anabolic reactions
forming bonds between molecules consuming energy to build complicated molecules from simpler ones
catabolic reactions
breaking bonds between molecules; breakdown pathways; like digestion(hydrolysis)
exergonic reactions
chemical reactions that release energy
endergonic reactions
chemical reactions that require input of energy
activation energy
the energy required to break bonds in the reactant molecules and start chemical reactions; must absorb energy to break bonds
Enzyme
a protein that reduces the activation energy of reactions in a cell, but is not used up in the reactions (acts as a catalyst) - speeds up a reaction
enzyme specificity
enzymes have a specific shape to specific chemical reaction (1 enzyme = 1 reaction type)
substrate
substance on which the enzyme acts; binds to enzyme according to shape
active site
enzymes catalytic site; substrate fits like a key into a lock
Denaturation
Destroying the function of a protein by changing its structure (can be done by changing temperature, pH, or salinity)
Induced Fit model
substrate binding causes enzyme to change shape and have tighter fit
Increasing Enzyme Concentration
more enzymes equals more frequently collide with substrate; equilibrium is reached when the amount of substrate equals the amount of enzyme
Increasing substrate concentration
More substrate equals more frequent collisions with enzymes; all enzymes have active site engaged; enzyme becomes saturated
inhibitors
molecules that reduce enzyme activity
competitive inhibtion
inhibitor competes with substrate for active site by binding in the active site and blocking the substrate
non-competitive inhibition
type of inhibition where an inhibitor binds to site other than active site causing enzyme to change shape; active site no longer functions
Allosteric regulation
when molecules bind somewhere other than the active site; cause a change in enzymes shape; can inhibit or activate
Feedback inhibition
the final product is in a metabolic pathway is an enzyme inhibitor for an earlier step
Cofactors
small inorganic compounds like Mg, K, Ca, Zn and other minerals; that increase the activity of enzymes
Coenzymes
non-protein organic molecules that bind temporarily or permanently to enzyme near active site; like many vitamins
Allosteric Inhibitor
a molecule that binds to allosteric site and reduces enzyme activity
Allosteric activator
a molecule that binds to allosteric site and increases enzyme activity
Enzyme cooperativity
A substrate molecule bound to an active site of one subunit promotes substrate binding to the active site of other subunits.
Metabolism
All of the chemical reactions that occur within an organism
Entropy
A measure of disorder or randomness.
energy coupling
The use of an exergonic process to drive an endergonic one.
Autotroph
An organism that makes its own food
Heterotroph
organism that obtains energy from the foods it consumes; also called a consumer
Oxidation
loss of electrons (or hydrogen)
reduction
gain of electrons (or hydrogen)
Phosphorylation
the addition of a phosphate group to a molecule
Chemiosmosis
making ATP using the energy from a hydrogen ion concentration gradient and the ATP synthase enzyme.
ATP synthase
The enzyme that makes ATP from ADP and inorganic phosphate.
reactants of cellular respiration
glucose and oxygen
reactants of photosynthesis
carbon dioxide and water
products of cellular respiration
carbon dioxide, water, and ATP
products of photosynthesis
glucose and oxygen (products)
Glycolysis
breakdown of glucose into pyruvate; produces small amount of ATP; no oxygen required
location of glycolysis
cytoplasm
location of citric acid cycle
matrix of mitochondria
products of the citric acid cycle
NADH, FADH2, CO2, some ATP
location of electron transport chain
inner mitochondrial membrane (cristae)
cellular respiration electron carriers
NAD+/NADH and FAD/FADH2
photosynthesis electron carriers
NADP+ to NADPH
Products of cell respiration Electron Transport Chain
water and lots of ATP
final electron acceptor in cell respiration
Oxygen
Fermentation
Process by which cells release energy in the absence of oxygen
products of fermentation
ethanol and lactic acid
inputs of light reactions
light, water, ADP, NADP+
products of light reactions
ATP, NADPH, O2
location of light reactions
thylakoid membrane
location of Calvin cycle
stroma
Inputs of Calvin Cycle
CO2, ATP, NADPH
Main Product of Calvin Cycle
G3P (used to make sugars like glucose)
CAM plants
plants close their stomata during the day, collect CO2 at night, and store the CO2 in the form of acids until it is needed during the day for photosynthesis
ATP production in both cell respiration and photosynthesis
electron transport chain and chemiosmosis
C4 plants
separate the reactions in photosynthesis by running the light reactions and the Calvin Cycle in different cells
C4 and CAM plants
plants that have adapted to hot, dry conditions
Role of pigments in photosynthesis
absorb light energy at specific wavelengths