Bio Chapter 5 Flashcards
Energy
The capacity to do work.
Glycolysis
The breakdown of glucose by enzymes.
Kinetic energy
The energy of motion.
First law of thermodynamics
Energy cannot be created or destroyed, but it can be transformed from one type to another [change from one form to another].
Entropy
Measure of how much energy of a system is dispearsed. Measure of energy that CANNOT be used [fake money, heat] randomness, chaos, disorder. [part of 2nd law of thermodynamics]
Second law of thermodynamics
When energy is transferred, there will be less energy available at the end of the transfer process than at the beginning. Due to entropy.
Potential energy
Energy stored in the position or arrangement of objects in a system.
Endergonic
“Energy in” positive change of G, NOT spontaneous.
What type of reaction would an endergonic reaction be?
Dehydration/condensation [anabolic]
Exergonic
“Energy out’ Negative change of G, spontaneous.
What type of reaction would an exergonic reaction be?
Hydrolysis [catabolic].
[]G=[]H-T[]S
Change of G equation
H
Enthalpy or total energy
G
Free energy
S
Entropy
T
Temperature
Activation energy
Minimum amount of energy required to start a reaction.
Do endergonic and exergonic reactions need activation energy?
Yes.
Cells store energy in chemical bonds by running ……..
Endergonic reactions that build compounds.
Cells run ……. That break the bonds
Exergonic reactions
Why does metabolism require enzymes?
Because it speeds up reactions. Reactions can occur without enzymes, but it could take decades.
Catalysis
The acceleration of a reaction rate by a molecule that is unchanged by participating in the reaction.
What are enzymes made out of?
Proteins [some are made of RNA].
Each enzyme has an …….
Active site.
Active site
Pocket in an enzyme where substrates react and are converted to products. An enzyme acts only on molecules that “fit” its active site.
Substrate
Molecule that an enzyme acts upon and converts to a product; reactant in an enzyme-catalyzed reaction.
Transition state
During a reaction, the moment at which substrate bonds are at the breaking point and the reaction will run spontaneously .
Enzymes help lower…….. required to bring on the…….
Activation energy, transition state.
Induced-fit
Substrate binding to an active site improves the fit between the two; This fit is necessary for catalysis.
What factors will influence an enzymes shape and function?
Temperature, pH, and salt concentration.
Metabolic pathway
Building, rearranging, or breaking down an organic molecule often occurs stepwise, in a series of enzymatic reactions.
Linear pathway
The reactions run straight from the reactant to the product.
Cyclic pathway
That last step regenerates a reactant of the first step.
Allosteric reaction
Enzymes have an Allosteric site, downstream products combine to this regulatory site causing the enzyme to change shape and prevent it from binding with substrates. This causes entire metabolic pathway to stop, and new products are no longer formed.
Feedback inhibition
Regulatory mechanism. Assembly line can speed up, slow down, or stop completely to prevent wasting resources and products. Achieved through Allosteric regulation.
Phosphorylation
Addition of a phosphate group to an organic molecule.
List coenzymes
ATP, NADH, FADH
Fluid mosaic
Model describes a membrane as a two dimensional liquid of mixed composition. Describes the organization of cell membranes. Phospholipids, steroids, proteins, and other molecules.
Do all cell membranes have transport proteins?
Yes.
Transport protein
Protein that helps SPECIFIC ions or molecules to cross a membrane.
Selective permeability
The ability of a cell membrane to control which substances and how much of them enter or leave a cell.
Diffusion
Spontaneous spreading of molecules or atoms through a fluid or gas. The spontaneous net movement high—>low concentration.
Isotonic
Describes two fluids with identical solute concentrations.
Tonicity
The capability of a solution to modify the volume of cells by altering their water content. Very important for homeostasis. All about solutes, this GOVERNS osmosis.
Osmosis
Diffusion of water across a selectively permeable membrane; occurs in response to a difference in solute concentration. Low concentration diffuses water to a higher concentration.
Osmotic pressure
The minimum pressure that must be applied to a solution to stop the flow of solvent molecules through a semipermeable membrane.
Endocytosis includes?
Pinocytosis, phagocytosis, receptor-mediated endocytosis
Pinocytosis
“Cell drinking”
Phagocytosis
“Cell eating”
What are two ways to make ATP
1) substrate level phosphorylation
2) oxidative phosphorylation
