Transcript Aim: How are cells structured to carry out all of life`s processes?

Ch 7.2: Cell Organelles
• Aim: How are cells structured to carry out
all of life’s processes?
What functions do cells carry
out?
• The structure of cells (organelles or tiny organs) carry
out the following purposes:
1. Provide protection and support
2. Form barrier between the cell and its environment
3. Building and repairing cell parts
4. Transporting materials
5. Storing and releasing energy
6. Getting rid of waste materials
7. Reproduction
How are your cells like factories?
Animal Cell
Plant Cell
Cell Wall
• Definition
– Outermost boundary
of plant cells made up
of cellulose
(carbohydrate)
• Appearance
– Stiff and solid
• Function
– Protection
– Support
– Shape
Cell Membrane
• Definition: The outer
covering of the animal
cell
• Appearance
– Thin
– Contains pores or
microscopic holes
– Contains cholesterol
Cell Membrane-cont’d
• Functions
– Protection
– Support & strength
– Selectively permeable
• Proteins in the
membrane control
movement of materials
into and out of the cell
The Phospholipid
What can enter a cell through
the cell membrane?
• Many small particles
• Water
• Glucose (need help from proteins)
What does not enter a cell
through the cell membrane?
• Large molecules (protein, starch) must be
digested into smaller molecules first
• Waste
Cytoplasm
• Definition
– Constantly moving gellike substance inside a
cell (primarily water)
• Appearance
– Gel-like (Jell-O)
• Function
– Organelles are
suspended in
cytoplasm
– Medium for chemical
reactions to occur
Nucleus
• Definition
– Control center, brain,
computer of the cell
• Appearance
– Large, oval, bound by a
nuclear membrane
(envelope)
• Function
– Regulates or controls all
activities of the cell
• Contains DNA as
chromosomes
Nucleus: Nuclear Membrane
• Definition
– The membrane
surrounding the
nucleus
• Appearance
– Contains pores
• Function
– Controls movement of
materials into and out
of the cell
Nucleus: Chromosomes
• Definition
– Carry genetic information
DNA
• Appearance
– Rodlike
• Function
– Direct all cellular activities
& protein production
– Carry blueprints for life
(DNA/genes)
Nucleus: Chromosomes
• Structure
– Made up of nucleic acids
that bind together to make
protein
– DNA: stores genetic
information inside the cell
– RNA: reads the information
and carries the message
out of the nucleus to the
rest of the cell organelles
Nucleolus
• Definition
– “little nucleus”
• Appearance
– Small round body
inside the nucleus
• Function
– Contains protein and
RNA
– Site of ribosome
production
Ribosomes
• Definition
– Grainlike body made
up of RNA and can be
attached to the
endoplasmic reticulum
(ER)
• Appearance
– Tiny bumps or circles
on the ER or floating
free in the cytoplasm
• Function
– Site of protein
synthesis (for growth &
repair)
Endoplasmic Reticulum (ER)
• Definition
– Clear tubular passageways
leading out of the nuclear
membrane
• Appearance
– Ribbon-like (some with
dots)
• Function
– Transport within the cell
Rough ER vs. Smooth ER
• Has ribosomes
attached
• Produces proteins
• Lacks ribosomes
• Produces lipids &
hormones
Mitochondria
• Definition
– the “Power-house” of the
cell providing energy
• Appearance
– Oval shaped with lots of
folding inside
– Inner folds called cristae
• Function
– Supply energy via aerobic
cellular respiration
– Sugars broken down into
water and CO2
– Energy as ATP (adenine
triphosphate0
Mitochondria
• What kinds of cells do
you expect to have
lots of mitochondria?
– Active cells like
muscles, sperm
• They contain their
own DNA
Golgi Apparatus
• Packaging center for the cell
• “Stack of Pancakes”
• Definition
Chloroplast
– Found in plant cells
only and contains the
green pigment
chlorophyll
– PHOTOSYNTHESIS
occurs here
• Appearance
– Large, irregularly
shaped
– Green in color
• Function
– Site of food production
in plants
– Captures sunlight for
photsynthesis
Vacuoles
• Definition
– Large, round sac in
the cytoplasm that
stores water, food,
enzymes etc.
• Appearance
– Plants: 1 large
– Animals: many small
• Function
– Storage tanks
– Fill with water to make
plants plump
Lysosome
• Definition
– Small, round structures
involved in digestive
activities in animal cells
• Appearance
– Round structures
common in animals less
in plants
• Function
– Contain enzymes for
digestion of food to create
energy
– Get rid of dead, dying, or
injured cells/organelles
– Clean-up crew
Centrioles
• In animal cells only
• Function: make spindle apparatus during
cell division
Similarities between plant &
animal cells
• Both contain
– Cell membranes
– Nucleus & nuclear membrane
– Nucleolus
– Mitochondria
– Cytoplasm
– Ribosomes
– Golgi
– SER & RER
Differences between plant &
animal cells
• Plant
–
–
–
–
Chloroplast
Cell wall
One large vacuole
Box shaped
• Animal
–
–
–
–
Lysosomes
Centrioles
Small vacuole(s)
Irregular shape
Venn Diagram Plant vs Aniamal
Practice Identifying Cell
Organelles
• Worksheet
2 Large Groups of Cells
Eukaryote
Cells
and Prokaryotic
Cells
Eukaryotic vs. Prokaryotic Cells
• Membrane bound
nucleus & organelles
• Linear DNA
• Large ribosomes
• No membrane bound
nucleus & organelles
• Circular DNA
• Smaller ribosomes
Flagella
• Function:
– Whip-like structure on some cells that is used
for movement
– Found in both plants & animals
– Human sperm have flagella
Cilia
Function
– Short hairlike projections that produce
movement
• http://www.cellsalive.com/cells/plntcell.htm
– Practice & review structure function of cell
organelles