Eukaryotic cell structure

The Cell factory Organelles

Highly specialized structures within the cell Little organs

2 major divisions of the eukaryotic cell Nucleus

The “brain” DNA

Cytoplasm Portion outside the nucleus but inside the cell membrane

2 types of Eukaryotic cells Plant cells

Animal cells What are the differences? (write them down!!!)

Nucleus

Brain of the cell Office of the factory Contains nearly all the cell’s DNA and

with it the coded instructions for making PROTEINS and other important molecules

Nuclear envelope Surrounds nucleus Made of 2 membranes Dotted with thousands of nuclear pores

How do we get messages, instructions and blueprints out of the office?

Allow material to move in and out of nucleus by using “little runners” such as proteins, RNA and other molecules

Inside the nucleus we see…

Contain a granular material called… CHROMATIN

Chromatin= DNA + protein Usually spread out in nucleus During cell division, chromatin clumps

together or condenses…we call this…. CHROMOSOMES

Chromosomes

Threadlike structures that contain genetic information that is passed on from one generation to the next

Nucleolus

Small dense region inside the nucleus Function: assembly of ribosomes begin…

Ribosomes Most important function of cell is…

Making proteins Proteins regulate a zillion different things Like…

Proteins are assembled ON Ribosomes Ribosomes are small particles of protein &

RNA (what’s RNA?) They follow instructions from the nucleus to

make proteins…follow the orders from the “head haunchos” in the main office

Scattered throughout the cell They are like little factories If a cell’s main function is making proteins, how

many ribosomes are you going to have?

Endoplasmic reticulum (ER)

Internal membrane system The site where the lipid components of

the cell membrane are assembled, along with proteins and other materials exported from the cell

2 types Smooth ER Rough ER

Rough ER Involved in protein making (synthesis) So what are we going to see on it?

ribosomes Once a protein is made, it leaves the

ribosome and goes into the Rough ER The rough ER then modifies the protein All proteins that are exported by the cell

are made on the RER Membrane proteins are made on the

RER too

Smooth ER NO ribosomes on it Looks smooth Contains collections of ENZYMES that have

specialized tasks What do enzymes do?

Tasks include: Synthesis of membrane lipids Detoxification of drugs Liver cells

Big in detox therefore….what do u think liver cells have a lot of?

Golgi Apparatus Discovered by Italian scientist Camillo Golgi Once proteins are done being “modified” in the

RER, they move onto the Golgi apparatus Looks like a stack of pancakes Function: modify, sort, and package proteins

and other materials from the ER for STORAGE or SECRETION outside the cell Proteins are “shipped” to final destination

They are the CUSTOMIZATION SHOP Finishing touches on proteins before they leave

factory

Lysosomes (Lie-so-soh-mz) The factory’s clean-up crew It’s an Organelle filled with

enzymes Function: Digestion (break

down) of lipids, carbohydrates, and proteins into smaller molecules that can be used by the cell

Also digest organelles that have outlived their usefulness

What do you think happens if lysosomes malfunction?

A bunch of “junk” build up in the cell Is this good? Many human diseases result from

malfunction of lysosome Tay-Sachs disease

Vacuoles The factory’s storage place Only in certain cells Sac-like organelles Function: stores material such as water,

salts, proteins, and carbohydrates Plant cells have a single, large central

vacuole Pressure of central vacuole allows plants to

support heavy structures

Single-celled organisms and some animals also have vacuoles…

Paramecium Contractile vacuole Contracts rhythmically to pump excess water

out…this maintains what? homeostasis

What is the one thing all living things need to eat, breath, reproduce, move and much more?

ENERGY!!!!

Two ways cells get energy…

From food molecules From the sun

Mithochondria

Convert chemical energy stored in food into compounds that are more convienent for the cell to use

Has 2 membranes Inner membrane Outer membrane

Nearly all come from the ovum You get your mitochondria from your mom!

Chloroplasts

Capture energy from the sunlight and convert it into chemical energy…what is this process called? PHOTOSYNTHESIS

Like solar power for plants 2 membranes Inside: large stacks of other membranes

that contain chlorphyll

Organelle DNA

Chloroplasts and mitochondria contain their own genetic info In form of small DNA

molecules

Lynn Margulis

American biologist Chloroplasts and

mitochondria are descendents of prokaryotes

She said… Ancient Prokaryotes from wayyyyy back in the

day had a symbiotic relationship with the ancient eukaryotes What is symbiotic? (review ecology!!!)

The prokaryotes lived inside the eukaryotes There were prokaryotes that used oxygen to

make energy (ATP) Mitochondria

There were prokaryotes that used photosynthesis to get energy Chloroplasts

Endosymbiotic Theory

Idea that mitochondria and chloroplasts evolved from prokaryotes

Cytoskeleton

Supporting structure and transportation system Network of protein filaments that helps

the cell to maintain its shape and to help the cell move

2 main type of filaments Microtubules Microfilaments

Microfilaments

Threadlike structures Made of protein called ACTIN Extensive networks Tough, flexible framework Help cells move Assembly and disassembly helps cells

move (like amoebas)

Microtubules

Hollow structures Made of proteins called TUBULINS Maintain cell’s shape Important in cell division

Make mitotic spindle (separates chromosomes)

Help build projections from cell surface…

Cilia and Flagella

Plural: cilium and flagellum Enable cells to swim rapidly through liquid Like oars of a boat

Centrioles

Only animal cells Made of protein

TUBULIN What else is made of

tubulin?

Near nucleus Help organize cell

division

Antwon van Leeuwenhook Robert Hook Cell Theory Electron microscope Prokaryote Eukaryote Organelles Cytoplasm Nuclear envelope Chromatin Nucleus Ribosome Smooth Endoplasmic reticulum Rough endoplasmic reticulum Course adjustment knob Fine adjustment knob Proteins DNA Contractile vacuole Central Vacuole

Golgi apparatus Lysosome Vacuole Mitochondrian Chloroplast Cytoskeleton Centriole Mictrotubule Microfilament Theodor Schwann Matthias Schleiden Rudolph Virchow Lynn Margulis Endosymbiotic Theory Cilia Flagella Photosynthesis Tay-Sachs disease