The Cell
#1
Mitochondria
Mitochondria
Nickname:
Batteries
Structure:
“bean” shaped
Function:
provides energy for
the cell
(powerhouse of the cell)
Mitochondria
#2
Nucleus
Nucleus
Nickname:
Brain
Structure:
-central, large sphere
-surrounded by a nuclear
membrane
-contains the chromosomes
(DNA)
Function:
-controls all cell activity
Nucleus
Chromatin
Mitochondria
Endoplasmic
Reticulum
#3
Endoplasmic
Reticulum
Endoplasmic Reticulum
Nickname:
Subway System
Structure:
-tubes that connect the nucleus
to the cytoplasm
-Rough ER has ribosomes
-Smooth ER has NO ribosomes
Function:
-transports materials
Rough
Endoplasmic
Reticulum
Has ribosomes
#4
Cell Membrane
Cell Membrane
Nickname:
skin
Structure:
-has 2 layers
-it is the outer boundary
Function:
1) Holds the cell together
2) Controls what goes in and
out of the cell
#5
Golgi Bodies
Golgi Bodies
Nickname:
Packaging Factory
Structure:
-folds of membrane
Function:
-packages materials for
transport
#6
Lysosome
Lysosome
Nickname:
Stomach
Structure:
-small sphere
-contains digestive juices
Function:
-digests molecules
Lysosomes
#7
Vacuole
Vacuole
Nickname:
Suitcase
Structure:
-large bubble like container
Function:
-stores food or waste
Vacuoles
#8
Cytoplasm
Cytoplasm
Nickname:
?
Structure:
-jelly like fluid that fills the
cell
Function:
1) gives the cell shape
2) contains nutrients/food for
the cell
#9
Leave it blank for now
#10
Nucleolus
Nucleolus
Nickname:
brain in a brain
Structure:
-small sphere inside nucleus
Function:
-control center for nucleus
Nucleus
Nucleolus
Movie: Parts of an Animal Cell
Plant Cells vs. Animal Cells
Similarities & Differences
Plant Cells vs. Animal Cells
Similarities & Differences
Similarities
-nucleus
-cell membrane
-cytoplasm
These are the most
important organelles b/c
they all cells have them.
Plant Cells vs. Animal Cells
Similarities & Differences
Differences
Animal Cell
Plant Cell
Round shape
Lysosomes
No cell wall
No chloroplasts
Square shape
No lysosomes
Cell wall
Chloroplasts
Cell Specialization
Cells vary in:
-shape
-size
-internal structure
Why is this important?
-different cells perform different
functions
Nerve Cells
Nerve Cells
Characteristics:
-very long
allows messages to
go from brain to hand
-branching
messages sent to coordinate many
activities all at the same time
Skeletal Muscle Cell
Skeletal Muscle Cell
Characteristics:
-very long
-many nuclei
lots of nuclei to control the whole
length of muscle
-many mitochondria
muscle requires a lot of energy
Red Blood Cells
Red Blood Cells
Characteristics
-concave shape
-very small
allows cell to bend in order to fit
through tiny blood vessels
Movie: Types of Human Cells
How do things get in and out
of the cell?
The cell membrane
“controls what goes in and out of the cell”
a.k.a.
Selective Permeability
Selective: “choosy”
Permeable: “porous” or “has holes”
Ex: rain coat is not permeable
Sweater is permeable
The cell membrane must be permeable
(have holes in it) because:
1.
2.
Nutrients, water and oxygen must enter
Waste must exit (a build-up is toxic!)
The cell membrane is selective because:
1.
Not everything can enter or exit
(ex: viruses)
Molecules that must be
able to get in and out
of the cell
Nutrients
Oxygen
Water
Waste
Virus
Entering & Exiting
There are 3 ways to enter and exit the
cell:
1. Diffusion
Passively
(no effort from the cell)
2. Osmosis
3. Endocytosis
Actively
a. Phagocytosis
b.
Pinocytosis
(cell makes it happen)
1. Diffusion
The movement of molecules from an area
of high concentration to an area of low
concentration
2. Osmosis
The movement of water from an area of
high concentration to an area of low
concentration
3. Endocytosis/Exocytosis
Sometimes, molecules are too large to
pass through the cell membrane.
Endocytosis is used for large molecules to
enter a cell.
a) Phagocytosis Æ cell “eating”
b) Pinocytosis Æ cell “drinking”
Exocytosis is used for large molecules to
exit a cell.
Endocytosis
Endocytosis
The cell membrane invaginates (forms a
pocket) which engulfs the large molecules
and brings them into the cell.
Movie: Endocytosis & Exocytosis
Movie: The Double Helix
DNA
DeoxyriboNucleic Acid
DNA is genetic
information.
The “blueprint” for
the development &
appearance of every
living thing.
Shape: Double helix
Chromosomes are made up of DNA
They are found in the nucleus
Chromosomes
Humans have
exactly 46
chromosomes.
2 Categories of Cells
Somatic Cells
(body cells)
Ex:
skin cells
bone cells
These cells are diploid
Æ 46 chromosomes
Divide by Mitosis
But what happens when a baby
is made?
A baby is created from a sperm & an egg
Does that mean the baby has
46 + 46 chromosomes (total: 92)?
What has to happen for a baby to get only
46 chromosomes?
2 Categories of cells
Somatic Cells
(body cells)
Ex:
skin cells
bone cells
Gametes
(reproductive cells)
Ex:
sperm cells
ovum (egg cells)
These cells are diploid
Æ 46 chromosomes
These cells are haploid
Æ 23 chromosomes
Divide by Mitosis
Divide by Meiosis
But what happens when a baby
is made?
Since the sperm and egg have only half of
the necessary chromosomes (23 each)
together they will create a baby with
exactly 46 chromosomes .
In order to produce more cells,
cells divide
2 types of
Cell Division:
-Mitosis
-Meiosis
Do Somatic Cells Need to
Reproduce?
Do Somatic Cells Need to
Reproduce?
Yes!
„
„
„
To replace old cells
To replace damaged cells
For growth
Mitosis
(somatic cells)
1.
2.
Everything inside the cell is duplicated
(copied).
The cell then divides into two identical
cells.
These cells are identical in every way.
They are clones.
They are diploid.
Mitosis
Chromosomes
are duplicated
Cell Division
occurs (Mitosis)
Meiosis
(reproductive cells)
1.
2.
Everything inside the cell is duplicated
(copied).
The cell then divides TWICE to form 4
cells with half the number of chromosomes
These are the gametes
(egg and sperm cells)
They are haploid
Meiosis
Chromosomes
are duplicated
1st Cell Division
2nd Cell Division
Movie: Mitosis
Phase 1: Interphase
1. Each
chromosome makes a copy of itself
2. Chromosomes still appear as Chromatin
Phase 2: Prophase
1.
2.
3.
Chromosomes now visible
Spindle fibers stretch across the cell
Nuclear membrane disappears
Phase 3: Metaphase
1.
2.
Chromosomes line up at center of cell
Spindle fibers attach to chromosomes
Phase 4: Anaphase
1.
Spindle fibers pull chromosome pairs
apart towards opposite sides of cell
Phase 5: Telophase
1.
2.
Nuclear membrane reappears
Cell pinches apart to form 2 new cells
Movie: Meiosis