Download CELLS & the ORGANELLES

CELLS & the
ORGANELLES
Prokaryote vs. Eukaryote
Animal vs. Plant
Cells
“Life is Organized”
Smallest / most simple
Atoms
C,H,N,O,P,S
Molecules
Organelles
Cells
Tissues
Organs
Organ Systems
Organism
Species
Population
Community
Ecosystem
Biome
Ex: Tundra, desert,
temperate forest
Biosphere
Largest / most complex
Early Microscopes
• Robert Hooke (1665)
 Coined the term “cell” (Why?)
 looking at cork, he saw little boxes
 Is cork alive?
• Anton von Leeuwenhoek (1674)
 saw living cells in pond water
Cells
Cell Discoveries
• Matthias Schleiden (1838)
 Plants are made of cells
• Theodor Schwann (1839)
Animals are made of cells
• Rudolf Virchow (1855)
 Saw dividing cells
 new living cells come from
pre-existingCellscells
The Cell Theory
1. All living things made of cells.
2. Cell are the basic unit of structure &
function for life.
3. Cells can only arise from pre-existing
living cells
Cells
Types of Organisms
• Unicellular organisms  living organisms
that are composed of only ONE cell
– Examples: bacteria, algae, protists, yeast
• Multicellular organisms  any organism
that is made of MORE THAN ONE cell
– Evolved later
Cells
Prokaryote vs. Eukaryote
• Prokaryotic Cells
– DNA not bound by a
membrane… no “true
nucleus”
– Usually smaller, simple
• Nearly all unicellular
– No membrane bound parts
(organelles)
• Ex: bacteria
– Read Section 6.3
• Eukaryotic Cells
– DNA is bound by a
membrane bound
nucleus
– Larger, complex, has
internal organization
– Have internal membrane
bound structures =
organelles
• Ex: you, plants, algae
https://www.youtube.com/watch?v=WRO-DPyB9Bk
Cells
Basic Structures For ALL Cells
• Cell membrane
– Surround the cell –
barrier between inside
and environment
• Cytoplasm
– Contains water and
organelles
• DNA
– Instructions for the
cell to carry out
• Ribosomes
– Makes proteins
Cells
Organelles
•
Very small size
•
Have specific functions
Create specificity of cells
–
•
EX: muscle cells have more mitochondria than skin cells
•
Found throughout cytoplasm
•
Examples:
–
Nucleus, ribosomes, endoplasmic reticulum, Golgi apparatus,
lysosomes, mitochondria, chloroplasts (plants only), vacuoles,
cytoskeleton, centrioles (Animal only)
Cells
Cells
Cells
The Nucleus:
Control center of the cell, houses genetic material
Cells
Nucleolus
• Is a small
dense region in
the nucleus
• Makes
ribosomes,
which make
proteins
Cells
RIBOSOMES
• Free floating in
cytoplasm
or
• Attached to ER
• “reads” RNA code
from DNA to
assemble proteins
• “protein factory”
Cells
ENDOPLASMIC RETICULUM
• Internal passageway
within the cell
• Can be “Rough” or
Smooth
– Rough has ribosomes
attached  protein
synthesis
– Smooth has no
ribosomes  membrane
lipid synthesis,
detoxification, cholesterol
metabolism
Cells
GOLGI APPARATUS
• Modifies, sorts,
packages proteins
coming from ER
• Destination of
products
– storage in cell
– export out of cell
• Customizes
– Adds lipids, carbs to
proteins
Cells
LYSOSOMES
• Small, enzyme-filled organelles
• Digests material for use or disposal
– Only common in animals but recent evidence suggest
they are in plants as well
Cells
MITOCHONDRIA
• Convert food into
usable energy
• Have an outer & inner
membrane
• Has its own DNA!
– Inherited from your
mom
Cells
CHLOROPLASTS
• Capture sunlight &
convert it to energy
– Photosynthesis – make
their own food
– Green plants and some
algae
• Have 2 membranes
• Contain the green
pigment chlorophyll
• Has its own DNA!
Cells
VACUOLES
• Stores materials
• Water, salts, protein,
carbs
• Largest in plants
– Gives turgor pressure
• Larger in plants
Cells
CYTOSKELETON
• Structural support
& transport
MICROFILAMENTS
Actin – threadlike
protein
MICROTUBULES
Tubulins – protein
basis of cilia & flagellaCells
CENTRIOLES
• Help in the process of
cell division
• Only in Animals
Cells
PLANTS V. ANIMALS
• CELL WALLS made • CENTRIOLES
of cellulose
• Smaller or No vacuoles
• LARGER VACUOLE
• CHLOROPLASTS
Cells
Colonies
Colonies – a group of unicellular microorganisms living together
If colony attaches to a solid surface = biofilm
Volvox
Chlamydomonas
VS
• Volvox is a colony of individual cells.
• Each cell of a Volvox resembles a
Chlamydomonas (a one-celled organism).
•Volvox cells coordinate the beating of
their flagella so that the movement is not
random through water.
- shows cooperation among cells Cells
Colonies of Bacteria
Cells
Cell to Cell Connections
• Cells in same tissue communicate with each
other through junctions
– Tight junction : membranes are fused, stitched
together; no passage
– Desmosomes: protein fibers that anchor in
cytoplasm of neighboring cells
• – allow passage of materials
– Gap junction : Channels formed by donut-shaped
proteins btwn cells ; yes passage
– Pits & Plasmodesmata : (plants) cell walls
perforated with pits, strands of cytoplasm
(plasmodesmata) run through pits connecting cells
Cells
Cells
Cell to Cell Connections
Cells
Extracellular Matrix
• Solution of macromolecules
(proteins & carbs) that
surround cells in a tissue
– Secreted by the cell itself
to the space outside
• Holds cells together
• Allows them to migrate &
interact
• May regulate behavior in
cells
– Ex: collagen
Cells
Division of Labor In
Multicellular
Organisms
Cells
Tissues – a group of cells working together
Organs – a group of tissues working together
Organ System – a group of organs working together
Organism – a group of organ systems working together
Differentiation – when cells take on a specific role
Cells