Chapter 5 Flashcards
Membranes are composed of..
bilayer phospholipids w/ proteins and fliud mosiac
Diffusion
tendency of particles to spreads out evenly in available space
Passive
movement of enzyme without using NRG
Osmosis
diffusion of water across membrane
Tonicity
ability of a sol’n to cause a cell to gain or lose water
Isotonic
concentration of solute is same on both sides of membrane
Hypotonic
solute concentration is lower outside cell, water moves into cell and will expand, may burst
Hypertonic
solute concentration is higher outside of the cell, water move out of cell and cell will shrink
Osmoregulation
control of water balance
Active transport
cell must expend NRG to move a solute against its concentration
Facilitated diffusion
move across membranes with help of specific transport proteins. doesn’t require NRG
Exocystosis
export bulky molecules
Endocystosis
import substances useful to livelihood of the cell
Energy
capacity to cause change or to perform
Kinetic NRG
NRG of motion
Potential NRG
NRG that matter possesses as a result of it’s location/structure
Thermodynamic
study of NRG conversions that occur in a collection of matter
2 laws that govern NRG conversions
1: NRG is constant (never created or destroyed
2: NRH conversions increase disorder of universe
Metabolism
organisms total chemical reaction
ATP
Adenosine triphosphate. powers nearly all forms of cellular work
3 main types of cellular work
- Chemical 2.Mechanica 3. Transport
Enzymes
speed up the cells them reaction by lowering NRG barriers
Activation NRG
NRG barrier must be overcome before chemical reaction can begin
Substrate
specific reactant that an enzyme acts on
Active site
substrate fits into a region of the enzyme
Cofactors are..
inorganic
Coenzymes are…
organic
Cells must control enzyme activity by..
- switch off genes encoding specific enzymes
- regulate activity go enzymes once made
Inhibitor
chemical that interferes with and enzyme activity
Competitive inhibitors
block substrates from entering the active site and educes an enzymes productivity
Noncompetitive inhibitors
bind to enzyme somewhere other than the active site, prevent the substrate from binding
feedback inhabitation
product may act an inhibitor of one of the enzymes in the pathway that produced it
