Exam 3 Flashcards
potential energy
the energy that matter possesses as a result of its location or spatial arrangement (structure)
Kinetic energy
the energy associated with the relative motion of objects. Moving matter can perform work by imparting motion to other matter
first law of thermodynamics
energy can neither be created or destroyed, energy can be converted from one form to another
second law of thermodynamics
disorder is more likely then order, entropy is increasing
all energy transformations proceed
spontaneously, more ordered to a less ordered, more stable to less stable, energy dissipates as heat
heat
random motions of molecules
anabolic pathways
metabolic pathway that consumes energy to synthesize a complex molecule from simpler molecules
catabolic pathways
a metabolic pathway that releases energy by breaking down complex molecules to simpler molecules
free energy
portion of a biological system’s energy that can perform work when temp and pressure are uniform throughout the whole system
activation energy
amount of energy that reactants must absorb before a chemical reaction will start
exergonic reactions
spontanious chemical reaction in which there is a net release of free energy
endergonic reactions
nonspontanious chemical reaction in which free energy is absorbed from the surrondings
Adenosine triphosphate
an adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolized. used to drive endergonic reactions
3 components of ATP
ribose, adenine, and phosphate groups
redox reactions
chemical reaction involving the complete or partial transfer of one or more electronsfrom one reactant to another
enzymes
macromolecule serving as a catalyst, chemical agent that increases the rate of reaction without being consumed by the reaction. most are proteins
coenzymes
organic molecule serving as a cofactor. most vitamins function as coenzymes in metabolic reactions
enzyme-substrate complex
temporary complex formed when an enzyme binds to its substrate molecule
active site
specific of an enzyme that binds the substrate and that forms the pocket in which catalysis occurs
four stages of aerobic respiration
glycolysis, pyruvate oxidation, krebs cycle, and electron transport chain and chemiosmosis
glycolysis
breaks down glucose and forms pyruvate with the production of two molecules of ATP
krebs cycle
series of chemical reactions, releases stored energy through the oxidation of acetyl-CoA derived from carbohydrates, fats and proteins into carbon dioxide and ATP
electron transport chain
compounds that transfer electrons from electron donors to electron acceptors via redox reactions, and couples this electron transfer with the transfer of protons (H+ ions) across a membrane.
where does glycolysis occur
cytoplasam
what does glycolysis breakdown
6 carbon glucose which 2 ATPs form it into a 6 carbon sugar diphosphate
6 carbon sugar diphosphate breakdown into
2 3 carbon sugar phosphates
Each 3 carbon sugar phosphate releases
an NADH and 2 ATPs and pyruvate
glycolysis is what process
catabolic process
major stages of glycolysis
priming, cleavage, and energy harvesting
pyruvate oxidation
releases CO2, produces NADH and acetyl coenzyme A, Acetyl coenzyme a is transferred to the mitochondria
where is the pyruvate oxidized
in the mitochondrial membrane from active transport
Acetyl CoA is a molecule that is further converted to
oxaloacetate
products of Krebs cycle
6 CO2, 4 ATP, 10 NADH, and 2 FADH2
what goes on in the electron chain
10 NADH and 2 FADH2
Oxaloacetate (4C) goes to
Citrate (6C)
Citrate (6C) goes to
ketoglutarate (5C)
ketoglutarate (5C) goes to
succinyl CoA (4C)
succinyl CoA (4C) goes to
succinate (4C)
succinate (4C) goes to
fumarate (4C)
fumarate (4C) goes to
malate (4C)
malate (4C) goes to
Oxaloacetate (4C)
how many turns does the krebs cycle make for each molecule of glucose
2
oxidative phosphorylation
occurs in the mitochondria, uses the energy released by electrons to pump H+ across the membrane, harnesses the energy of the H+ gradient through chemiosmosis producing ATP
anaerobic respiration
form of respiration using electron acceptors other than oxygen. Although oxygen is not used as the final electron acceptor, the process still uses a respiratory electron transport chain called physolmere; it is respiration without oxygen.
