Unit 2 - Metabolic Processes Flashcards
Just short definitions, draw diagrams and stuff
Metabolism
the sum of all chemical reactions that occur in the cell
Metabolic Pathway
a sequential series of chemical reactions in living cells; each reaction is catalyzed by an enzyme
Catabolism
process of breaking down compounds into smaller molecules to RELEASE energy
Anabolism
process of USING energy to build large molecules from smaller molecules
Endergonic
Chemical rxn that REQUIRES energy, energy has to go in, products have more energy than reactants
Exergonic
Chemical rxn that RELEASES energy, energy has to leave, products have less energy than reactants
Aerobic Cellular Respiration (definition, goal, NAME the stages)
C.R. includes the catabolic pathways that break down energy-rich compounds to produce ATP, requires oxygen, exergonic process, releases energy.
Goals: break glucose to get energy released in the form of ATP
Stages: Glycolysis, Pyruvate Oxidation, Krebs Cycle, Oxidative Phosphorylation
Substrate Level Phosphorylation (definition, what stages it occurs in)
Energy from the rxn of the substrate drives phosphorylation -> phosphate group is transferred to ADP to make ATP.
Occurs in Glycolysis and Krebs Cycle
Glycolysis (location, energy yield, starting molecule and ending molecule)
of rxns: 10
Location: Cytosol (in cytoplasm)
Anaerobic (does not require oxygen)
Net Energy: 2ATP, 2NADH
Start: glucose. End: 2 pyruvate
Pyruvate Oxidation (location, energy yield, starting and ending molecule)
Location: mitochondrial matrix
Requires oxygen
Net energy: 2NADH
Start: 2 pyruvate. End: 2 acetyl-coA, 2 CO2
Krebs Cycle (location, energy yield, input molecule)
Location: mitochondrial matrix
Requires oxygen
Net Energy: 2ATP, 6NADH, 2FADH
4CO2 also produced
Input: 2 acetyl-CoA
Oxidative Phosphorylation (location, purpose, energy yield, processes/structures involved)
Location: inner mitochondrial membrane
Requires oxygen
Couples the oxidation of electron carriers by the electron transport chain with the synthesis of ATP.
Net Energy: theoretically 36-38ATP
Structure: Electron Transport Chain
Process: Chemiosmosis
Electron Transport Chain (definition, function, structure)
Series of electron carriers and protein complexes, arranged in order of increasing electronegativity, embedded in inner mitochondrial membrane that accept and donate electrons in a series of rxns.
Proteins 1, 3, 5 are H+ pumps. Proteins 2, 4 are mobile electron carriers
-ETC is highly exergonic, free energy lost at each step is used to pump H+ out of matrix creating H+ ion gradient
-Oxygen is final electron acceptor, water is produced when O accepts the electrons and reacts with H+ ions. -The NADH made in glycolysis needs the GLYCEROL-PHOSPHATE SHUTTLE to move into the inner membrane and it changes to FADH2.
Chemiosmosis (explain process)
-energy from reduced electron carriers used to establish electrochemical gradient (Proton Motive Force)
-inner mitochondrial membrane is impermeable to H+ ions, so a high concentration of H+ ions builds up
-when H+ ions move along their gradient, through an ATP synthase complex, energy is released
-this energy is used to phosphorylate ADP into ATP
-ATP can then leave the membrane by facilitated diffusion into cytoplasm where it can drive endergonic processes
Anaerobic Respiration (definition)
When oxygen is not used as final electron acceptor, rather NO2, SO4, CO2, or Fe(III) is used.
Obligate anaerobes: die in presence of oxygen
Facultative anaerobes: tolerate oxygen or non-oxygen environment
Fermentation (definition, types)
Cells have limited supply of NAD+ so if no oxygen available:
organisms can recycle NAD+ by transferring H+ atoms of NADH to organ molecules.
Fermentation is less efficient at supplying energy since only the ATP generated in glycolysis is produced (2ATP).
Two common types: Lactate and Ethanol
Lactate Fermentation (process, function)
Some animal muscle cells function temporarily without oxygen
after glycolysis: pyruvate and NADH undergo REDOX rxn, NADH is oxidized, regenerating NAD+ for glycolysis. Pyruvate is reduced, becoming lactate/lactic acid.
Oxygen is ultimately needed to allow the lactate to be metabolized.
Alcohol Fermentation in Yeast (process, function)
Yeast and some bacteria are facultative anaerobes when there is no oxygen available, they convert pyruvate to ethanol and CO2.
CO2 leaves pyruvate which becomes acetaldehyde.
Acetaldehyde is reduced becoming ethanol, NADH is oxidized regenerating NAD+.
Used to manufacture baked goods, alcoholic drinks, and biofuels
Photosynthesis (definition, two main sets of rxns)
Uses/captures light energy and uses it to produce a carbohydrate (ie glucose). Enables plants to produce structural and metabolic substances that aid in their survival.
Two Main Sets of RXNS: light-DEPENDENT rxns, light-INDEPENDENT rxns
Thylakoid (structure, function)
A membrane system within a chloroplast forms interconnected disks that look like flattened pancakes.
Thylakoids absorb energy from the sun.
Pigment (function, location, main types)
Compounds that absorb certain wavelengths of visible light while reflecting others. In a leaf, photosynthetic pigments trap light energy and pass it along to other compounds like hot potato, pigments are embedded in thylakoid membrane.
Leafs look green bc chlorophyll molecules reflect green and yellow and absorb others.
More variety of pigments, more photosynthesis
Chlorophyll a - only pigment that can transfer the energy of light to the carbon fixation rxns of photosynthesis, passes energy to primary electron acceptor
Chlorophyll b- accessory pigment, absorbing photons that chlorophyll a absorbs poorly or not at all
Photosystems (structure, function, antenna complex)
protein-based complexes composed of clusters of pigments that absorb light energy. When a pigment absorbs a photon it passes the energy to chlorophyll a in form of excited electron.
combination of pigments and chlorophyll a is called the reaction center.
Antenna complex: accessory pigments gather energy from light so that the energy can be directed to rxn center.
Light Dependent Reactions (purpose, summarize three parts)
Purpose: make ATP and NADPH to fuel the Calvin Cycle
3 Parts:
1. Photoexcitation: absorption of photon by an e- of chlorophyll
2. Electron Transport: transport excited e- through e- carriers, causes H+ pumping through photosynthetic membrane creation of electrochemical gradient and eventual e- acceptor reduction
3. Chemiosmosis: ATP synthase complex causes PHOTOPHOSPHORYLATION (adp to atp)
(more indepth explanations in notes, too much for flash cards)
Light Independent Reactions
Calvin Cycle. Fix CO2 from inorganic to organic. Occurs in stroma. Can occur in presence or absence of light.
Three Phases:
1. Carbon Fixation: converts inorganic CO2 to organic Carbon, requires enzyme Rubisco, RuBP combines with CO2
2. Reduction Reactions: adding energy, activated by ATP, reduced by NADPH producing G3P, some regenerate RuBP, some exit to make glucose
3. Regeneration of RuBP: energy supplied by ATP to break and reform bonds to produce more RuBP.
6 times for 1 glucose
