Chp5 The Working Cell Flashcards
Difference between kinetic and potential energy.
Kinetic - energy in motion, potential- energy that is waiting to be released
Catabolic pathways
the degradation (or breakdown) of complex molecules into simpler ones
Anabolicpathways
require energy to synthesize larger molecules
Laws of thermodynamics: 1st and 2nd law
1st. Energy is conserved, it’s form can be converted
2nd. Energies can flow
what is a Exergonic Reaction
the free energy of the reactants is higher than the free energy of the products . Energy is released to the environment, which overcomes the activation energy of the reaction and makes it spontaneous.
Endergonic Reaction.
the free energy of the products is higher than the free energy of the reactants ((∆G > 0; energy is stored in the products), so the reaction is not spontaneous and additional energy must be supplied to make the reaction proceed
ATP (adenosine triphosphate)
consists of an organic molecule called adenosine plus a tail of three phosphate groups and is broken down to ADP
How does ATP power cellular work?
acts like an energy shuttle, stores energy obtained from food, and releases it later as needed Transfers energy from the reaction that releases energy to the one that needs energy
What is activation energy?
Energy required to activate reactants and trigger a chemical reaction.
Factors affecting enzyme activity
if an inhibitor is present.
Inhibitors
disrupts enzymes funcitons
Coenzymes
Coenzymesandcofactorsare molecules that help an enzyme or protein to function appropriately.Coenzymesare organic molecules and quite often bind loosely to the active site of an enzyme and aid in substrate recruitment
cofactors
do not bind the enzyme
What is the function of plasma membranes
Membranes regulate the flow of materials into and out of the cells
Structure of membrane (3)
phospholipids, Integral & Peripheral proteins
List the various functions membrane proteins carry out.
Transport in and out of the cell
Enzymes
Cell Signaling
Cell-cell recognition
Active transport
Active transport requires that a cell expend energy to move molecules across a membrane.
Passive transport
diffusion of a substance across a membrane without the input of energy
If someone at the other end of a restaurant smokes a cigarette, you may breathe in some smoke. The movement of smoke is similar to what type of transport?
diffusion
Osmosis
diffusion of water across a selectively permeable membrane
Facilitated Diffusion
polar substances that do not cross membranes can be transported across the membrane with the help of proteins.
The total solute concentration in a red blood cell is about 2%. Sucrose cannot pass through a red blood cell’s plasma membrane, but water and urea can. Osmosis will cause such a cell to shrink the most when the cell is immersed in which of the following?
a hypertonic sucrose solution
Enzymes
catalyze specific reactions.
If you immerse a living cell in a hypotonic solution, water will tend to ____________
diffuse into the cell
