Transcript PASSIVE TRANSPORT

Warm up 10/15
• Draw a plasma membrane & Include the following
• Label correct parts of the phospholipids hydrophobic and
hydrophilic.
• Integral proteins
• Peripheral proteins
• Cholesterol
• What does semi-permeable mean?
PASSIVE TRANSPORT
Chapter 4- 5: Notebook #9
(Ws #1: Notebook #8)
Textbook pg. 97-102
Solutions
2
Parts:
Concentration: A measure of how much
solute per unit of solvent
ex/ 200mg NaCl / mL H20
Solution =
Solute (that which is
dissolved)
+
Solvent (the liquid that does
the dissolving)
These glasses containing red dye demonstrate
qualitative changes in concentration. The
solutions on the left are more dilute, compared
to the more concentrated solutions on the right.
Passive transport
• Movement across the cell membrane without
energy.
• What characteristic does the cell membrane
have?
Diffusion
• Movement of molecules from area of high concentration
(CONC) to area of low concentration
Concentration Gradient
• Molecules have kinetic
energy
• Concentration
Gradient: difference
between high and low
concentration
• Molecules move “down”
gradient.
• Molecules move until
they reach equilibrium
(when all molecules are
evenly spread out).
Warm up 10/17
Observing Osmosis
Mini-Lab
• Sketch and Label a
typical Bacteria Cell
• Be sure to include:
• Cell Membrane
• Capsule
• Cytoplasm
• Make prediction
• Dump-Liquid in Sink
• Weigh Grape in paper cup
• Trash plastic cup and grape
• Chromosomes
• Finish Lab
• Flagella
• Due Tomorrow!
• Pilus
Osmosis
• Osmosis: special diffusion of water across membrane
• A solution is made of a solute dissolved in a solvent (like
water).
• Direction of movement is dependent on solutes outside
cell.
Hypotonic
• Concentration of
solutes is lower
outside the cell and
water moves into the
cell  cell swells
Hypertonic
• Concentration of
solutes is higher
outside the cell and
water moves out the
cell  cell shrinks
Isotonic:
• Concentration of
solutes inside =
outside  so no water
moves
Observing Osmosis
Mini-Lab
Warm up
• Sketch and Label and
typical Bacteria Cell
• Make prediction
• Be sure to include:
• Weigh Grape
• Cell Membrane
• Finish Lab
• Capsule
• Due Tomorrow!
• Cytoplasm
• Chromosomes
• Flagella
• Pilus
Facilitated Diffusion
• Molecules too big to move across the membrane use
carrier proteins Ex. Glucose
Warm Up 10/18
• Define the following in 10words or less. Use the terms
Solute and Solvent and Solution
• Hypertonic
• Hypotonic
• Isotonic
• Turn in Warm-ups (Oct 9 – 18) and Lab
• You have 5 min.
Facilitated Diffusion
Particles may be too big to pass through.
ex. Glucose
Diffusion of
particles unable
to pass through
the membrane on
their own.
Carrier Protein: Proteins
found in the cell membrane
that “carry” the particles
through.
Particles may be polar (charged) and unable
to pass through the non-polar layer of the
membrane.
ex. Aspartic Acid
Facilitated Diffusion still transports particles
from high concentrations to low
concentrations.
Facilitated Diffusion Continued
Sensitivity: Just like enzymes, carrier
proteins are sensitive to changes in pH
and temperature
(homeostasis is important for transport
rates/ability)
2-way travel: The diffusion can occur
into or out of the cell based on where
the high/low concentrations are found.
Specificity: Just like enzymes, carrier
proteins are specific to one type of
substance they can transport.
(substrate fits the protein like a key in a
lock)
Diffusion through Ion Channels
Diffusion of ions
(charged atoms)
through the
membrane
Ion Channel: carrier proteins that specialize
in transporting a specific ion across the
membrane.
ex. Na+, K+, ClSome
Ion
Channel
s are
always
open
As charged particles, ions
are unable to pass through
the membrane on their
own.
Some channels work as gates, only opening under
certain conditions.
3 Ways that open gates: stretching the membrane,
electrical stimuli, chemicals in the cytosol or outside
Warm up 10/22
• What are the 4 types of passive transport.
• What are the roles of carrier proteins?
• Are carrier proteins and ion channels peripheral or
integral proteins? Explain why is 15 words or less.
(If you are not appropriately far along when Mr.
E comes around you will not get a stamp.)
ACTIVE TRANSPORT
pp. 103-106
Active Transport
•Requires energy
• Molecules move from an area of
low concentration to an area of
high concentration
• Move against the concentration
gradient
• Carrier proteins that are active are called pumps.
• Protein binds to a specific molecule.
• Protein transfers the molecule to the other side.
• Sodium-Potassium Pump: transports Na+ and K+
against (not down) gradient
3 Na+ out and 2 K+ in
• Requires Energy in the Form of ATP  ADP
Membrane pumps
Endocytosis and Exocytosis: used to
move very large molecules in and out of
the cell
Endocytosis: ingest large molecules into
cell
• Material is engulfed by cell membrane.
• Membrane makes a pouch.
• Pouch then pinches off and makes a vesicle.
