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UNIT 4 CELL BOUNDARIES AND TRANSPORT
Unit 4 test: October 16, 2018
CELL BOUNDARIES
Cell Wall–_____________ & _____________ the cell
– Lies outside of the __________________
– Is made of ______________& ______________
–Plant cell walls are mainly ___________
– Fungi cell walls are mainly ___________
support protect
cell membranecarbohydrates
proteins
cellulose
chitin
• II. CELL Membrane
• A cell is defined as the smallest _________ unit of life. In order to maintain ___________, _______ must be moved into the cell and ______ must be transported out of the cell. In addition, some cells produce _________ and other materials designated for export. All materials moving in and out of the cell must pass through the____________a ______________boundary found in ____ cells.
CELL BOUNDARIES
workinghomeostasis nutrients
wastes
hormones
cell membrane semi permeableall
Cell Membrane in a Nutshell (187-190)
– Made mainly of ____________ & _________
– Hydrophobic tails of phospholipids make molecules line up as a
_______ with polar head facing
_____ and nonpolar
tails facing ___.
phospholipid proteins
bilayerout
in
Function
– Membranes are __________________ = Semi-permeable, picky
– Allow certain molecules to pass through; but keeps others out
– __________ what enters & leaves the cell
– Helps maintain ___________
selectively permeable
Controls
homeostasis
Other components of the cell membrane
– Proteins-• Peripheral- on the inside or outside surface. Can be
partially embedded into the cell membrane or can be found attached to an integral membrane protein.–On the outside surface, ____________ to inside
cell; “receptor protein”–On the inside surface, __________ the call
membrane to the cell’s internal support structure (cytoskeleton) giving cell its shape. “Anchor proteins”
• Transport proteins (also called integral)-_______________________ through the membrane; used as channels or tunnels to move things in or out of the cell
transmit signals
anchors
embedded all the way
Other components of the cell membrane
•Cholesterol- only in _______ cells
–Helps prevent fatty acid tails from ________ together
–Provides ________ for ________
cell (no cell wall)
animal
sticking
stability animal
Other components of the cell membrane
• Carbohydrates- in chain form; on outside surface
–Used to ____________ ; cell ID tags
–If found on top of a protein the whole structure is called a _____________
–If found on top of a phospholipid the whole structure is called a _________
recognize self
glycoprotein
glycolipid
Label the following cell membrane
1. Transport/Integral Protein2. Peripheral Protein on the inside 3. Glycoprotein4. Glycolipid5. Cholesterol
CARBOHYDRATES
• On the outside of the cell membrane to identify as “self or non-self”
PROTEINS
• Embedded in the bilayer
• Serve as channels & pumps for transport of specific molecules across the cell membrane
What biomolecule regulates what can enter or leave the cell w/o a channel or
pump?
A. Lipid
B. Carbohydrate
C. Protein
D. Nucleic Acid
What biomolecule Serve as channels & pumps for transport
A. Lipid
B. Carbohydrate
C. Protein
D. Nucleic Acid
What biomolecule is used to toidentify as “self or non-self”
A. Lipid
B. Carbohydrate
C. Protein
D. Nucleic Acid
Non-polar, middle portion of cell membrane
A. a
B. b
C. c
D. d
E. e
Embedded in cell membrane, serve as channels & pumps
A. a
B. b
C. c
D. d
E. e
Polar portion of cell membrane oriented towards water
A. a
B. b
C. c
D. d
E. e
Provides stability for animal cell membrane
A. a
B. b
C. c
D. d
E. e
Serve as “id” tags for cell
A. a
B. b
C. c
D. d
E. e
CELL TRANSPORT
Passive Transport• Does NOT require ________
• Movement of substances from a ______concentration to ______
• 3 Types:o Diffusion
o Facilitated diffusion
o Osmosis
energy
highlow
DIFFUSION
Diffusion:
• Random movement of molecules in a ________or _____
Many substances move across
the ________________ by
diffusion, for example
_________________________
• Example: odor gradually
fills a room
cell membrane
water, oxygen, & small molecules
liquidgas
FACILITATED DIFFUSION
Facilitated Diffusion:
• Diffusion of _____________through a _____________
• Ex: glucose as it is transported across a cell membrane by a protein channel
large molecules
protein channel
FACILITATED DIFFUSION
• Protein channels provide larger openings for larger molecules like ________________. In addition, due to the _________ fatty acid tails that make up most of the phospholipid bilayer, _____ molecules and _____ utilize protein channels.
glucose, & fructose
non-polar
polar ions
FACILITATED DIFFUSION
• This includes ________, which utilizes specialized protein channels known as ________________.
