Download Use prefixes, suffixes, and roots to define the

Cell Membrane Transport
GPS Standards
SAP1. Students will analyze anatomical
structures in relationship to their
physiological functions.
d. Relate cellular metabolism and transport to
homeostasis and cellular reproduction.
Learning Goals
By the end of this section, you will be able
to:
 Describe the components of the cell
membrane and their functions.
 Relate cellular transport to homeostasis.
 Differentiate between passive transport
processes and active transport processes.
Medical Terminology
Use prefixes, suffixes, and roots
sheet to define the following:
Use prefixes, suffixes, and
roots to define the following:
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biendoexoextrahydrointerintraphagopinotrans-osis
-philic
-phobic
cyt
integral
peripheral
prefix
suffix
transport
bilayer
extracellular
endocytosis
exocytosis
hydrophilic
hydrophobic
integral protein
intracellular
peripheral protein
phagocytosis
pinocytosis
root
The Cell Membrane
The cell membrane is a selectively
permeable membrane that determines
which molecules can come into the cell
and which molecules can leave the cell.
Cell Membrane
Nucleus
Transverse Section
of the cell
membrane
The Cell Membrane
Cell Membrane Components
1. Phospholipid bilayer
– Made up of
• Hydrophilic head
• Hydrophobic tail
– Allows small molecules, like water and gases,
to pass through the membrane easily
Cell Membrane Components
Continued
2. Proteins
– Integral proteins
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Permanently imbedded in the membrane
Used as carrier proteins for large molecules
– Peripheral proteins
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Loosely bonded to the internal and external
surfaces of the membrane
Mainly used in cell to cell communication and the
immune response
Passive Transport
• A process that moves molecules across
the cell membrane without energy from the
cell
• Moves molecules from high to low
concentrations
• Like riding a bike downhill
• Processes
– Diffusion
– Osmosis
– Facilitated Diffusion
Diffusion
The movement of molecules from an
area of higher concentration to an
area of lower concentration.
Diffusion
Osmosis
• The diffusion of water across a
selectively permeable membrane.
• Osmotic solutions can be
– Hypotonic (hypo- means “less than”)
– Isotonic (iso- means “the same”)
– Hypertonic (hyper- means “more than”)
Osmosis
Hypertonic
Isotonic
Hypotonic
Cells in Osmotic Solutions
Facilitated Diffusion
The diffusion of molecules across a
membrane with the help of transport
molecules imbedded in the cell
membrane.
Facilitated Diffusion
Facilitated Diffusion
Active Transport
• A process that drives large molecules
across the cell membrane from a region of
lower concentration to a region of higher
concentration
• Like riding a bike uphill
• Processes
– Endocytosis
– Exocytosis
– Ion Pumps
Endocytosis
• Molecules are brought into the cell by
vesicles formed from the cell
membrane
• Processes
– Pinocytosis. The cell takes tiny droplets
from its surroundings into tiny vesicles.
– Phagocytosis. The vesicle engulfs food
particles that are digested by
lysosomes.
Endocytosis
Exocytosis
• Molecules are forced out of the cell by
vesicles made by the Golgi apparatus
Exocytosis
Exocytosis
Ion Pumps
Ion pumps use integral proteins and energy (ATP) to
transport ions, such as sodium (Na) and potassium (K)
across the membrane.