Transcript What the Cell? - Effingham County Schools

Cells! Who wants some?!
Not that type, but this
kind…
A cell is the basic unit of life
But first, a brief history of the cell…
Robert Hooke, an Englishman, was looking at cork through a basic microscope
and saw tiny chambers which he called “cells”. This occurred in 1665.
Close to the same time, a Dutch tradesman,
named van Leeuwenhoek (LEE-van-hook)
used a microscope to observe living, onecelled creatures in drinking water. Yum. He
called them “animalcules”.
More observations…
• Finally in the 1800’s, after the scientific community observed
and recorded cell activities, they concluded this-The Cell
Theory:
1) Living things are composed of cells.
2) Cells are the basic units of structure
and function of living things.
3) Cells come from other cells
Cell Theory and Discovery
• Cell Discovery
• Many scientists contributed to the discovery of
cells and the cell theory.
Cells … cork
Looked like rooms
in a monastery.
1) Improved lens
2) ‘animalcules’
3) Discovered bacteria
1665
1674
1676
1683
Plants made of cells
Animals made of cells
1838
1839
1855
Cells come from cells
PRO – NO Prokaryotic
NO Nucleus
EU – TRUE Eukaryotic
EU it’s true they
DO have a
nucleus
Prokaryotes
These fellahs, despite their simplicity, carryout activities like any other living
creature; in fact, they grow, reproduce, respond to their environment and
can move. They are older and smaller than Eukaryotes.
The Prokaryotes
• Generally smaller and simpler than eukaryotes
• Key: have genetic material that is not contained
in the nucleus
• Less “complicated” than eukaryotes but still
carry out all aspects of “life”
• Do not have membrane-bound organelles such
as mitochondria, ER, Golgi-bodies, etc.
• Bacteria are prokaryotes
Some Prokaryotic Examples
Eukaryotes
These contain internal
structures wrapped in
a membrane. Think:
tiny organs, or,
organelles.
Some eukaryotes live as single-celled organisms; others form large,
multicellular organisms like plants, animals, fungi, and protists.
My Friends the Eukaryotes
• You are made of Eukaryotic cells!!!
• Usually contain dozens of structures and
internal membranes
• Key: Contain a nucleus in which genetic
material is separated from the rest of the
cell
• Can be highly specialized
• Much larger and more complex than
prokaryotes
• Can be single celled or multicellular:
humans, hamsters, venus fly traps, etc.
Some of our Eukaryotic friends
Cell Types
What is an organelle
• Membrane bound structure that has a
specific function or job to do in
eukaryotic cells
• They’re not in Prokaryotes! (bacteria)
• Plant cells have an organelle that
animals don’t
• Animals have one organelle plants don’t.
Plant vs Animal
VS
Plant Cell
Animal Cell
Nucleus
• Control Center
• Contains nearly all DNA – instructions for making
proteins and other important molecules
• Surrounded by nuclear envelope/membrane
– Dotted with nuclear pores = stuff in and out
• Key processes:
Controls metabolism of cell, control
Cell division, proteinsynthesis
Chromosome
• (The Data) … all the directions
• (DNA)
Nucleolus
• Nucleolus – small dense region inside nucleus.
Ribosomes are made here.
Endoplasmic Reticulum
• Transportation
• Rough Endoplasmic
Reticulum (RER)
– Covered in ribosomes (rough)
– Makes and transports proteins,
especially membrane proteins
• Smooth Endoplasmic
Reticulum (SER)
– Synthesis (make) of membrane
lipids
– Contain enzymes that can
detoxification of drugs – Liver
has lots of SER’s
Notice how the E.R. is
attached to the nucleus
…. Like the ‘hallways’
Smooth and Rough ER
Key process: Transportation of molecules
Ribosomes!
• Protein Factory
• Proteins are assembled on these organelles by
following coded instructions from the nucleus
Key process: Proteinsynthesis
Nuclear
Pores
review!
Nuclear
Envelope
ER
Nucleus
Ribosomes
Golgi Apparatus
• Packaging Center
• Modify, sort, and package proteins and other
materials from the endoplasmic reticulum for
storage or secretion.
Key processes: Packaging and sorting of proteins
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Mitochondria
• Power House
• Convert chemical energy stored in food to a
form a cell can use (ATP) during the process of
cellular respiration.
• Contain own ‘Mitochondrial DNA’
• Has double membrane
Key process: Cellular respiration
C6H12O6 + O2
H2O +CO2 + ATP
Chloroplast
• Food Factory
• Only in plants – Contains chlorophyll
• Captures energy from the sun and converts it into chemical
energy by a process called photosynthesis
Glucose
• 6 CO2 + 6 H2O + energy (from sunlight)  C6H12O6 + 6 O2
Key process: Photosynthesis
Plastids - Chloroplasts,
Chromoplasts and Leucoplasts
• Chromoplasts
contain carotenoids that
give flowers, fruit and autumn leaves
their orange, yellow and red colors.
•Leucoplasts store starch and other
molecules for the cell. Many in potato
cells.
Process - Storage
Mitochondria/Chloroplasts
• These two utilize energy from food and the sun
respectively and convert it into energy the cell can
use.
Process = support
Cytoskeleton
• Cell Framework
• A network of protein filaments
that helps the cell to maintain its
shape
• Storage Facility
Vacuoles
• Plants have big vacuoles, animal cells many small vacuoles.
• Store materials like water, salts, proteins, and
carbohydrates
• In plants, there is a large vacuole which helps with
maintaining pressure (turgor pressure)
– Allows plant to support heavy
loads like leaves and branches
Lysosome
• Waste Management
• In animal cells ONLY
• Have enzymes used to break down lipids,
carbohydrates, and proteins
• breaking down old organelles – even old cells can be
broken down in a process called autolysis.
• Sometimes called suicide sacs.
Process - Digestion
Cell boundaries aka cell membrane
• Cell membrane regulates what enters/leaves the cell.
Process - Osmosis
2 Layers of phosholipids studded with
proteins = “fluid mosaic model”
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Process = Support
And protection
•
•
•
•
Cell Wall
Castle Wall
Only in Plant Cells
Provides support an protection for cell
Mostly made of cellulose
– Cellulose is the key component of wood and paper
Centrioles
Only in animal cells.
Plays a role during cell division.
Assist in the making of cilia and flagella.
Process – Cell division
Come on baby let’s do the
locomotion……
• Cilia
• Flagella
Plant Cell
Animal Cell
Journal
Compare an Animal and Plant cell using the following:
Cell membrane, Nucleus, ER, Mitochondria, Centrioles, Vacuoles, Golgi body,
Plastids, Ribosomes, Cell wall, Lysosome
Animal Cells
Plant Cells