AP Biology Chapter 6,7,8 Flashcards
What does the term energy mean?
The ability to do work or bring about a change
Explain why energy flows rather than cycles.
All captured solar energy eventually is lost as heat
State the first law of thermodynamics
Energy cannot be created nor destroyed, but it can be converted from one form to another.
How does the process of photosunth uphold the 1st law of thermodynamics
Uses solar energy to form carb molecules. some captured energy becomes heat
State the 2nd law of thermo”
Energy can’t be changed from on form to another w/o a loss of usable energy.
What is entropy and how does it relate to the second law of thermo”
Disorder in the universe. Every energy transformation makes the universe less organized.
How do channel proteins contribute to a cell’s entropy?
Distributes H+ ions evenly which creates more potential energy and more entropy.
Exp free energy
Energy that is still availaible to do work after a chem rxn occurs.
What is the diff bt exer and endergonic rxns
Exer- Neg. energy released
Ender - Pos. products have more free energy than rxtants
What molecule is the common energy currency of cells
ATP
Name the two comp that combine to regenerate ATP
ADP + P
What is the main nutrient molecule that provides the energy for building ATP
Glucose breakdown during cellular respiration
List the advan. of using ATP as an energy carrier in living systems.
Abundant source of energy, little waste
List and describe three types of work that use ATP energy
Chem - Energy needed to synth molecules
Mechanical - Muscle contractions, cilia and flagella movement, chromo’s moving
Transport - pump substances across plasma membrane.
Describe how an enzyme works
Substrate binds to active site, After rxn is complete, product is released, active site returns to original state.
Why is it sometimes necessary to block a metabolic pathway
Conserve raw material and energy
Competitive inhibition
substrate and inhibitor both able to bind to an enzyme
Non competitive inhibition
Binds to an enzyme at a location other than the active site (and allosteric site) that changes the shape
What is feedback inhibition
Final product of a pathway can inhibit an earlier rxn in the sequence.
inhibitors that can perm inactivate or destroy enzymes
Cyanide, mercury, and lead or penicillin.
What are auto trophs?
Photosynthetic orgs that produce their own food.
What are the three groups of photosynth orgs?
Plants, algae, and cyanobacteria
Describe the path H2O takes to get into a leaf’s chloroplasts
roots absorb water, the vascular tissue or leaf veins carry the water up and CO2 and water diffuse into cells and the chloroplast
Describe the path CO2 takes to get into a leaf’s chloroplasts
enters through the stomata, then diffuses into cells and then diffuses into chloroplasts.
Define pigments
Molecules that absorb wavelengths of light.
Photosynth pigs
Substances capable of absorbing solar energy
What info is gained from an absorption spectrum?
Shows which wavelengths of vis light are best absorbed by a pig to perform a fxn (photosynth)
What colors are best absorbed by chlorophyll a and b? Carotenoids?
A&B = Violet ish blue and red Carotenoids = violet, blue, green
Two main sets of rxns involved in photosynth and state where they occur in the chloroplast/ overall energy conversions
Light rxn: Thylakoid membrane/ Solar energy into chem energy (ATP, NADPH)
Calvin Cycle: Stroma/ Chem Energy (ATP, NADPH) into chem energy (Carb)
What are the comp of a photosys
Pigment comples with rxn center of chlor a/b / cateronoids) and e- acceptor molecules w/in a thylakoid membrane
What enzyme catalyzes bonding of ADP and P to produce ATP?
Atp Synth
The method of establishin an H+ gradient to produce ATP us called
Chemiosmosis