***A protein pump is active transport so this sentence should be in the active transport section
Na & K
Protein pumps
OSMOSIS
Osmosis:
• Diffusion of ________from a _______ water concentration to a ________ water concentration through a __________________ membrane. There are comparative terms used to describe the water versus solute concentration on either side of the a membrane:
water highlow
Selectively permeable
OSMOSIS
• Hypertonic = __________________solute; _________________water
• Hypotonic = ____________________solute; _________________water
– Water always moves from ___________→ ______________
higher concentrationlower concentration
lower concentration
higher concentration
hypOtonic
hypertonic
OSMOSIS
• Isotonic = Relative concentrations of ______and ______ are ________
– There will be ___ net movement of water if two solutions are isotonic
water
solute equal
no
OSMOSIS
• Cells must have a mechanism for counteracting the pressure osmosis can create, otherwise a cell could swell & burst or explode when it is placed in a ___________ environment
• How to control Osmotic Pressure:o Cell wall - Rigid boundary found in ________________
o Physically prevents cell from expanding
o Contractile vacuole- Actively________ water out of cell single-celled organisms without ________
o Blood/Extracellular Fluid- is mostly water to equalize osmotic pressure. Designed to be __________ with cells.
hypotonic
pumpsCell walls
Plants, bacteria, fungi & some protists
isotonic
-Hypotonic; -cell will undergo cytolysis or lyse (the cell will burst)-This can kill the animal cell
-Hypertonic; -cell will crenate (the cell will shrivel up)-This causes cell to dehydrate and not function
-isotonic; -preferred cell state
-Hypertonic; -cell will undergo plasmolysis (cell membrane pulls away from cell wall)
-isotonic; -Cell does not mind being in this state; neither beneficial or harmful to the cell
-Hypotonic; -cells see increased turgor pressure-This is the preferred state for plant cells
ACTIVE TRANSPORT
Requires energy in the form of ATP
3 types:• Protein Pumps
• Endocytosis
• Exocytosis
PROTEIN PUMPS
Protein Pumps:
• 1. Protein Pumps –Energy-requiring process during which membrane proteins pump molecules across a membrane
____________________
from a ______concentration to a ________concentration.
concentration gradient
low
high
PROTEIN PUMPS
An example is the sodium-potassium pump. Its purpose is to establish an _____________gradient in cells by pumping __ sodium ions (__) out of the cell for every __ potassium ions (__) pumped into the cell. This slight ________charge inside the cell relative to the outside is very important for ________________
and _________________.
electrochemical
3 Na
2 Knegative
muscle contractions
Nerve impulses
ENDOCYTOSIS AND EXOCYTOSIS
Endocytosis: “cell eating or sucking”.
Larger substances are moved into the cell from the
exterior by extending the cell membrane, forming a
vesicle around the substance. Examples include
macrophages, amoeba, etc.
Exocytosis- “cell spitting ”. Export of molecules from the inside of the cell to the exterior of the cell by a vesicle fusing with the cell membrane. Mechanism used to release hormones from cells
ENDOCYTOSIS AND EXOCYTOSIS
ENDOCYTOSIS
Endocytosis
Exocytosis
Random movement of molecules in a liquid or gas
A. Active transport
B. Diffusion
C. Endocytosis
D. Exocytosis
E. Facilitated Diffusion
F. Osmosis
G. Passive Transport
H. Protein Pump
Requires energy in the form of ATP
A. Active transport
B. Diffusion
C. Endocytosis
D. Exocytosis
E. Facilitated Diffusion
F. Osmosis
G. Passive Transport
H. Protein Pump
cell sucking in or eating
A. Active transport
B. Diffusion
C. Endocytosis
D. Exocytosis
E. Facilitated Diffusion
F. Osmosis
G. Passive Transport
H. Protein Pump
Diffusion of specific molecules through a protein channel
A. Active transport
B. Diffusion
C. Endocytosis
D. Exocytosis
E. Facilitated Diffusion
F. Osmosis
G. Passive Transport
H. Protein Pump
Diffusion of water through a selectively permeable membrane
A. Active transport
B. Diffusion
C. Endocytosis
D. Exocytosis
E. Facilitated Diffusion
F. Osmosis
G. Passive Transport
H. Protein Pump
Movement of molecules from high concentration to low, does NOT
require energyA. Active transport
B. Diffusion
C. Endocytosis
D. Exocytosis
E. Facilitated Diffusion
F. Osmosis
G. Passive Transport
H. Protein Pump
Movement of ions and molecules against the concentration gradient,
requires energyA. Active transport
B. Diffusion
C. Endocytosis
D. Exocytosis
E. Facilitated Diffusion
F. Osmosis
G. Passive Transport
H. Protein Pump
Cell spitting out or pooping
A. Active transport
B. Diffusion
C. Endocytosis
D. Exocytosis
E. Facilitated Diffusion
F. Osmosis
G. Passive Transport
H. Protein Pump
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