• Vesicle binds with lysosome.
Phagocytosis: a form of endocytosis in
which immune cells attack and ingest
bacteria
Exocytosis: (the reverse of endocytosis)
moving large particles out of the cell
CELL DIVERSITY AND
CELL SIZE
Chapter 5
pg. 72-73
Cell shape
• Cell shape related to function of the cell
• Only write what is in black! (Notes can be written in
Specialized Cells WS from 10/16/12)
Red Blood Cells
• Found in your circulatory system.
• Your red blood cells do several important jobs. They carry
oxygen from the lungs to all the cells in the body and
carbon dioxide back to the lungs. They carry food from the
stomach to all the cells in the body.
• Red blood cells do not have a nucleus and have very few
organelles. This is so that they can carry
the gasses that they need to carry.
There are chemicals that attach to the
nutrients or gas to carry it. The cells are
round and are indented in the middle
to increase their surface area.
Skin Cells
• The skin layer is about 10 cells deep. Your skin is
constantly wearing out and being replaced. When a skin
cell dies, it falls off and becomes dust. You lose 30,000 to
40,000 dead skin cell every minute! Adults have about 20
square feet of skin.
• There are chemicals inside the cells called melanin and
carotene that make your skin the unique color it is.
• Skin cells are long and flat. They have the organelles that
most animal cells would have.
Nerve Cells
• Nerve cells are the communication
system in your body.
• Your brain has 100 billion neurons (nerve cells in the
brain).
• Most cells divide and create new cells in your body.
Neurons never divide or are replaced. This makes your
neurons the longest living cells in your body.
• Nerve cells are very long and have arms coming out of
them that connect to other cells. One nerve cell can be up
to 1 meter.
Heart Cell
• Heart cells are a type of muscle cell that is found in your
heart.
• Your heart beats about 70 to 80 times per minute or
100,000 times a day. Your heart pumps 2.4
ounces (or 70 mL) per heart beat. This
equals 1,900 gallons (7,200 liters) a day!
• Heart cells are like other muscle cells and
are long and thin. They have a lot of
mitochondria because they work and
move all the time. They also have muscle
fibers called actin and myosin to
make your heart beat.
Warm up 10/23
• What are the two types of active transport?
• Where does the energy come from for the
Sodium-Potassium pump?
• Describe endocytosis!
Bone Cells
• You have 206 bones in your body. Your bones are made
of cells. Cells probably seem really soft and not very
strong. But bone cells make a chemical that hardens
around each cell. This makes your bones strong!
• Bone cells are shaped like cubes and columns. They
make proteins and control how many minerals (like
calcium) are around the cell.
• These cells have a lot of endoplasmic
reticulum and Golgi complex because
they need to make a
lot of protein.
Rods and Cones
• When you see light enters your eyes and is
focused on the back of your eyes (the retina).
There are 2 kinds of cells that make up the
retina: rods and cones.
• Rods help you see the size, shape and
brightness of an object, but don’t help you see
color. They can see in very dim light and for
peripheral vision (when you are not looking
directly at something). Cones help to see
detail and the color of an object. You have 130
million rods in each eye (compared to 7
million cones).
•
Leaf Cell
• Leaves have several kinds of cells. The top layer is called
the epidermis. The layer just underneath is called the
palisade layer. This is where photosynthesis happens.
Other cells in the leaf protect it, get carbon dioxide and
give off oxygen.
• Palisade cells are long and flat to absorb the most
sunshine. They are packed with chloroplasts to do
photosynthesis. There are up to 50 chloroplasts in one
cell! These cells are packed tightly together.
Cell size
• Surface area to volume ratio decreases with increasing
cell size (EX. 6:1 vs 3:1)
• Volume increases quicker than the surface area
Summary of the Mini-Lab
• What was different about the 3 cubes?
• What happened when we placed the cubes (model cells)
in the solution of NaOH?
• Did the NaOH diffuse the same distance?
• Why is this important to the cell?
• Substances cannot get to the center, or out of the
center of the cell if it’s too big
What does this mean
for the cell?
• The bigger the volume the less surface area
• not enough surface area to meet the needs of the
increasing volume
• distance to center increases as cell increases
• Difficulty exchanging materials (such as nutrients,
oxygen, and waste products) across the cell
ACTIVE TRANSPORT
Chapter 5
pg. 103-106
Active Transport
• Requires energy
• Molecules move from an area of low
concentration to an area of high concentration
• Move against the concentration gradient
Membrane pumps
• Carrier proteins that are active are called pumps.
• Protein binds to a specific molecule.
• Protein transfers the molecule to the other side.
• Sodium-Potassium Pump: transports Na+ and
K+ against (not down) gradient
• 3 Na+ out and 2 K+ in
Endocytosis and Exocytosis
• Used to move very large molecules in and out of the cell
Endocytosis
• Ingest large molecules into cell
• Material is engulfed by cell membrane.
• Membrane makes a pouch.
• Pouch then pinches off and makes a vesicle.
• Vesicle binds with lysosome.
Phagocytosis
• A form of endocytosis in which immune cells attack and
ingest bacteria
Exocytosis
• (the reverse of endocytosis) moving large particles out
of the cell