Transcript Cellular Transport Notes (7.4)

7.4 – Cellular Transport
State Standards
SB1a
Explain the role of cell organelles for both
prokaryotic & eukaryotic cells, including the cell
membrane, in maintaining homeostasis & cell
reproduction.
SB1d
Explain the impact of water on life processes (i.e.
– osmosis/diffusion)
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Cellular Transport
 There are various mechanisms that transport
materials in and out of the cell. All of them
involve the plasma membrane and are at
the heart of homeostasis.
 There are 2 types of movement across the
plasma membrane:
 PASSIVE Transport
and
 ACTIVE Transport
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Passive Transport
 Movement of particles across the cell
membrane without using energy
 There are 3 types of passive transport:
 Diffusion
 Facilitated Diffusion
and
 Osmosis
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Passive Transport – Cont’d
Type 1: Diffusion
 Movement of substances across the cell
membrane from and area of high concentration
to an area of low concentration.
HIGH
LOW
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Passive Transport
Diffusion Cont’d
 Having different concentrations in different
areas creates a concentration gradient, and
molecules will naturally move from high to low.
Students:
Draw arrows on
the diagram to
show which
direction the
particles will
move.
7.4 – Cellular Transport
Passive Transport – Cont’d
More Diffusion Pics
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Passive Transport
Diffusion – Cont’d
Dynamic Equilibrium
 The solute
concentration is equal
inside & outside the
cell
 Molecules continue to
move, but the overall
concentration remains
the same.
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Passive Transport - Cont’d
Type 2: Facilitated Diffusion
 Movement of materials across the plasma
membrane through a protein
 THIS DOES NOT REQUIRE ENERGY!
Chapter 7
Cellular Structure and Function
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Passive Transport Cont’d
Type 3: Osmosis
 Diffusion of water across a selectively
permeable membrane.
 Water will naturally
move from where it is
highly concentrated to
where it is less
concentrated.
 This does NOT require
energy!
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Passive Transport
Osmosis Cont’d
 Tonicity affects
the movement
of water
 Isotonic Solution – think “equal”
 Hypotonic Solution – low solute concentration
 Hypertonic Solution – high solute concentration
Chapter 7
Cellular Structure and Function
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Passive Transport
Osmosis Cont’d
In an Isotonic Environment…
 Water and dissolved substances diffuse into and
out of the cell at an equal rate.
Plant Cell
Blood Cell
11,397x
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Passive Transport
Osmosis Cont’d
MEMORIZATION TIP: “Hypo-Hippo”
In a Hypotonic Environment…
 Solute concentration is higher inside the cell.
 Water diffuses into the cell.
Plant Cell
Blood Cell
13,000x
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Passive Transport
Osmosis Cont’d
MEMORIZATION TIP: “Salt Sucks”
In a Hypertonic Environment…
 Solute concentration is higher outside the cell.
 Water diffuses out of the cell.
Plant Cell
Blood Cell
13,000x
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Active Transport
 A process that uses energy to move molecules
across the cell membrane.
 There are 3 types of active transport:
 Active Transport using carrier proteins.
 Endocytosis
 Exocytosis
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Active Transport
with Carrier Proteins
 Uses energy to pump molecules across the cell
membrane from a region of lower concentration
to a region of higher concentration. This
movement goes against the natural
concentration gradient.
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Active Transport Cont’d
The Na+/K+ ATPase Pump
 Moves three
sodium ions out
of the cell and two
potassium ions
into the cell
Use your prior knowledge:
What is ATPase??
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Active Transport Cont’d
Endocytosis
 Process by which the
cell uses energy to
surround large particles
and bring them into the
cell
Chapter 7
Cellular Structure and Function
7.4 Cellular Transport
Active Transport Cont’d
Exocytosis
 Secretion of a
large amount of
material out of
the plasma
membrane
Chapter 7
Cellular Structure and Function
7.4 Formative
Questions
Which type of cellular transport does not
require an input of energy?
A. active transport
B. endocytosis
C. exocytosis
D. facilitated diffusion
Chapter 7
Cellular Structure and Function
7.4 Formative
Questions
How does osmosis occur between the
two solutions separated by the selectively
permeable membrane?
Chapter 7
Cellular Structure and Function
7.4 Formative
Questions
A. Sugar moves to the left.
B. Sugar moves to the right.
C. Water moves to the left.
D. Water moves to the right.
Chapter 7
Cellular Structure and Function
7.4 Formative
Questions
Which diagram shows a cell in a hypotonic
solution?
A.
B.
C.
Chapter 7
Cellular Structure and Function
Chapter Assessment
Questions
_______ is the net movement of particles from
an area where there are many particles of the
substance to an area where there are fewer
particles of the substance.
A. Diffusion
B. Endocytosis
C. Exocytosis
D. Equilibrium
Chapter 7
Cellular Structure and Function
Standardized Test
Practice
Why are the carrier proteins that move
substances across a plasma membrane
from a region of higher concentration to
a region of lower concentration called
pumps?
Chapter 7
Cellular Structure and Function
Standardized Test
Practice
A. They require energy to move substances
against a concentration gradient.
B. They open and close to allow substances
to diffuse across the plasma membrane.
C. They help with the osmosis of water
through the plasma membrane.
D. They pump water into the cell, causing
the pressure within the cell to increase.