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ACTIVE TRANSPORT ENDOCYTOSIS, AND EXOCYTOSIS
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3.5
Study Guide
KEY CONCEPT
VOCABULARY
Cells use energy to transport materials that cannot diffuse
across a membrane.
active transport
phagocytosis
endocytosis
exocytosis
MAIN !DEA: Proteins
can transport materials against a concentration gradient.
1. How is active transport different than simple diffilsion and facilitated difü¡sion?
Active transport is the movement of molecules against a concqntration gradient, whereas any type of
2.
How is active transport similar to facilitated diffusion?
Both involve the movement of molecules through selective membrane proteins.
3. List two characteristics that almost all transport proteins
Ail
rt
share.
the membrane and most cha
when
bind to a
m
or molecules.
4. List the key distinguishing feature of active transport proteins,
Active transport proteins use chemical energy to move a substance aqainst its concentration gradient
5.
Refer to Figure 3.25 to draw a picture in the box below to represent active transport
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inside
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6.
Most active transport proteins use energy from the breakdown
of
ATP
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Unit 2 Resource Book
McDougal Linell Biology
Study Guide
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STUDY GUIDE, CONTINUED
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MAIN IDEA: Endocytosis and exocytosis transport materials across the membrane
in vesicles.
7. A cell may transport a substance in
vesicles
if the substance is
too large to cross the membrane.
8.
During endocytosis, the vesicle membrane fuses with a lysosome, and the membrane
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c)
and its contents are broken down by
lysosomal enzymes
Complete the Y diagram below to compare and contrast the processes of endocytosis and
exocytosis. Under the heading "endocytosis," list the characteristics of endocytosis. Under
the heading "exocytosis," list the characteristics of exocytosis. At the bottom of the Y,
write the characteristics that both processes have in common. Then lightly cross out those
characteristics at the top of the Y.
Exocytosis
Endocytosis
uses energy, releases substances
uses energy, takes substances into a
cell, moves substances in vesicles
outside a cell, moves substances in
vesicles
B
oth
use energy, move substances in vesicles
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o
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Vocabulary Check
9.
r
What term means "cell eating" and describes a type of endocytosis?
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Phagocystosis
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1O. The prefix exo- means "out of," and the prefix endo- means "taking in." How do these
meanings relate to the meaning of exocytosis and endocytosis?
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Exocytosis is a process that releases substances outside a cell.
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o
Endocytosis is a process that takes substances into a cell
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11. What process drives molecules across a membrane against a concentration gradient?
Active transport.
18 Study Guìde
Unit 2 Resource Book
McDougal Littell Biology