Transcript 1617-cytology - Cobb Learning

So…now that you know what a
“living thing” is…
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2.
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4.
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Is made of one or more_________.
Is composed of certain_________.
_________&__________.
__________to a __________.
Requires_________.
_____________
And you know what living things
require…
______________
2. ______________
3. ______________
4. ______________
And remember, not all living things need “air” but
the gases are important.
1.
So…what about these here cells? What exactly
are they? Okay…I’ll tell ya…in a minute 
How All of This “Stuff” Fits Together
Organisms: a person, a fish, a lizard, a tree,
an amoeba
Organ Systems: Circulatory, Respiratory, etc.
Organs: Stomach, lungs, gills, heart, brain.
Tissues: vascular, nerve, muscle.
Cells: the basic unit of structure and function!
Organelles: Structures within a cell that perform specific functions
Cells…what are they?
What’s in ‘em?
• First of all, the study of cells is called…
CYTOLOGY
The Cell Theory
1. All organisms are made of one or
more cells. (Schleiden & Schwann)
2. The cell is the basic unit of all living
things. (Schleiden & Schwann)
3. All cells come from existing cells.
(Rudolph Virchow).
Important Folks
1. Robert Hooke 1674- was the first dude
to observe cells.
• Observed dead cork cells under a simple
microscope,
• Saw the compartment like structure, he
termed the different “compartments”
cells…ipso facto…CELLS.
• 2. Anton van Leeuwenhoek: 1674
• “Father of Microscopy”
• Checked out cells in living algae. He
proved that that living things were made
up of cells.
• First to look at bacteria
• 3.Theodor Schwann and Matthias
Schleiden: 1839-ish
• First two components of the cell theory.
• Rudolph Virchow (late 1800’s): Final part
of the cell theory.
Surface Area to Volume Ratio
• This explains why cells don’t get bigger than
they do.
• As a cell grows, the inside of the cell (its
volume) grows at a greater pace than the outer
surface of the cell membrane (its surface area).
• If the cell grew too large, nutrients could not get
in fast enough and waste couldn’t get out fast
enough.
Two Major Types of Cells
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Prokaryotic
Single celled organisms
with no nucleus or
membrane-bound
organelles.
Earliest appearing cells.
Bacteria-most common
Archaea-tough little
buggers that can live
where nothing else can.
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Eukaryotic
Uni or multicellular
Have a nucleus and
membrane-bound
organelles.
Larger than prokaryotic
cells (about 10x on
average).
Animals, plants, fungi,
and protists.
Prokaryote v Eukaryote
Prokaryotes
Both
Bacteria and Archaea
Cell Membrane
Smaller
Appear Earlier
Circular DNA in
Nucleoid
Cell Wall (some Euk)
Ribosomes
DNA
Eukaryotes
Animal, plant, fungi,
protists
Larger
Appear later
Linear DNA in
Nucleus
No Membrane-bound
organelles
Reproduce by Cell
division
Reproduce by binary
fission
Cytoplasm
Reproduce by Mitosis
Flagella
Larger ribosomes
Simple Cell Walls (if
present)
Smaller ribosomes
Complex Cell Walls
Membrane-bound
organelles
What’s in a Cell?
Another view
Animals, Plants, Protists, & Fungi
Archaea
Bacteria &
WHAT'S IN A CELL
Organelles
(the working parts that are inside of cells)
You know how there are organs in your body that do “things?”
Well, organelles do similar things in cells.
 Like…your brain controls what your body does…right? There’s
an organelle in a cell that controls this stuff. How? Well…it’s
biochemical…but…you’ll get there
 Anyway, that’s an ANALOGY, which is…
“a comparison between two things, typically on the basis of their
structure and for the purpose of explanation or clarification.”
 Some have a covering called a membrane. These are referred
to as membrane-bound organelles. We’ll call ‘em MBO’s for
short.
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Cell Membrane
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AKA Plasma membrane or plasmalemma.
Two layers of phospholipids…a phospholipid
bilayer.
Separates the cell from the environment.
Selectively permeable…that means it can “let stuff
through” and “keep other stuff out.” Sweet!
This thing makes chemical “decisions” about what
can enter or leave.
Analogy: it’s like a security guard. “You can come
in but yer friend’s gonna have to wait outside.”
Which types of cells? All types!
Nucleus
 This
is the “brain” or “CPU” of the cell.
It controls all of the cell’s functions and
contains the DNA (which determines
heredity).
 Analogy: Well, a brain or CPU…like I
said.
 Which types of cells? All types of
EUKARYOTIC cells.
Mitochondria
This is where CELLULAR RESPIRATION takes
place. You know…energy from food…ATP
production. The more of these you find in the
cell, the more ATP is being produced.
 Analogy: It’s like a battery in an I-Pad.
 Which types of cells? All types of
EUKARYOTIC cells.
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There is a theory that supports the idea that these organelles
were once actual organisms that lived in other organisms in a
mutualistic symbiotic relationship! This is called the endosymbiont
theory.
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Chloroplasts
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This is where PHOTOSYNTHESIS takes place.
You know…food from energy…using the SUN.
Analogy: Sorta like bread cooking in an oven...it
uses the heat energy to react ingredients, which
turns it from dough to bread.
