Download Cell Organelles - Mrs. Gallegos Website

Cells
Chapter 7
How many cells do humans have?
About 10 TRILLION cells!
If you tried counting them at a rate of
1cell/sec, it would take over 2000 years to
do it.
Discovery of Cells
Robert Hooke (1665)
Used microscope to look at thin slice of
cork tree
Named structures “cells” like the small
rooms monks lived in.
Anton van Leeuwenhoek
1673- Used a simple microscope to
observe pond scum & discovered living
single-celled organisms
He called them “animalcules”
1838- Matthias Schleiden- all plant parts are made
of cells
1839- Theodor Schwann- all animal tissues are
composed of cells.
Development of Cell Theory
1858- Rudolf Virchow, concluded that cells must
arise from preexisting cells.
The Cell Theory
1. All living things are composed of one or more
cells.
2. The cell is the basic unit of structure and function
in all living things.
3. All cells are produced from pre-existing cells.
Sizes of Living Things
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
0.1 nm
1 nm
10 nm
100 nm
protein
amino
acid
1
m
10
m
100
m 1 mm
1 cm
0.1 m
chloroplast
plant and
animal
cells
100 m 1 km
rose
mouse
frog egg
1 m 10 m
virus
most bacteria
human egg
atom
ant
ostrich
egg
blue whale
human
electron microscope
light microscope
human eye
8
Types of Microscopes
1. Compound light
microscope


Light passes
through lenses to
magnify image up
to 1000X
Can observe
living cells 
Types of Microscopes
2. Electron
microscope


Uses a beam of
electrons to
magnify image
> 1000X
Kills cells being
observed 
Scanning Electron Microscope
Produces 3-dimensional images of cell
surface
Transmission Electron Microscope
Electrons pass through only thin samples
Explores cell internal structures and large
proteins
Prokaryotes and Eukaryotes
Prokaryotes
Prokaryotes: (pro- means before, and
karyote means nucleus);first type of cells to
evolve




Very small, the size of mitochondria
Unicellular
Kingdoms: Archaea and Bacteria
Reproduce asexually via Binary Fission
Prokaryotes
Structures:
cell membrane
cell wall
ribosomes
flagella or cilia
nucleoid
cytoplasm
capsule
No membrane bound
organelles - only eukaryotes
have
A day in the life of Bacteria
Can only move in two directions forward
(swimming) and tumbling, and at one speed.
Divide every 20 minutes
Long family history….. 3.5 billion years ago to be
exact (The earth formed 4.6 billion years ago)
From Prokaryotes to
Eukaryotes
EUKARYOTES
Emerged 1.6-2.1 Billion years ago
Kingdoms: Animals, Plants, Fungi, and Protists
Characteristics:

Complex structure with Nucleus and Membrane-Bound
Organelles
Unicellular and Multicellular
If all cells originate from other
cells, how do you think
eukaryotes came about?
Endosymbiosis

Endosymbiotic theory states that some
eukaryotic organelles
evolved from
prokaryotes.
The host and prokaryotic
cells benefited from
each other and
eventually resulted in
this evolutionary change
of eukaryote cells.
Plant and Animal Cells
• Plant Cell




Cell Wall
Chloroplasts
Rigid Shape (Cell Wall)
Large Central Vacuole
•Animal Cell
•No Cell Wall
•Irregular/ round shape
Plant and Animal Cell Structures:
Nucleus, Nucleolus, Nuclear Envelope
Nucleus - stores
genetic information
Nucleolus ribosome production
Nuclear envelope protective layer
controlling what
enters and leaves
Plant and Animal Cell Structures:
Cytoplasm and Cytosol
Cytoplasm – everything
inside cell membrane
Cytosol - gel like material
within the cell, includes
proteins, dissolved molecules,
water, etc.
Cell Membrane
Phospholipid bilayer
Flexibile
Regulates what goes
in and out of cell
Cell Wall
Located outside
membrane in plant
and prokaryotic cells,
NOT in animal cells.
Rigid, porous
Plant and Animal Cell Structures:
Ribosomes
Also found in Prokaryotes
Protein synthesis (makes proteins)
Plant and Animal Cell Structures:
Cytoskeleton
Microfilaments:
carry out cellular movements including
gliding, contraction, and cytokinesis.
Microtubules:
•
•
Cell shape
Helps move things within the cell (tracks)
Form the spindle fibers for separating
chromosomes during mitosis
Plant and Animal Cell
Structures: Flagella and Cilia
Hairlike structures that aid
in movement (motility) of
the cell
ORGANELLES
Endoplasmic Reticulum
Structure: network of interconnected
membranes forming channels within cell
Smooth Endoplasmic
Reticulum (SER)
Rough Endoplasmic
Reticulum (RER)

Covered with ribosomes which
synthesize protein

A site for synthesis and
metabolism of lipids (fats).
ribosomes
rough
endoplasmic
reticulum
smooth
endoplasmic
reticulum
Golgi Apparatus
Purpose: Process, Package, Secrete
Structure

a series of stacked membranes
transport
vesicle
Function

Modifies and packages
macromolecules for transport
elsewhere in the cell in vesicles
transport
vesicle
ER
Nucleus
Golgi apparatus
Mitochondria
Purpose: Energy Production
Structure:
• Double membrane with a series of
folds called cristae.
Function:
• Cellular respiration- chemical energy
from food converted into usable energy
for cell
• Contains its own DNA
“Powerhouse of the cell”
Lysosomes (Animals Mostly)
Garbage disposal
of the cell
Contain digestive
enzymes that
break down lipids,
carbohydrates,
proteins, invaders
and wastes
Animal Cells Only:
Centrioles
Organelles used in cell
reproduction
Produce microtubules
Plants Mostly: Vacuole
Membrane surrounded
"bags" that contain
water, enzymes and
storage materials in
plants.
smaller vacuoles in
animal cells
Plants Only: Chloroplasts
Photosynthesis: capture
light energy to produce
sugars
Double outer membrane
Human Cell Types
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Endomembrane System: A Visual Summary
secretion
incoming vesicle
brings substances into the
cell that are digested when
the vesicle fuses with a
lysosome
lysosome
contains digestive enzymes
that break down worn-out
cell parts or substances
entering the cell at the
secretory vesicle
fuses with the plasma
membrane as secretion
occurs
Golgi apparatus
modifies lipids and proteins
from the ER; sorts them
and packages them in
vesicles
plasma membrane
transport vesicle
shuttles proteins to
various locations such as
the Golgi apparatus
transport vesicle
shuttles lipids to various
locations such as the
Golgi apparatus
lipid
smooth endoplasmic
reticulum
synthesizes lipids and
also performs various
other functions
RER synthesizes proteins and
packages them in vesicles;
vesicles commonly go to
the Golgi apparatus
ribosome
40
Fluid Mosaic Model
Proteins, carbohydrates are floating among
the lipid bilayer
Allows SOME things to enter/exit cell
(selectively permeable)
Quick Review
Which organelle is the control center of the cell?
Nucleus
Which organelle holds the cell together?
Cell membrane
Which organelles are not found in animal cells?
Cell wall, central vacuole, chloroplasts
Which organelle helps plant cells make food?
Chloroplasts
What does E.R. stand for?
Endoplasmic reticulum