2 Flashcards
Metabolism
All of the chemical reactions that happen inside cells, including those that use and release energy
– Converts nutrients into usable energy for cellular processes
Metabolic Pathways
A series of connected chemical reactions where it begins with a specific molecule and ends with a product
Catabolic Pathways
Breaking down complex molecules into simpler ones by releasing energy
Anabolic Pathways
Creating complex molecules from simpler ones by inputting energy
Enzyme
Proteins that speed up chemical reactions
First Law of Thermodynamics
Energy cannot be created or destroyed, only transferred or transformed between forms
– The amount of energy in the universe will always be the same
Second Law of Thermodynamics
Entropy / disorder increases over time
– Energy naturally spreads out and became more disordered
Gibbs Free Energy
Usable energy in a system that can perform work
– Used to determine whether a reaction will happen spontaneously or need an energy input
– ΔG = ΔH − TΔS
Exergonic Reactions
Chemical reactions that releases energy and occurs spontaneously
–Have a negative Gibbs free energy (ΔG < 0) – meaning the reaction is spontaneous
Endergonic Reactions
Chemical reactions that requires an input of energy to proceed
– Will not take place on its own without adding free energy
– Have a positive Gibbs free energy (ΔG > 0)
Activation Energy
The minimum amount of energy required to start a chemical reaction
ATP
Energy-supplying molecule
Energy Coupling
The process of where energy from an exergonic reaction is used to drive an endergonic reaction
Active Site
The area on an enzyme where the substrate binds
Induced-fit Model
Theory that explains how enzymes bind to substrates
– When the substrate binds with the enzyme’s active site, the enzyme’s structure changes slightly to accommodate the substrate
Optimum pH
A pH that is too high (basic) or too low (acidic) can alter the change of the enzyme’s active site, causing it to change shape
– Most human enzymes work best around a neutral pH of 7
Competitive Inhibitors
Connects with the active site, preventing the substrate to connect
Non-Competitive Inhibitors
Connects with the allosteric site of the active site, which causes the active site to change shape which causes the substrate to not be able to connect to the enzyme’s active site
Feedback Inhibition
Uses a reaction product to regulate its own further production
Allosteric Inhibitors
A molecule binds to the allosteric site, causing the active site to change shape and stops the substrate from connecting to the active site
Allosteric Activators
A molecule binds to the allosteric site, changing the active site to better fit the substrate
Oxidation Reactions
Removing an electron from a substance
Reduction Reactions
Adding an electron to a substance
Redox Reactions
Chemical reactions in which electrons are transferred between substances
Electron Carrier
Compounds that store and transport energy, which can then be converted to other biochemical processes
Substrate-level Phosphorylation
Process where a phosphate group is directly transferred from a phosphorylated molecule (substrate) to ADP, forming ATP.
Oxidative Phosphorylation
A cellular process where energy from the oxidation (removal of elections) of nutrients is used to generate ATP
– Produces the most ATP
– Requires oxygen
– Occurs in the mitochondria
– Last step of cellular respiration
Cellular Respiration
Series of chemical reactions that break down glucose or other nutrients into carbon dioxide and water and the energy stored in the bonds of the nutrients are released.
– Has 3 steps
– An exothermic reaction (releases energy)
Anaerobic
Doesn’t use oxygen directly
Aerobic
Uses oxygen
Glycolysis
First step in the breakdown of glucose (a six-carbon sugar) to extract energy for cellular metabolism
Pyruvate
Three-carbon sugar
Outcomes of Glycolysis
– Starts with glucose
– Produces:
–Two pyruvate molecules (three-carbon molecule)
–Four ATP molecules
–Two ATP molecules are used in the first part of glycolysis, therefore net gain = two ATP molecules
–Two NADH molecules
Pyruvate Oxidation
Pyruvate molecules are transported into the mitochondria
– Only occur in eukaryotic cells, b/c only those have a mitochondri
Electron Transport Chain
Final state of aerobic respiration
H+
Proton
Lactic Acid Fermentation
Process in which glucose is broken down into energy without oxygen
– Produces lactic acid as a byproduct
Kinase
Enzymes that catalyze the transfer of phosphate groups from a high-energy phosphate-containing molecule (like ATP) to a substrate
Organic Compounds
Compounds that have carbon in it
Photoautotrophs
Organisms that use light energy to make their own food
Chemoautotrophs
Organisms that use chemical energy to make their own food
Heterotrophs
Organisms that cannot make their own food and get energy by consuming other organism
Epidermis
Outermost layer of the leaf
Stomata
Small pores located mainly on the underside of the leaf
Mesophyll
Tissue located between the upper and lower epidermis
Light-dependent Reactions
Energy from sunlight is absorbed by chlorophyll and the energy is converted into stored chemical energy
G3P
Type of sugar
Light Energy
