Chapter 4 Pt.2- Enzymes Flashcards
Enzymes
Proteins that act as biological catalysts within living organisms
Characteristics of Enzymes
Very efficient-effective in low numbers and concentration
Work only on one substance (substrate) for one reaction
Not used up entirely
How enzymes work
Speed up chemical reactions by lowering activation energy
Enzymes bind with substrates at the active site in a “lock and key” manner
Have optimal conditions for their functions
Denaturization can occur
How does the cell control the rate of reaction?
By limiting the activity of enzymes
-Inhibition (competitive and non-competitive)
Non Competitive Inhibition
An inhibitor changes the shape of the active site so the substrate and enzyme cannot bind
Competitive Inhibition
An inhibitor blocks the active site and the substrate from connecting
Passive Transport
Does not require energy
Simple Diffusion
Small molecules move from an area of high concentration to one of low concentration
(Food coloring in water)
Facilitated Diffusion
A membrane protein carries a molecule across the membrane from high to low concentration
Osmosis
The movement of water across a semi-permeable membrane
Isotonic Solution
Solution with the same concentration of solute on each side of the membrane
Hypotonic
Low amount of solute in a solution relative to inside of the cell
Water moves from outside to inside
Cells without cell walls will burst
Cells with cell walls will get firm but not burst
Hypertonic
High solute solution relative to inside the cell
Water moves inside out
Cell membrane will shrink
Active transport
Requires energy
Membrane transport proteins carry molecules from low to high concentrations
