metabolism
chemical process that occurs within organisms to maintain life
metabolic pathway
A series of chemical reactions that builds complex or breaks complex molecules
Catabolism
breakdown process of complex molecule to simpler (release NRG)
Anabolism
building process of smaller molecules to larger ones
Bioenergetics
study of how energy flows through living organisms
energy
capacity to cause change
kinetic energy
energy related to relative motion of molecules
thermal energy
kinetic energy associated with random movement of atoms/molecule
Potential energy
possessed energy not moving, by molecule or atom
Chemical energy
potential energy available for release in chemical reaction
Thermodynamics
study of energy transformation that occurs in collection of matter
1st law of thermodynamics
energy of universe is constant (not created/destroyed)
2nd law of thermodynamics
energy transfer increases entropy of universe (energy lost as heat)
entropy
measure of randomly collected matter/energy (disorder of energy) (randomness)
spontaneous process
time-evolution of system regarding energy states
free energy
portion of system energy that can perform work
exergonic reaction
reaction that proceeds net release of free energy
endergonic reaction
reaction that absorbs energy from surroundings
chemical work
pushing of endergonic reactions
transport work
pumping substances across membrane (against conc. gradient)
mechanical work
using energy to contract cells, move chromosomes, etc.
energy coupling
way cells manage resources using exergonic process to drive endergonic one
Phosphorylated intermediate
recipient molecule in process that contains phosphate group covalently bonded
Enzyme
organic substance (protein) that acts as catalyst to bring about a specific biochemical reaction
Isomerase
makes isomers flip
Kinase
adds phosphate
Dehydrogenase
big hydrogen remover
Catalyst
chemical agent that speeds up chemical reaction without being consumed
Activation energy
energy required to contort reactant molecule to break bonds
Substrate
reactant an enzyme acts on
Enzyme-substrate complex
complex of substrate attached to enzyme's active site
Active site
location on enzyme where substrate binds to
Induced fit
model that idealizes the interaction of substrate and enzyme
Cofactor
helpful non-proteins for catalytic activity
Coenzyme
organic cofactor
Competitive inhibition
inhibition mimicking substrate and blocks active site, competing with substrate
Non-competitive inhibition
inhibition where chemicals bind to allosteric site and changes the structure of active site (substrate concentration does not affect)
Temperature
variable that break bonds (H-bonds) at high levels and not enough energy at low for enzyme reactivity
pH
variable that can cause denaturation in enzymes (level of H+ ion concentration)
Salinity
affects side chains because clogged by ions
Inhibitors
non-comp or comp
Activators
binds to site & facilitates substrate conversion (copper)
Allosteric regulation
The binding of a (regulatory) molecule to a protein at a site that affects the function of the protein at a different site
Cooperativity
amplification of response of enzyme to substrate - a type of allosteric regulation
Feedback inhibition
metabolic pathways halted by inhibitory binding of end product to an enzyme earlier in pathway
ATP
nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed. This energy is used to drive endergonic reactions in cells
Fermentation
catabolic process where partial degradation of sugars or other organic fuel occur without the use of oxygen
Aerobic respiration
efficient metabolic process where oxygen is used as final electron carrier
Cellular respiration
catabolic pathways of aerobic/ anaerobic respiration - break down of molecules and use of ETC to make ATP
Redox-Reaction
transfer of electrons with reduction and oxidation reactions
Reducing agent
The electron donor in a redox reaction.
Oxidizing agent
The electron acceptor in a redox reaction.
Nicotinamide adenine dinucleotide
NAD(H)" coenzyme electron carrier
Flavin adenine dinucleotide
FAD(H2)" redox cofactor electron carrier
Nicotinamide adenine dinucleotide phosphate
NADP(H)" cofactor electron carrier from water
ETC
electron transport chain, a sequence of e- carrier molecules that shuttle e- down series of redox reactions for release of energy for ATP production
Glycolysis
series of reactions that ultimately split glucose into pyruvate and occurs in cytosol of almost all cells
Citric acid cycle
chemical cycle where oxidation of acetyl CoA from pyruvate is turned into CO2
Oxidative phosphorylation
production of ATP from redox reactions of ETC chain, 3rd major stage of cellular respiration
Substrate-level phosphorylation
enzyme catalyzed formation of ATP by direct transfer of p-group to ADP (from substrate)
Acetyl CoA
entry compound for citric acid cycle in cellular respiration formed from 2C fragment of pyruvate attached to a coenzyme
Ribulose 1,5-bisphosphate carboxylase oxygenase
Rubisco" - enzyme in plant chloroplasts, that fixes CO2 during photosynthesis
Reduction
The complete or partial addition of electrons to a substance involved in a redox reaction.
Regeneration of CO2 acceptor
carbon skeleton of 5 molecules of G3P are rearranged by spending 3 ATP; the RuBP is then ready to receive CO2 again
C3 Plants
plant that uses CC for initial steps that incorporate CO2 into organic compounds, forming 3C compound as first stable intermediate
C4 Plant
plants that use CC after reaction that incorporates CO2 and decreases photosynthetic output...generally occurs in hot environments; O2 ratio rises due to stomata closing
Photorespiration
metabolic pathway that consumes O2 and ATP, releasing CO2 into organic compounds, forming 3C compound as first stable intermediate
Bundle-sheath cells
type of photosynthetic cell in C4 plants arranged into tightly packed sheaths around the veins of a leaf
PEP Carboxylase
enzyme that adds CO2 to phosphoenolpyruvate (PEP) to form oxaloacetate in mesophyll cells of C4 plants prior to photosynthesis
CAM
crassulacean acid metabolism" adaptation for plants in arid conditions; stomata open at night for CO2 to be made into organic acids (no light), and close during day (light)
CAM plant
plants that use "crassulacean acid metabolism" in arid conditions. Here, CO2 enters plant @ night (stomata open) and are turned into organic acids, which then release CO2 for the CC during the day (stomata closed) store organic acids in vacuole
ubiquinone
first electron transfer agent in ETC
cytochrome c
enzyme (protein) with iron that is component of ETC in mitochondria and chloroplast of eukaryotic cells and plasma membrane of prokaryotic cells
plastoquinone
pq" first electron transfer agent in light reaction
plastocyanin
pc" second electron transfer agent in light reaction
ferodoxin
fd" third electron transfer agent in light
flavin mononucleotide
fmn" protein where NADH comes in ETC
iron sulfur protein
fes" protein where FADH2 enters in ETC