Transcript cells

Cells
Since every living thing is made of cells,
does that mean bigger organisms (like
whales or elephants) have bigger cells?
•
• Not really!
All organisms, no matter how tiny or how large are
composed of cells.
•
There are different TYPES of cells (ex. Skin, bone, muscle,
nerve), but all cells of a particular type are essentially the
same size.
•
Therefore, the difference in cells in large vs. small
organisms is the NUMBER of cells, not the SIZE!
How Were Cells
Discovered?
• New technologies lead to new
discoveries
• Robert Hooke - invented the
first microscope and was the first
to observe and name the small
units that make up organisms.
He called those small units cells
because of the appearance of the
structures in the dead cork he
observed.
How Were Cells
Discovered?
• Anton van Leeuwenhoek improved the microscope
and procedures for observing
cells. He was able to clearly
see living cells when
observing the scrapings from
his teeth.
Fill It In …
Cells observed by …
• Hooke:
• Leeuwenhoek:
The Cell Theory
Through the cooperative efforts of
many individual scientists, a
unifying cell theory developed:
• All organisms are made of cells
• Cells are the structural &
functional units of organisms
• Cells come from pre-existing
cells
The Cell Theory
Prokaryotic vs Eukaryotic Cells
• Are all cells
alike?
• Two main types
of cells ….
Prokaryotic Cells
• Simplest type of cell
• Includes only bacteria.
• Structure of a prokaryotic cell
• No nucleus
• No membrane-bound
organelles
• Includes: circular
chromosome (DNA),
plasmids (smaller rings
of DNA, and ribosomes
Prokaryotic Cells- MYP
• Thought to have a symbiotic relationship
with Eukaryotic Cells
• Nucleus
• Mitochondria
• Chloroplasts
Eukaryotic Cells
• More complex than prokaryotic
cells
• Includes protist cells, fungi cells,
plant cells, and animal cells (i.e. everything EXCEPT bacteria cells)
• Structure of a eukaryotic
cell
• Chromosomes contained
within a nucleus
• In addition to ribosomes
contains membrane-bound
Cells :)
Fill It In …
Prokaryotic
Eukaryotic
Check Yourself!
1. Who first to observed dead cells?
Who first to observed living cells?
2. What are the two main types of cells?
3. How is the location of the DNA different in
prokaryotic and eukaryotic cells?
Check Yourself!
1. Who first to observed dead cells? HOOKE
Who first to observed living cells? LEEUWENHOEK
2. What are the two main types of cells?
3. How is the location of the DNA different in
prokaryotic and eukaryotic cells?
4. What is cell specialization?
5. In cells, form relates to ________________.
Check Yourself!
1. Who first to observed dead cells? HOOKE
Who first to observed living cells? LEEUWENHOEK
2. What are the two main types of cells?
PROKARYOTIC & EUKARYOTIC
3. How is the location of the DNA different in
prokaryotic and eukaryotic cells?
4. What is cell specialization?
5. In cells, form relates to ________________.
Check Yourself!
1. Who first to observed dead cells? HOOKE
Who first to observed living cells? LEEUWENHOEK
2. What are the two main types of cells?
PROKARYOTIC & EUKARYOTIC
3. How is the location of the DNA different in
prokaryotic and eukaryotic cells? EUKARYOTIC
CELLS KEEP THE DNA INSIDE A NUCLEUS
4. What is cell specialization?
5. In cells, form relates to ________________.
What do cells share?
Structures found in ALL
cells
DNA/Chromosome(s)
• DNA organized as
chromosome(s).
DNA directs cell
activity
Cytoplasm
• Cytoplasm is the
“filling” of the cell
and is made of up to
90% water. Water
provides the
necessary
environment for all
the chemical reactions
the cell needs
Ribosomes
• Ribosomes are
organelles that are the
site of protein
synthesis. Proteins
are essential for
enzymes, structure,
and communication
• Uses DNA code to
synthesize proteins
Cell Membrane
• Also called the Plasma Membrane
Fill It In …
4 structures found in ALL cells:
1.
2.
3.
4.
Cell Membrane
• Composed of a
phospholipid bilayer
with embedded
proteins. The fluid
mosaic model
describes the
structure of the cell
membrane
Cell Membrane
• Fluid - individual
phospholipids and
proteins can move past
each other; they are not
fixed in one position
• Mosaic - the membrane
has more than one type
of molecule
(phospholipids &
proteins)
Cell Membrane- MYP
• Flexible/strong barrier
• Some proteins from channel or pumps to
allow things to go in and out of the cell
• Carbohydrates are attached to membrane
• These are used as chemical identification
markers for the cell
Functions of the Cell
Membrane
• Selectively permeable
- regulates what enters
and leaves the cell.
