a membrane where the cell does not require energy to do so; because concentration gradient has potential energy


the diffusion of water across a selectively permeable membrane


the ability of a surrounding solution to cause a cell to gain or lose water, depends on concentration of solutes that cannot cross inside/outside the cell

isotonic solution

a solution with the same rate of diffusion in both directions across a cell membrane; stable

hypertonic solution

a solution in which there more solutes outside the cell, causing the water to rush out the cell, making it shivel; this environment causes problems for organisms

hypotonic solution

a solution in which there are less solutes outside a cell, causing water to enter faster than it leaves, making it lyse (burst); this environment causes problems for organisms


control of solute concentrations and water balance;
ex/ paramecium with a contractile vacuole


being very firm, the healthy state for most plant cells, occurs in a hypotonic solution when the cell swells until the cell wall opposes it


being limp, occurs when a plant's cell and its surroundings are isotonic


a phenomenon in a hypertonic environment when plant cells lose water and shrink and the plasma membrane pulls away from the wall

facilitated diffusion

diffusion in which transport proteins (like channel and carrier proteins) help speed the passive movement of molecules across the plasma membrane; no energy needed

ion channels

channel proteins that transport ions

gated channels

ion channels that open or close in response to a stimulus

active transport

the movement of solutes against their concentration gradients (low to high) by carrier proteins; needs energy/ATP; allows cells to maintain concentration different from surroundings

sodium-potassium pump

active transport system. 1) 3 Na+ binds to protein 2) ATP's phosphate for energy 3) Na+ released outside because of new shape 4) 2 K+ binds and releases phosphate from ATP 5) new protein shape 6) K+ is releasted again, ready for Na+


electrical potential energy, a separation of opposite charges

membrane potential

the voltage difference across a membrane, created by differences in the distribution of positive (outside) and negative (inside) ions; important for nerve cell/organ communication

70 mV

resting membrane potential (inside of cell is negative compared to outside)

electrochemical gradient

the diffusion gradient of an ion driven by a chemical force (the concentration gradient) and an electrical force (effect of membrane potential)

electrogenic pump

transport protein that generates voltage across a membrane
ex/ sodium-potassium pump in animals (net transfer of one positive charge)

proton pump

electrogenic pump of plants, fungi, and bacteria which actively transports hydrogen ions out of the cell; powered by ATP


when a single ATP-powered pump that transports a solute indirectly drives the active transport of another solute
ex/ plant cells uses H+ from proton pumps to actively transport sucrose against gradient


a process where transport vesicles migrate to the membrane, fuse with it, and release their contents to the outside of the cell


the process where the cell takes in macromolecules by forming vesicles from the plasma membrane; three types: phagocytosis, pinocytosis, and receptor-mediated


a type of endocytosis where the cell engulfs a particle with pseudopodia and packages it within a food vacuole


a type of endocytosis where the cell "gulps" droplets of extracellular fluid into tiny vesicles for the substances dissolved in the droplets

receptor-mediated (endocytosis)

a type of endocytosis where ligands bind to receptors on the membrane and trigger vesicle formation (coated pits → vesicles)


a term for any molecule that binds specifically to a receptor site on another molecule


the study of how organisms interact with their environment (Ch. 50)


nonliving (Ch. 50)


pertaining to the living organisms of the environment (Ch. 50)


the entire portion of Earth inhabited by life: the sum of all the planet's ecosystems (Ch. 50)

precautionary principle

a guiding principle in making decisions about the environment, cautioning to consider carefully the potential consequences of actions (Ch. 50)


the distribution of individuals within geographic population boundaries (Ch. 50)


large-scale variations in climate; the climate of an entire region (Ch. 50)


very fine scale variations of climate, such as the specific climatic conditions underneath a log (Ch. 50)


dead organic matter (Ch. 50)


a plot of the temperature and precipitation in a particular region (Ch. 50)


the uppermost layer of vegetation in a terrestrial biome (Ch. 50)


the transition from one type of habitat or ecosystem to another, such as the transition from a forest to a grassland (Ch. 50)


a type of learned behavior with a significant innate component, acquired during a limited critical period (Ch. 51)

sensitive period

a limited phase in an individual animal's development when learning of particular behavior can take place (Ch. 51)


a change in activity or turning rate in response to a stimulus (Ch. 51)


movement toward or away from a stimulus (Ch. 51)


the upper part of the moss capsule (sporangium) often specialized for gradual spore discharge (Ch. 51)


a very simple type of learning that involves a loss of responsiveness to stimuli that convey little or no information (Ch. 51)

spatial learning

modification of behavior based on experience of the spatial structure of the environment (Ch. 51)

classical conditioning

a type of associative learning; the association of a normally irrelevant stimulus with a fixed behavioral response (Ch. 51)