Biology Journal 9/14/12
What molecule is the
macromolecule DNA made
out of?
How did that molecule get its
name?
Biology Journal 9/20/10
What do ribosomes do?
What other organelle are
ribosomes often attached to?
What does that organelle do?
Biology Journal 11/21/13
How many
cells do you
think are in
the average
human’s
body?
Biology Journal 11/21/13
How is this picture like the endosymbiotic theory?
What was some of the evidence for the
endosymbiotic theory?
Biology Journal 11/22/13
What are histones?
What are chromosomes?
What’s the difference between the DNA of a
eukaryote and the DNA of a prokaryote?
2.2 Prokaryotic Cells
Assessment statement
2.2.1 Draw and label a diagram of the ultrastructure of Escherichia
coli (E. coli) as an example of a prokaryote.
 cell wall, plasma membrane, cytoplasm
 pili, flagella, ribosomes
 nucleoid (region containing naked DNA)
2.2.2 Annotate the diagram from 2.2.1 with the functions of each
named structure.
2.2.3 Identify structures from 2.2.1 in electron micrographs of
E. coli.
2.2.4 State that prokaryotic cells divide by binary fission.
2.3 Eukaryotic Cells
Assessment statement
2.3.1
Draw and label a diagram of the ultrastructure of a liver cell as an example of an animal cell.
 free ribosomes, rough endoplasmic reticulum (RER)
 lysosome, Golgi apparatus
 mitochondrion, nucleus
2.3.2
Annotate the diagram from 2.3.1 with the functions of each named structure.
2.3.3
Identify structures from 2.3.1 in electron micrographs of liver cells.
2.3.4
Compare prokaryotic and eukaryotic cells.
 naked DNA versus DNA associated with proteins
 DNA in cytoplasm versus DNA enclosed in a nuclear envelope
 no mitochondria versus mitochondria
 70S versus 80S ribosomes
 eukaryotic cells have internal membranes that compartmentalize their functions
2.3.5
State three differences between plant and animal cells.
2.3.6
Outline two roles of extracellular components.
 The plant cell wall maintains cell shape, prevents excessive water uptake, and holds the
whole plant up against the force of gravity.
 Animal cells secrete glycoproteins that form the extracellular matrix. This functions in
support, adhesion and movement.
Cells: The Basic Units of Life
Nucleus
• Contains the DNA
• Has a nuclear membrane
In most cells the nucleus is the easiest
organelle to see
White blood cells
Muscle Cells
Red blood cells,
these don’t have
a nucleus
Nucleus means “middle”
it’s used in many ways in science
Mitochondria
• Makes energy for the cell
through a reaction called
cellular respiration
• uses up oxygen and sugar
for fuel
What kinds of cells might need
a lot of energy?
Muscle cells have lots
of mitochondria
What other kinds of cells might
need a lot of energy?
Neurons (brain and nerve cells) use energy to
send electrical signals
What other kinds of cells might
need a lot of energy?
What kinds of cells don’t need a lot of
energy?
Bone cells
Fat cells (adipose tissue)
Ribosomes
• Make protein through translation
• Made out of rRNA
Endoplasmic Reticulum
• Membranes that send
proteins to where they need
to go using chemical signals
– Rough E. R. has ribosomes on it
– Smooth E. R. does not have
ribosomes on it.
E. R. is like a postal
carrier, sending
proteins to where they
are supposed to go.
Endoplasmic Reticulum
• Rough and smooth are connected.
• The Rough has ribosomes on it like
rhinestones on a shirt.
Golgi Complex / Apparatus
• Packages up molecules in a sac
called a vesicle and sends them to
where they need to go using
chemical signals
Camillo Golgi,
winner of
Nobel prize in
medicine in
1906; winner
of world’s
sexiest
moustache
competition in
1907.
Vacuole
• A sack for storing
water and
nutrients. Like a
storage tank. Most
plant cells have 1
large vacuole
Why might plant cells store
lots of water in vacuoles,
but animal cells don’t?
Chloroplast
• Uses sunlight to make sugar molecules
(photosynthesis)
• Contains green pigments (chlorophyll)
• Plants only
Lysosome
• Breaks down and digests large
pieces of food, or unneeded
organelles, using acids and
enzymes
• Animal cells tend to have
many. Plant cells rarely do.
In what tissues might we find a
lot of lysosomes?
Digestive Cells
What other cells might we find
a lot of lysosomes?
Bacteria trying to
out-run a white blood
cell. If the white
blood cell gobbles up
a bacteria, it sends
the bacteria to a
lysosome to be
digested.
Cytoplasm
• The jelly-like substance
that takes up the space
inside a cell.
Cytoplasm is chalked full of
molecules that the cell uses.
Cell Membrane
( aka Plasma membrane)
• The “skin” of a cell.
Controls what enters and
leaves through transport
proteins.
Cell Membrane
( aka Plasma membrane)
• It’s made out of two
layers of lipids called
phospholipids.
Plant Cell Wall
• Hard structure made out of carbohydrates.
• Makes plant cells strong and sturdy, but
prevents them from moving
• Plants only!
Bacterial Cell Wall
• A tough structure made out of peptidoglycan
(a protein-carbohydrate substance)
• In some bacteria, this cell wall can be stained
and identified (called gram-positive bacteria),
and in some bacteria the cell wall can’t
(called gram-negative bacteria)
Flagella
• A whip-like tail for swimming through liquid.
There are 2 basic kinds of cells
1. Prokaryotes
• Bacteria
• Have 1 circular
piece of DNA
• No organelles!
• Small and
simple, so they
can multiply
fast!
There are 2 basic kinds of cells
2. Eukaryotes
• Have many pieces of
linear DNA (in lines)
• Have organelles!
• Bigger and more
complex
• Anything multicelluar
is a eukaryote
(including you)
Eukaryotes are about 100 times
bigger than prokaryotes
Biology Journal 11/26/2013
Compare and contrast eukaryotes and prokaryotes in a
Venn diagram.
Eukaryotes
Both
Prokaryotes
Biology Journal 11/26/2013
Compare and contrast eukaryotes and prokaryotes in a
Venn diagram.
Eukaryotes
Both
Prokaryotes
•Large and more complex
•Have a cell membrane
and cytoplasm
•Small and simple
•Has a nucleus and
organelles
•Reproduce through
asexual cell division
•Lacks a nucleus and lacks
organelles
•DNA is linear and in
many pieces
(chromosomes)
Have ribosomes (but they •DNA is circular and in
are different)
one piece (usually)
•Cells divide through
mitosis
•Cells divide through
binary fission
•Have 80s ribosomes
•Have 70s ribosomes
•Attaches and transfers DNA
through pili
Identify the structures in this false-colored microscopic image of a human liver cell
Cytoplasm
Mitochondria
Ribosomes
(free)
Plasma
membrane
Nucleus
Endoplasmic Reticulum
(rough)
Lysosome
Identify the structures in these false-colored microscopic images
Cell membrane
Cell wall
Cytoplasm
(the darker spheres are ribosomes)
Pili
Flagella
Nucleoid region
(where DNA is located)
Extracellular Components – parts outside of the cell
The cell wall of plants
•Gives the cell shape
•Holds the cell up against
gravity
•Prevents it from exploding
from too much water
Glycoproteins of animals
•Made out of carbohydrates
attached to proteins
•Gives the cells adhesion
•Anchors the cell to
surrounding cells
•Allow for movement