Download 3.3 Cell Membrane TEKS 3E, 4B, 9A

3.3
Cell Membrane
The student is expected to:
3E evaluate models
according to their limitations in
representing biological objects or
events;
4B investigate and explain
cellular processes, including
homeostasis, energy conversions,
transport of molecules, and
synthesis of new molecules;
TEKS 3E, 4B, 9A
3.3
Cell Membrane
TEKS 3E, 4B, 9A
(Continued)
9A
compare the structures and functions of
different types of biomolecules,
including carbohydrates, lipids, proteins,
and nucleic acids
3.3
Cell Membrane
TEKS 3E, 4B, 9A
KEY CONCEPT The cell membrane is a barrier that
separates a cell from the external environment.
3.3
Cell Membrane
TEKS 3E, 4B, 9A
Cell membranes are composed of two phospholipid
layers.
3.3
Cell Membrane
TEKS 3E, 4B, 9A
Cell membranes are composed of two phospholipid
layers.
• The cell membrane has two major functions.
cell membrane
3.3
Cell Membrane
TEKS 3E, 4B, 9A
Cell membranes are composed of two phospholipid
layers.
• The cell membrane has two major functions.
– forms a boundary between inside and outside of the
cell
cell membrane
inside cell
outside cell
3.3
Cell Membrane
TEKS 3E, 4B, 9A
Cell membranes are composed of two phospholipid
layers.
• The cell membrane has two major functions.
– forms a boundary between inside and outside of the
cell
– controls passage of materials
cell membrane
inside cell
outside cell
3.3
Cell Membrane
TEKS 3E, 4B, 9A
Cell membranes are composed of two phospholipid
layers.
3.3
Cell Membrane
TEKS 3E, 4B, 9A
Cell membranes are composed of two phospholipid
layers.
• The cell membrane is made of a phospholipid bilayer.
cell membrane
3.3
Cell Membrane
TEKS 3E, 4B, 9A
Cell membranes are composed of two phospholipid
layers.
• The cell membrane is made of a phospholipid bilayer.
• There are other molecules embedded in the membrane.
cell membrane
carbohydrate
chain
cholesterol
protein
protein channel
protein
3.3
Cell Membrane
TEKS 3E, 4B, 9A
Cell membranes are composed of two phospholipid
layers.
• The cell membrane is made of a phospholipid bilayer.
• There are other molecules embedded in the membrane.
• The fluid mosaic model describes the membrane.
cell membrane
carbohydrate
chain
cholesterol
protein
protein channel
protein
3.3
Cell Membrane
TEKS 3E, 4B, 9A
Cell membranes are composed of two phospholipid
layers.
3.3
Cell Membrane
TEKS 3E, 4B, 9A
Cell membranes are composed of two phospholipid
layers.
• The cell membrane is selectively permeable.
Some molecules can cross the membrane
while others cannot.
3.3
Cell Membrane
TEKS 3E, 4B, 9A
Cell membranes are composed of two phospholipid
layers.
• The cell membrane is selectively permeable.
Some molecules can cross the membrane
while others cannot.
3.3
Cell Membrane
TEKS 3E, 4B, 9A
Chemical signals are transmitted across the cell
membrane.
• Receptors bind with ligands and change shape.
• There are two types of receptors.
3.3
Cell Membrane
TEKS 3E, 4B, 9A
Chemical signals are transmitted across the cell
membrane.
• Receptors bind with ligands and change shape.
• There are two types of receptors.
– intracellular receptor
3.3
Cell Membrane
TEKS 3E, 4B, 9A
Chemical signals are transmitted across the cell
membrane.
• Receptors bind with ligands and change shape.
• There are two types of receptors.
– intracellular receptor
– membrane receptor
3.3
Cell Membrane
The student is expected to:
4B investigate and explain
cellular processes, including
homeostasis, energy conversions,
transport of molecules, and
synthesis of new molecules
and
9A compare the structures and
functions of different types of
biomolecules, including
carbohydrates, lipids, proteins,
and nucleic acids
TEKS 3E, 4B, 9A
3.3
Cell Membrane
TEKS 3E, 4B, 9A
KEY CONCEPT Cells use energy to transport materials
that cannot diffuse across a membrane.
3.3
Cell Membrane
TEKS 3E, 4B, 9A
The cell theory grew out of the work of many
scientists and improvements in the microscope.
• Passive transport requires no
energy from the cell.
• Active transport is powered
by chemical energy (ATP).
• Active transport occurs
through transport protein
pumps.
• Cells use active transport to
maintain homeostasis.
3.3
Cell Membrane
TEKS 3E, 4B, 9A
A cell can import and export large materials or large
amounts of material in vesicles during the
processes of endocytosis and exocytosis.
• Cells use energy to transport material in vesicles.
• Endocytosis is the process of
taking material into the cell.
• Phagocytosis is a type of
endocytosis.
3.3
Cell Membrane
TEKS 3E, 4B, 9A
A cell can import and export large materials or large
amounts of material in vesicles during the
processes of endocytosis and exocytosis.
• Cells use energy to transport material in vesicles.
• Exocytosis is the process of
expelling material from the
cell.
3.3
Cell Membrane
The student is expected to:
4B investigate and explain
cellular processes, including
homeostasis, energy conversions,
transport of molecules, and
synthesis of new molecules
and
9A compare the structures and
functions of different types of
biomolecules, including
carbohydrates, lipids, proteins,
and nucleic acids
TEKS 3E, 4B, 9A
3.3
Cell Membrane
TEKS 3E, 4B, 9A
KEY CONCEPT Cells use energy to transport materials
that cannot diffuse across a membrane.
3.3
Cell Membrane
TEKS 3E, 4B, 9A
The cell theory grew out of the work of many
scientists and improvements in the microscope.
• Passive transport requires no
energy from the cell.
• Active transport is powered
by chemical energy (ATP).
• Active transport occurs
through transport protein
pumps.
• Cells use active transport to
maintain homeostasis.
3.3
Cell Membrane
TEKS 3E, 4B, 9A
A cell can import and export large materials or large
amounts of material in vesicles during the
processes of endocytosis and exocytosis.
• Cells use energy to transport material in vesicles.
• Endocytosis is the process of
taking material into the cell.
• Phagocytosis is a type of
endocytosis.
3.3
Cell Membrane
TEKS 3E, 4B, 9A
A cell can import and export large materials or large
amounts of material in vesicles during the
processes of endocytosis and exocytosis.
• Cells use energy to transport material in vesicles.
• Exocytosis is the process of
expelling material from the
cell.