This helps maintain
homeostasis
• Gives the cell
(cytoplasm) shape
Fill It In …
The cell membrane is also called …
And is S____________ P_____________
Structures (organelles)
found in EUKARYOTIC
cells
Fill It In …
Organelle means …
1. Nucleus
• Nucleus - surrounds
the chromosomes for
additional protection;
is made of a
phospholipid bilayer
Nucleus- MYP
• Surrounded by nuclear envelope (lipid bilayer)
• Nuclear pores
• Chromatin- DNA bound to proteins
• Chromosomes are condensed chromatin
• Nucleolus- dense region where ribosomes are
synthesized
2. Mitochondria
• Mitochondria - site of
cellular respiration which
produces cell energy (ATP)
• Active cells (muscle) -> hundreds of
mitochondria
• Inactive cells (fat) -> few mitochondria
• Structure contains folded
membranes which increases
surface area allowing more
space for more reactions
• (MYP)-inherited through the ovum
3. Vacuole
• Vacuoles - store food,
waste or water to be
used inside the cell or
excreted from the cell.
• Size differs in plant vs.
animal cells
• Much, much larger in
plant cells … why?
4. Lysosomes
• Lysosomes - contain
digestive enzymes
which digest food
contained in vacuoles
as well as old or
damaged cell parts
• (contain lipid bilayer)
5. Endoplasmic Reticulum
(ER)
• ER - a series of
interconnected
folded membranes
that function in
modifying
(changing) proteins,
detoxification of
alcohols, and
communication
ER (MYP)
• Lipid components of the cell membrane are
made here
• Proteins and other material are exported or
inserted into the cell membrane
Two Types of ER
• Rough ER
• Covered in
ribosomes
• Modify proteins
Two Types of ER
• Smooth ER
• Lacks ribosomes
• Detoxification
6. Golgi Complex
• Golgi Complex
- packages
materials for
export from cells
• (MYP)- Modify,
Sort, and Package
• “finishing touches”
Plant Cell
versus
Animal Cell
Structures found ONLY in plant
and plant-like cells
• Chloroplasts organelles full of
chlorophyll that are the
site of photosynthesis
which produces sugars
(C6H12O6)
• Composed of folded
membranes for more
surface area
Structures found ONLY in plant
and plant-like cells
• Cell Wall provides extra
support, protection,
and shape for the
cell
• Found outside the
cell membrane and
made of cellulose
Structure found ONLY in animal
cells
• Centrioles organelle that
helps with cell
division in
animal cells
Cytoskeleton (MYP)
• Protein filaments to help maintain shape
• May help with movement (amoeba)
• Microtubules help with cell division (pulling the
chromosomes)
Fill It In …
Summary of structure/function:
Nucleus Mitochondria Vacuole Lysosome ER Golgi Chloroplast -
Fill It In …
Plant only
Animal only
Check Yourself!
1. What four structures are found in all cells?
2. What is the function of the mitochondria?
3. What is the function of the ribosome?
4. What term refers to small cell structures?
5. What two structures are found in plant and plant-like
cells?
Check Yourself!
1. What four structures are found in all cells? DNA,
CYTOPLASM, RIBOSOMES, CELL MEMBRANE
2. What is the function of the mitochondria?
3. What is the function of the ribosome?
4. What term refers to small cell structures?
5. What two structures are found in plant and plant-like
cells?
Check Yourself!
1. What four structures are found in all cells? DNA,
CYTOPLASM, RIBOSOMES, CELL MEMBRANE
2. What is the function of the mitochondria? CELLULAR
RESPIRATION/MAKE ENERGY FOR THE CELL
3. What is the function of the ribosome?
4. What term refers to small cell structures?
5. What two structures are found in plant and plant-like
cells?
Check Yourself!
1. What four structures are found in all cells? DNA,
CYTOPLASM, RIBOSOMES, CELL MEMBRANE
2. What is the function of the mitochondria? CELLULAR
RESPIRATION/MAKE ENERGY FOR THE CELL
3. What is the function of the ribosome? PROTEIN
SYNTHESIS
4. What term refers to small cell structures?
5. What two structures are found in plant and plant-like
cells?
Check Yourself!
1. What four structures are found in all cells? DNA,
CYTOPLASM, RIBOSOMES, CELL MEMBRANE
2. What is the function of the mitochondria? CELLULAR
RESPIRATION/MAKE ENERGY FOR THE CELL
3. What is the function of the ribosome? PROTEIN
SYNTHESIS
4. What term refers to small cell structures?
ORGANELLES
5. What two structures are found in plant and plant-like
cells?
Check Yourself!
1. What four structures are found in all cells? DNA,
CYTOPLASM, RIBOSOMES, CELL MEMBRANE
2. What is the function of the mitochondria? CELLULAR
RESPIRATION/MAKE ENERGY FOR THE CELL
3. What is the function of the ribosome? PROTEIN
SYNTHESIS
4. What term refers to small cell structures?
ORGANELLES
5. What two structures are found in plant and plant-like
cells? CHLOROPLAST & CELL WALL