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, one-celled 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.

1665

2) ‘animalcules’1) Improved lens 1674

1676

16833) Discovered bacteria

Plants made of cells1838

Animals made of cells

Cells come from cells1855

1839

PRO – NO - Prokaryotic

EU – TRUE - Eukaryotic

NONO Nucleus

EUEU it’s truetrue they DODO 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

EukaryotesThese 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

review!

Nucleus

Nuclear Pores

Nuclear Envelope

ER

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

http://www.sumanasinc.com/webcontent/animations/content/vesiclebudding.html

http://bcs.whfreeman.com/thelifewire/content/chp04/0402002.html

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 respirationC6H12O6 + 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 • 6 CO2 + 6 H2O + energy (from sunlight) C6H12O6 + 6 O2

Key process: Photosynthesis

Glucose

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.

Cytoskeleton• Cell Framework• A network of protein filaments

that helps the cell to maintain its shape

Process = support

Vacuoles• Storage Facility• 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”

http://www.susanahalpine.com/anim/Life/memb.htm

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

Process = Support And protection

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

                                                                                                                                                                            

                        

Animal Cells Plant Cells

Compare an Animal and Plant cell using the following:Cell membrane, Nucleus, ER, Mitochondria, Centrioles, Vacuoles, Golgi body, Plastids, Ribosomes, Cell wall, Lysosome

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