Cells are able to make ATP via
substrate level phosphorylation and oxidative phosphorylation
substrate level phosphorylation
transferring a phosphate directly to ADP from another molecule
oxidative phosphorylation
use of ATP synthase and energy derived from a proton (H+) gradient to make ATP
fermentation
use of organic molecules as final electron acceptor
alcohol fermentation
biological process which converts sugars such as glucose, fructose, and sucrose into cellular energy, producing ethanol and carbon dioxide as a side-effect.
lactate fermentation
metabolic process by which glucose and other six-carbon sugars (also, disaccharides of six-carbon sugars, e.g. sucrose or lactose) are converted into cellular energy and the metabolite lactate.
respiration equation
C6H12O6 + 6O2 -> 6CO2 + 6H2O
respiration occurs in
heterotrophs and autotrophs
photosynthesis occurs in
autotrophs
photosynthesis summary equation
6CO2 + 6H2O + light energy + chorllylful = C6H12O6 + 6O2.
photosynthesis is what process
redox, H2O is oxidized and CO2 is reduced
chloroplast structure
outer membrane, inner membrane surrounds the stroma and the grana (stacks of thylakoids). One thylakoid stack is called a granum.
2 main stages of photosynthesis
light-dependent reactions and light independent reactions
light-dependent reactions
capture energy from sunlight-make ATP and reduce NADP+to NADPH
light independent reactions
use ATP and NADPH to synthesize organic molecules from CO2
photoautotroph
sun so plants, algae, and cyanobacteria
chemoautotrophs
inorganic sources NH3, H2S and Sulfur
pigments
absorb visible light
Absorption spectrum
characteristic of each pigment Defines range & efficiency of light absorption
chlorophyl a and b pigments
green
Carotenoids
orange/yellow pigments accessory pigments
photosystem 1
light-capturing unit in a chloroplast’s thylakoid membrane or in the membrane of some prokaryotes; it has 2 molecules of P700 chlorophyll and at its reaction center
photosystem 2
one of the two light-capturing units in a chloroplast’s thylakoid membrane or in the membrane of some prokaryotes; it has 2 molecules of P680 chlorophyll an at its reaction center
What kind of light is best suited for photosynthesis?
indigo-blue and orange-red
chloroplasts split
water into hydrogen and oxygen
light reactions in thykaloid membrane
split water relasing O2 producing ATP and NADPH
Calvin cycle in the stroma
forms sugar from CO2 using ATP for energy and NADPH for reducing power
photon
a quantom or discrete quantity of light energy that behaves as if it were a particle
linear electron flow
during light reactions uses both photosystems and produces NADPH, ATP, and oxygen
cyclic electron flow
employs only one photosystem, producing ATP but not NADPH or O2
cytochrome complex
enzyme found in the thylakoid membrane in chloroplasts of plants, cyanobacteria, and green algae, that catalyzes the transfer of electrons
What is noncyclic photophosphorylation?
light-requiring part of photosynthesis in higher plants, in which an electron donor is required, and oxygen is produced as a waste product. It consists of two photoreactions, resulting in the synthesis of ATP and NADPH 2.
How many Photosystems are used in noncyclic photophosphorylation?
both
Light-dependent reactions occur in 4 stages:
primary photoevent, charge seperation, electron transport, and chemiosmosis
primary photoevent
photon of light is captured by a pigment molecule, splitting of water
charge seperation
energy is transferred to the reaction center; an excited electron is transferred to an acceptor molecule, photophosphorylation cyclic or non cyclic
electron transport
electrons move through membrane carriers to reduce NADP+ to NADPH
Chemiosmosis
produces ATP
calvin cycle
occurs in stroma, uses ATP and NADPH as sources of energy, turns CO2 into 3-PGA then RUBP then releases glucose
cyclic photophosphorylation
use of light energy to ultimately provide the energy to convert ADP to ATP, thus replenishing the universal energy currency in living things.