 Which types of cells? Certain types of
EUKARYOTIC cells…plants, algae, and some
bacteria.
Cell Wall
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This is wall (duh) outside of the cell membrane. Not
all cells have one, but it’s function is to provide
structure and protection.
Analogy: Like a chainlink fence around a compost
pile.
Which types? All Types
…and composition…
Plant cells-cellulose
Fungi-Chitin
Bacteria-peptidoglycan (protein/sugar)
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Cytoplasm
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This is actually a bunch of stuff. A
gel matrix full of water, nutrients,
gases, structures, and wastes.
Essentially, it is all of the cell’s
contents except the nucleus.
Analogy: If the school was a cell and
the office was the nucleus, the
cytoplasm would be everything inside
the walls of the school…except for the
office.
Which type of cells? All types!
Ribosomes
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These are really small (they’re
measured in Svedbergs…I did NOT make
that up).
They are the organelle in which
proteins are made (that’s called
protein synthesis).
Analogy: In a factory…whomever
assembles the parts to make the final
product…they’re the ribosomes!
Which types of cells? All types!
Endoplasmic Reticulum
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Imagine that you crumpled up a piece of giant piece of newspaper and
could get it inside of a beach ball. That’s kind of what the ER is.
Instead of newspaper…it’s a network of membranes.
Substances like nutrients and wastes move along the surface to get from
one place to another within a cell.
There’s smooth ER and rough ER. The rough ER has ribosomes stuck in
it. How convenient for transporting proteins around the
cell…donchathink?
Analogy: The floors in our school. You can move along them to get
around.
What types of cells? Eukaryotic
Golgi Bodies
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These are related to the ER, but they are
stand-alone (they’re not all connected).
They take substances (like proteins), wrap
them in membrane material, and send them
out to other parts of the cell.
Analogy: The US Post Office takes your mail,
puts it in a truck or on a plane, and delivers
it.
What types? Eukaryotic
Vacuole
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These are a type of vesicle (like a plastic
bag) that holds and stores stuff.
Food Vacuoles store…uhhh…food.
Water Vacuoles store…yup!
Contractile Vacuoles help keep the proper
balance of water inside and outside of
certain cells.
Analogy: Like a refrigerator or water
cooler in an office.
What types? Eukaryotes
Lysosomes
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These are small organelles that break
down waste substances and old
organelles that don’t work anymore.
Analogy: They’re like little recycling
bins or garbage disposals.
Which types? Eukaryotes!
Cytoskeleton
Made of protein
 Acts as a “muscle”
and a “skeleton”
for the cell
 Keeps cell membrane
collapsing and
cells
move
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from
helps some
The stuff from this point on will
not be on this test.
That does not render the
information insignificant…ya just
don’t gotta worry about it right
now.
Chemical Compounds in the Cell
Remember what a compound is…huh…do ya?
It’s two or more elements that are
CHEMICALLY combined. They lose their
individual properties and take on a completely
new identity…but you knew that right ?
 Just to refresh your memory…
Elements: substance composed of only one type of
atom. Hint: if it ain’t on da periodic table…it ain’t an
element.
Atoms: smallest amount of an element that you
can have.
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Types of cellular compounds
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Organic: These are compounds that contain
carbon.
Inorganic: Umm…they don’t have carbon
(with the exception of CO2, which has C but
isn’t organic...go figure).
How to tell the difference…
C6H12O6…Yup!
 KMnO4…Nope!
Got It…Good 
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Proteins
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Large organic molecules.
Composed of carbon (C), nitrogen (N),
hydrogen (H), and sometimes sulfur (S).
Proteins are essential (important) for cell
membranes, muscle tissue, and organelles within
cells.
Made up of AMINO ACIDS, which are smaller
molecules that link together to make the larger
protein molecule.
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There are many amino acids but there are some
are ESSENTIAL.
The 20 are combined in many ways to make
different proteins.
ENZYMES
A special type of protein that speeds up
chemical reactions in cells.
Enzymes can be recognized by the –ase at the
end of their name. Example: salivary amylase is
the enzyme that starts digesting starches in your
mouth.
20 Standard Amino Acids (no…not
mean old acids…AMINO ACIDS!)
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Essential (your body needs to get them from
food): Arginine, Isoleucine,Leucine, Lysine,
Methionine, Phenylalanine, Threonine,
Tryptophan, Valine, Histidine
Nonessential: Alanine, Asparagine, Aspartate,
Cysteine, Glutamate, Glutamine, Glycine,
Proline, *Serine, *Tyrosine
Carbohydrates
(carbon/water)
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These are: sugars and starches, (also saccharides, and
polysaccharides…but don’t worry about those right
now).
CHO’s called sugars are products of photosynthesis.
Sugar molecules can combine to form starches.
CHO’s are high in energy…so…we eat ‘em. We’ll
learn how you use them later.
Hint: Whole grains GOOD Too many simple sugars
BAD 
Lipids
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Fats, oils, and waxes are lipids.
Also made up of C, H, and O.
These have LOTS of energy, and if it isn’t used
it gets stored.
When you see words like: fatty acids, glycerides,
and phospholipids…you’re reading about lipids.
Instead of calling someone a fat-head…call ‘em
a “phospholipid-head…folks’ll think you’re all
sciency n’ smart.