Transcript Structure and Function of the Cell

Chapter 7.1 and 7.2
Cytoplasmic streaming video
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http://www.youtube.com/watch?v=8edk6nGMwMs
Cell Assignment
Examples:
 Raquel & Tiffany’s Assignment
 http://www.youtube.com/watch?v=R4c11l4Bjqo
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Edible plant cell:
http://www.youtube.com/watch?v=dtoM5T3UUPk&feature
=fvw
Cell Analogy:
http://www.youtube.com/watch?v=XAyXNh1iP28
Cell Rap: http://www.youtube.com/watch?v=jtf7MKDBF60
• Both living and non living things are
composed of C.H.N.O.P.S.
• The organization of these molecules into
cells is one feature that distinguishes living
things from all other matter.
• Cell is the smallest unit of matter that can
carry on all life’s functions.
• 1665 Robert Hooke (1635-
Nice Hair!
1703) used the microscope
to examine a slice of cork.
• Coined the term “cells”.
• Anton van Leeuwenhoekcredited with the invention
of the microscope and was
the first person to look at
living cells. (pond water)
• The First Microscope
Developed by three
scientist:
– Matthias Schleiden
(botonist)
– Theodor Schwann
(zoologist)
– Rudolf Virchow
(physician)
1. All living things are composed of one or more
cells.
ex. bacteria is a
single celled living
organism
ex. Plants, human,
dogs, cats, fungus,
protists & insects all
are composed of cells.
2: Cells are the basic unit of structure and
function in an organism.
- Cannot break living things down any
further than a cell. (all of it’s parts have
to function together to carry out
processes)
3: Cells come only from the reproduction of
existing cells. (Theory of Biogenesis)
• Humans only come from humans, cells
only come from cells.
– What is the one exception to this rule?
– Where did the first cell come from.
– One cell was spontaneously created, it
happened once and it will never occur again.
Theory of Spontaneous Generation
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This Theory has been
disproved. We no longer
believe this to be true
because of several very
important experiments.
States that living
things can come from
non-living things.
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Redi’s Experiment helped disprove
the Theory of Spontaneous
http://www.bing.c
Generation.
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video/francescorediexperiment/34f4f6
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=redi's%20experi
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• Now we know that life can only come from
other living organisms. This is called the
Theory of Biogenesis.
And so did Spallenzani and
Pasteur’s experiments.
Two Types of Cells
1. Prokaryote : “Before kernel”
 2. Eukaryote: “True kernel”
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No Organelles “little
organs”
Cell wall made of
peptidoglycan. (Mixture of
proteins and
carbohydrates)
One circular strand of
DNA, found in the center
of the cell (Nucleotide
Space)
Ex: Unicellular Organisms
- Bacteria
Contain Organelles
Many strands of noncircular DNA found in
the nucleus
Ex. Multicellulardogs, cats, insects
Ex. Unicellular:
protists
Four shared characteristics
All Prokaryotic & Eukaryotic cells shared
the following:
1. cell membrane
2. genetic material (DNA &/or RNA)
3. Cytoplasm/cytosol
4. ribosomal material (for protein
synthesis)
Pond water creatures
http://www.youtube.com/watch?v=1cLWK
DhBYxo
Organelle #s related to cell function
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Eukaryotic cells have the same features (organelles)
but depending on their function or purpose they can
have many of one type of organelle.
Liver cell – many
Ribosomes makes
many proteins.
Muscle cell – needs
energy, many
mitochondria
compared to other
cells .
The cell’s structure can also be
related to its function.
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Ex. Nerve Cell
What is the function of a
nerve cell?
Bring info from fingertip to
brain-and back
instantaneously
What do you think a nerve
cell would look like?
Net more surface area,
more area to sense and
feel.
Game of phone, more
people involved message
is confused. Many small
cells message would be
slow and confused.
http://www.cellsalive.com/howbig.htm
Q: Why are cells so small?
A: It has to do with surface-to-volume-ratio. Basically
its so the cell membrane can adequately provide the
interior of the cell with all the nutrients it needs
before it starves while getting rid of all the waste
before the cell is poisoned.
Cells & Surface to Volume Ratio
http://www.youtube.com/watch?v=Jn9oJtXZYcU&feature=pyv&ad=3444868461
&kw=cell&gclid=CLqih7T1saQCFUNM5QodRnhXyw
Increase surface area
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long
small intestine –25 feet
• As a general rule, the smaller
something is, the more membrane or
"SURFACE AREA" it has.
If the nucleus was the
size of a penny, the cell
would be the size of a
football field.
Cell Lifespan
• RBC: 120 days
• Platelets: 10 days
• WBC: 13 days to 1 years depending on the type (
neutrophils: 1 day, granulocytes: 7 to 10 days,
monocytes: 5 to 7 days, lymphocytes: 1 yr)
• Bone: 25 to 30 years
• Stomach lining cells: 2 days
• Skin: 19 to 34 days
• Liver: 22 days
Cell size comparison:
• Brain: a lifetime
http://learn.genetics.utah.edu/content/b
• Sperm: 1 to 3 days
egin/cells/scale/
• Egg: 24 to 48 hrs.
• Colon cells: 3 to 4 days http://www.cellsalive.com/howbig.htm
Cell Membrane
• The entire cell is surrounded by a thin
membrane.
• Cell membrane is considered
selectively permeable.
• Q: What does this mean?
• A: Some things can pass through with
ease, others need some help, and some
cannot pass through at all.
Phospholipids
• Cell membrane contains
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Phospholipids
Phospholipids contain a Polar
Head and a Non polar tail
What does this mean?
part of the phospholipid is
hydrophilic and the tail is
hydrophobic
Lipid Bilayer
• Made of Phospholipids
• Polar heads are on the outside.
