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Flashcards in Chapters 8-10 Deck (68)
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All chemical processes that occur within an organism. Energy is constantly being traded


Catabolic pathways

Break large molecules into smaller ones, releasing energy in the process


Anabolic pathways

Build larger molecules from less complex ones, requiring energy input



Capacity to do work


First Law of Thermodynamics

Energy can not be made nor destroyed only change shape


Second law of thermodynamics

All natural processes proceed in the direction if increasing entropy



Randomness or disorder (if you don't clean your room it will only get messier)


Characteristics of Heat

Most entropic form of energy and is produced in every step of energy transfer between organisms (often "lost to environment")


Exergonic reaction

Reactions that release energy


Endergonic reaction

Reactions capture energy in cell


Coupled reactions

Exergonic reactions provide energy for endergonic reactions



A class of protein catalysts that lower the activation energy needed to get a chemical reaction going in cells


Structure of enzyme

3-dimensional and have an active site to which substrates bind to allow the reaction to occur. Each enzyme carries out a very specific function

Enzymes are not altered permanently and can be recycled

Each enzyme has an optimal temperature and pH to function


Cell wall

Limits water movement, maintains cell shape, protection. Cellulose is bonded with lignin for strength.


Central vacuole

Large vacuole in center of cell containing approximately 95% water, where digestion and metabolism occurs. Stores waste and pigments (in some red and blue flowers). Usually 1 or 2 central vacuoles per cell and may comprise 90% of cell volume.



Organelle that gathers or stores food or contains pigments
Ex. Chloroplast and chromoplast



Contains chlorophyll


Where does the light-dependent reaction take place?

In the thylakoid membrane


What wavelength does Photosystem I best work at?

700 nm


What wavelength does Photosystem II best work at?

680 nm


What happens for for light-dependent reaction to produce more ATP?

Cyclic electron flow sends electron from primary acceptor of Photosystem I back to cytochrome complex.


How does the primary acceptor replenish its electron?

Water is broken into hydrogen and oxygen. The electron is stripped into ions and electrons and the ions are out into the thylakoid space. The oxygen is released as waste


How is NADPH created?

NADP+ floating in stroma from the Calvin cycle is combined with the electron from Photosystem I to make NADPH. NADP+ is the final electron acceptor on the electron chain.


First phase of Calvin Cycle

Carbon fixation. 3 molecules of CO2 are attached to 3 molecules of Ribulose Biphosphate (RuBp) a 5-carbon molecule. Each of the six-molecules break in half and form 3-PGA, which has 3 carbon atoms.


Phase 2 of Calvin Cycle

6 molecules of ATP produced in the light-dependent reaction put a phosphate on the 6 3-PGA molecules. NADPH adds two electrons to each. This makes G3P and one of the 6 molecules leaves the cycle. Phase 2 is called reduction.


Phase 3 of Calvin cycle

5 remaining G3P go on to be regenerated. The 5 G3P (15 carbon atoms total) are rearranged with 3 ATP molecules and some other steps to make 3 5-carbon RuBp molecules.


Why is c3 photosynthesis ineffective?

Enzyme rubisco is only 75% effective because it sometimes picks up oxygen instead of carbon dioxide. On hot days stomata will close and this will cause Rubisco to make more mistakes as the oxygen level increases and carbon dioxide decreases.


Examples of c4 plants and how they differ?

An acid cycle and the Calvin cycle are separated spatially. The acid cycle takes place in the spongy and palisade mesophyll cells and the Calvin cycle takes place in the bundle sheath cells. The acid cycle uses an enzyme called PEP to pump carbon dioxide in the form of a 4-carbon chain Malate into the Calvin cycle. Examples of c4 plants include corn, sugar cane, crab grass.


Explanation of CAM plant?

Temporally separated acid cycle and Calvin cycle. In the night time the stomata are opened and the CO2 is made into chains called crassulacean acid. During the day this acid is sent to rubisco in the Calvin cycle.


Epidermis structure and function

Single layer of cells used to slow water loss. Secretes waxy cuticle. Within the epidermis are stomata.