Download Enzymes and Cell Transport study guide

Enzymes, Chemical Reactions and Cell Transport Mechanisms Test Study Guide
Enzymes –


Shape determines function
o Specifically shaped for one substrate (Lock-key)
o Denatured with pH, Temp and Salinity – when an enzyme is denatured – the shape changes.
o If shape changes, function is reduced – cannot bind substrate anymore if shape is changed
Catalyst
o Speeds up reaction rate
o Reduces activation energy
o Remains unchanged from reaction
Chemical Reactions –


Endothermic: absorbs energy
o Makes bonds
o Dehydration synthesis
Exothermic: releases energy
o Breaks bonds
o hydrolysis
Controlled via the Cell Membrane
Passive Transport
Active Transport
Does NOT require energy, moves from HIGH
concentrations to LOW concentrations
DOES require energy, moves from LOW
concentrations to HIGH concentrations
Diffusion
Moves small molecules,
like CO2 & O2 gases,
directly through the
membrane
Osmosis
Movement of water
across the membrane
3 Types
of
Solutions
Hypertonic
Water moves out of the
cell & it shrinks
Isotonic
Water moves
equally in and
out of the cell;
it stays the
same size
Facilitated
Diffusion
Uses transport proteins
to move large molecules
through the membrane
WITHOUT energy
Hypotonic
Water moves into the
cell & it swells
Protein
Pumps
Transport proteins that
require energy to do
work. Example: Sodium /
Potassium Pumps are
important in nerve
responses.
(3 Na+ are moved out
and 2 K+ are moved in)
Endocytosis
Materials ENTER the cell
through a vesicle formed
by the membrane
Exocytosis
Materials EXIT the cell
through a vesicle formed
by the Golgi Body