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

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 outside cell inside 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 outside cell inside 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 membrane Cell membranes are composed of two phospholipid layers. The cell membrane is made of a phospholipid bilayer.

3.3 Cell Membrane TEKS 3E, 4B, 9A cell membrane 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. protein cholesterol protein carbohydrate chain protein channel

3.3 Cell Membrane TEKS 3E, 4B, 9A cell membrane 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. protein cholesterol protein carbohydrate chain protein channel

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