Bio Final Review Part 3 Flashcards
First Law of Thermodynamics
Energy in the universe is constant and can be changed from one form to another.
Energy cannot be created nor destroyed.
Second Law of Thermodynamics
Energy cannot be changed from one form to another without loss of usable energy.
Endergonic Reactions
Absorbs free energy from its surroundings.
Free energy increases
High capacity to change
Stable
Stores Energy
Non-Spontaneous
Anabolism
Exergonic Reactions
Proceeds with a net release of free energy
Free energy decreases
Low capacity to change
Unstable
Releases energy
Spontaneous
Catabolism
Entropy
The measure of disorder, or randomness.
Metabolic Pathway
Series of chemical reactions
Catabolism
Breaks down a complex molecule into smaller compounds.
Anabolism
Builds a complex compound.
Substrate
Molecules that react with the enzymes.
Active Site
The specific design of the enzyme for specific molecules.
Enzyme-Substrate Complex
Enzyme and substrate are combined to create a reaction.
With out an enzyme, a reaction will
take longer to occur
What are some factors that could affect enzyme activity?
Temperature and pH
Feedback Inhibition
The end product of a metabolic pathway shuts down the pathway,
End product can work to stop any activity.
Allosteric Regulation of Enzyme
Inhibit or stimulate the activity of an enzyme.
A molecule binds to a protein at one site and affects the protein’s function at another site.
Maintains homeostasis
Cofactors
inorganic nonprotein helpers
Coenzyme
Organic molecules, such as most vitamins.
Redox Reaction/Oxidation-Reduction Reaction
The movements of electrons from one molecule to another.
Oxidation
The loss of electrons from one substance
Reduction
The addition of electrons to another substance.
Substrate-Level Phosphorylation
An enzyme transfers a phosphate group from a substrate molecule to ADP and ATP is formed.
Glycolysis
Occurs in the cytoplasm.
Glucose is broken down (oxidized) and converted to pyruvate.
2 NET ATP
NAD+ —-> 2 NADH
2 pyruvate
Krebs Cycle
Occurs in the mitochondria
Completes breakdown of pyruvate to CO2
2 ATP
6 NADH
2 FADH2
Releases Oxygen
Oxaloacetate is the starting and ending product.
Oxidative Phosphorylation
Occurs in the mitochondria
NADH and FADH2 release hydrogen electrons. (NAD and FAD)
The electrons are transferred to protein complexes and electron carriers.
Electrons generate a proton gradient and protons are pumped across (through protein complexes).
Hydrogen protons will travel through an enzyme called ATP synthase.
Protons will give energy to the enzyme to power it and ass a phosphate group to ADP to create ATP.
Electrons will eventually get captured by oxygen and will create metabolic water.
28 ATP
Chemiosmosis
Any processes in which energy stored in a proton gradient is used to do work.
What are the electron carriers?
NAD and FAD
Fermentation
The partial degradation of sugars that occurs without O2
Enables cells to produce ATP without O2
Aerobic
Requires Oxygen
Anaerobic
Does not require oxygen
Lactic Fermentation
Glycolysis
2 pyruvate will yield 2 lactates.
2 pyruvate becomes a hydrogen electron acceptor allowing NADH to be oxidized to NAD+ so glycolysis begins again.
Alcohol Fermentation
Glycolysis
2 pyruvate is oxidized releasing O2
Acetaldehyde an electron carrier acts as an electron acceptor, picking up hydrogen electrons and transforming it to 2 ethanol.
Acetaldehyde picks up the 2 NADH and oxidizes it to NAD+ so glycolysis can begin again.
How is cellular respiration regulated?
Feedback inhibition
Pyruvate oxidation (mini step)
CO2 is released
NADH
Acetyl CoA
