Date post: | 21-May-2015 |
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Eukaryotic CellsThe Inside Story
Prokaryotic Cells
• No nucleus• No
membrane-covered organelles
• Circular DNA
• Bacteria
Eukaryotic Cells
• Nucleus• Membrane -
covered organelles
• Linear DNA• All other
cells
DNACells
2 Types of Cells
Which is which?
1 of the 3 parts of the Cell Theory states that All cells come from pre-existing cells
So just as large multicellular organisms like humans, dogs, and trees reproduce, your cells do as well
Cells come from..
It turns out that there is a lot more inside a cell than Robert Hooke or Anton von Leeuwenhoek probably would have guessed.
Everything, from the structures covering the cells to the structures inside, perform tasks to help keep the cells alive.
These structures are called organelles.
So What is Inside a Cell?
All cells have outer coverings that separate what’s inside the cell from what is outside.
Cell Membrane Covers all cells, both eukaryotic and
prokaryotic Duties include keeping cytoplasm inside Allow nutrients in and waste products out Also interacts with things outside the cell
Holding It All Together
Cell Wall Only found in plant and bacteria(prokaryotic)
cells
Cell wall in plants is made of cellulose
Provides strength and support to the cell membrane
The strength of billions of cell walls in plants enables a tree to stand tall and its limbs to defy gravity
Holding It All Together
Nucleus Largest and most visible organelle Covered by a membrane Control center of cell Stores the DNA
Nucleolus Dark spot inside the nucleus Stores the materials that will be used later to
make ribosomes in the cytoplasm
The Cell’s Library
Ribosomes Smallest but most abundant organelles
Their job is to hook together amino acids to make proteins
Found in both eukaryotic and prokaryotic cells
Not covered by a membrane
All cells have ribosomes because all cells need protein to live.
Protein Factories
Endoplasmic Reticulum Internal delivery system of a cell Is divided into Smooth and Rough ER based
on appearance and function Rough ER
Ribosomes are attached making it look pebbled
Specializes in protein synthesis Connected to nuclear membrane Proteins synthesized by ribosomes collect in
the ER for transport throughout the cell
The Cell’s Delivery System
Smooth ER Does not have ribosomes attached
Has different functions depending on the cell type
Can be responsible for lipid and hormone synthesis
Breaks down drugs and certain other chemicals that could damage the cell
Difference Between Rough and Smooth ER
Mitochondria Convert the chemical energy stored in food into
ATP which is the molecular fuel that cells use to do work
Inner membrane of mitochondria that has many folds is where most of the ATP is made.
The reason you breathe air is so that mitochondria have the oxygen they need to make ATP
Highly active cells, like those in the liver and heart, may have thousands of mitochondria while other cells may have only a few.
The Cell’s Power Plants
Chloroplasts Additional kind of energy-converting
organelle found in plants and algae Contain flattened, membrane-covered
sacs that look like stacks of coins which contain chlorophyll
Chlorophyll is what makes plants green and also traps the energy in sunlight which plants use to make sugar
The sugar that is produced is used by mitochondria to make ATP
The Cell’s Power Plants
Golgi Apparatus Looks like ER but is located closer to the
cell membrane Receives and modifies lipids and proteins
sent from the ER Final products are then enclosed in a piece
of the Golgi’s membrane that pinches off to form small compartment
Compartment transports contents to other parts of cell or outside the cell
The Cell’s Packaging Center
Vacuoles Very large in plant cells, much smaller in
animal cells Store water and other liquids If full of water they help support the cell
Store the liquids that make roses red and violets blue
Contain the juices you associate with oranges and other fruits
The Cell’s Storage Centers
Vesicles Some form when part of the membrane
pinches off the ER or Golgi
Others are formed when part of the cell membrane surrounds an object outside the cell
The Cell’s Storage Centers
Lysosomes Special vesicles in animal cells that
contain enzymes that digest food particles and wastes
Destroy worn-out or damaged organelles Get rid of waste materials and protect
cell from foreign invaders If lysosome membrane breaks, the
enzymes spill out into the cytoplasm which kills the cell
Packages of Destruction
Plant or Animal?
Plant or Animal?
You are going to create a drawing of a eukaryotic cell.
However, instead of making it a realistic cell, your cell should be made of drawings of objects that represent the organelle’s job.
For example, the Golgi Apparatus, which transports materials, could be a bus or a car.
Homework