LEQ: How do vesicles allow cells to move chemicals in bulk?

1

• LEQ How do vesicles allow cells to move
  chemicals in bulk?
• Reading 3.2 (cytoskeleton, membrane-bound
  organelles)
• 3 most important things to remember about
  transport across membranes list discuss
• Key terms bulk transport, vesicle

2

• Which best describes passive transport?
• A) requires transport proteins
• B) requires no energy from the cell
• C) requires an isotonic solution
• D) requires enzymes
• What is the term for the diffusion of water
  across a permeable membrane?
• A) osmosis
• B) equilibrium
• C) transport
• D) isotonic

3

• The difference in the concentration of dissolved
  solutes from one location to another is called
• A) concentration gradient
• B) concentrated solution
• C) saline solution
• D) dynamic gradient
• Which process uses proteins to move molecules
  against a concentration gradient?
• A) active transport
• B) passive transport
• C) simple diffusion
• D) osmosis

4
3.5 Active Transport, Endocytosis, and Exocytosis
Bulk transport requires the use of small membrane
bound structures to move chemicals.

• Purpose
• Move chemicals in bulk
• Requires energy
• 1) Endocytosis brings chemicals into the cell
• Phagocytosis (eating solids) consume other
  cells!

5

• Chemical signals are transmitted across the cell
  membrane.
• Signal (ligand) binds to a protein receptor
• Membrane receptors hydrophilic signals (left)
• Intracellular receptors hydrophobic signals
  (right)

6
3.5 Active Transport, Endocytosis, and Exocytosis

• 2) Exocytosis releases chemicals from the cell
• Release waste products
• Signal release
• Neurotransmitters
• Hormones
• Immune system molecules

7
3.5 Active Transport, Endocytosis, and Exocytosis
8
(No Transcript)
9

• Summary
• Speculate why is bulk transport essential for a
  cell to maintain homeostasis?
• How is the structure of a vesicle/membrane
  related to the function of bulk transport and
  need for active transport mechanisms?