• Non-polar tails make up the inside of the
cell membrane
• This forms a lipid bilayer
Cytoplasm/Cytosol
Cytoplasm – is
everything in the cell
from the cell
membrane to outside
the nucleus.
(including organelles)
Cytosol-is just the jellylike substance
between the cell
membrane and the
nucleus.
It is an aqueous
solution (not including
organelles)
Mitochondria
• Is the powerhouse of the cell,
provides the cell with energy.
Site of chemical reactions
that transfer energy from
organic compounds to ATP
(ATP is Energy).
Where did the organic
compounds come from?
Mitochondria
• If this particular cell is involved with
making a lot of energy, the cell will
contain many mitochondria. (muscle cell).
• Each cell may contain as many as 2,500
mitochondria.
Mitochondria
• Mitochondria is surrounded by two
membranes, outer and inner membrane.
• The inner membrane has many folds
called cristae.
• Cristae greatly increase the surface area.
Providing more space for the chemical
reactions that occur in the mitochondrion.
• Matrix-fluid inside the mitochondria
Penicillin
• Penicillin antibiotic medicine
• World War II penicillin made a major difference in the
number of deaths and amputations caused by infected
wounds amongst Allied forces.
• Penicillin interferes with the ability of the cell to make a
proper cell wall.
• Cell wall is comprised of protein and Carbohydrates –
penicillin destroys the protein.
(like pulling the nails out of a house)
Water then flows into the cell, causing the cell wall to
rupture destroying the bacteria
Symbiotic Theory (CP)
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Mitochondria have their own DNA, and new
mitochondria only arise when existing ones grow
and divide
Since they have their own DNA scientists believe
that mitochondria used to be a prokaryotic cell
that lived on it’s own.
But now live in within the cell, cell provides
protection, mito provides energy.
Mitochondria is also the same size as a
prokaryotic cell.
Ribosomes
Most numerous organelles in cells.
Ribosomes are made of two parts- a large
subunit and a small subunit + rRNA
Ribosomes synthesis (make) proteins.
Proteins - are the organic molecules that make
up your body. (enzymes, muscle, organs, eyes
color etc.)
Read the DNA (blueprint) and build protein
House blueprint, copy for plumbing –plumber
can read it and build what is required.
Endoplasmic Reticulum (ER)
• Acts a intracellular highway, a path along which
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molecules move from one part of the cell to
another.
System of membranous tubules and sacs which
contain channels inside to move molecules
around the cell.
The amount of ER inside a cell fluctuates
depending on the cell’s activity. More people in
NJ more roads/highways required
• Rough Endoplasmic Reticulum or Rough ERribosomes are attached right to the ER. Giving it a
rough appearance. (like cars on the road)
• (cell makes a lot of proteins, might as well put the
factory right on the road)
• Liver cells
Smooth ER- no
ribosomes present.
(like no cars on the
road)
Involved in the
synthesis of
steroids in glands.
Rough ER
Smooth ER
Golgi Apparatus
• Processing, packaging, and secreting
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organelle of the cell.
System of membranes-similar to the
ER
Works with the ER
GA – modifies proteins for export by
the cell.
Analogy: English
essay- Ribosome
makes a rough
draft, G.A.
proofreads, fixes
mistakes,
produces the
final draft.
Golgi Apparatus
Relationship
• Ribosome Golgi Apparatus ER
Ribosome makes the protein, GA cleans it
up, gets it ready for shipping and the ER
delivers it to the other part of the cell or
out of the cell.
Ford Car- build a car, detail a car, put it on
the highway to move it around and sell.
Lysosome
• Small, spherical organelles that enclose
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hydrolytic enzymes within membrane bound
sac.
Enzymes can digest Proteins, Carbs, lipids, DNA
and RNA, viruses and bacteria.
Development for humans –webbed fingers,
lysosomes eat away at the webbing before
birth.
Nickname: suicide sac (digests old cells and
recycles the parts)
Enzymes work best in an Acidic Environment, so
they pump in H+ ions.
Lysosome
Cytoskeleton
• Network of long protein strands
located in the cytosol
• Give the cell structure and
shape.
• Microfilaments and
microtubules
• Microfilaments – threadlike
structures made of protein.
• Microtubules-bundles of
filaments.
• You have a skeleton to maintain
your structure, so does a cell.
Golden Gate bridge
• 3 ft, over 27,000 wires inside
Microtubules
Cytoskeleton
Cilia and Flagella
• Hair like extensions from the cells surface.
• Flagella-help move the cell.
• Cilia-beat around the cell to move organic
molecules closer to the cell. (think of a
ball in the middle of a pool)
Nasal Cilia
Flagella
Nucleus
• Most prominent structure within a
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eukaryotic cell.
Nuclear Matrix – protein skeleton
within the nucleus.
Nuclear envelope-nucleus is
surrounded by a double membrane.
DNA- is contained in the cell.
(protected) never leaves the nucleus
Nuclear pores-small holes in the
nuclear envelope
Nucleolus –ribosomes are synthesized
and partially assembled before they
pass out the pores and into the cytosol.
Name 2 things that can pass through
the nuclear pore?
- Ribosome parts, RNA
Nucleus
Nuclear Envelope
Nuclear pore
Plant Cell
 Plant cell contains everything an
animal cell has + Cell Wall,
Vacuoles and Chloroplast.
 Cell Wall- rigid structure made of
cellulose and pectin for support
and structure.
 Vacuoles – large storage area for
the cell.
 Chloroplast – site of
photosynthesis filled with
chlorophyll