Looking Inside Cells

Enter the Cell  Key Concept: A cell wall is a stiff layer that helps to protect and support a plant cell.  Animal cells do NOT have cell walls.  Many materials like oxygen and water can pass through the cell wall.

Organelles in the Cytoplasm  Key Concept: In the cytoplasm there are many organelles that have a specific function.  Animals CellPlant Cell

CYTOPLASM  Cytoplasm - gel-like fluid  Jell-o, hair gel  Can you think of others?

 Key Concept: The cell membrane controls what substances go into and out of a cell.  For a cell to live, the cell membrane must let material pass in and out of the cell.

CELL WALL VS. CELL MEMBRANE  The cell wall is only found in the plant  The cell membrane is found in the cell wall and the cell membrane  Cell wall is like a wall of a house it is strong! The cell wall is made of CELLULOSE….REMEMBER THAT!  The cell membrane is like a screen: it allows some materials in and keeps others out.

Sail on to the Nucleus  Key Concept: The nucleus is the control center of the cell and directs all of the cell’s activities.  The nucleus is protected by a membrane called the nuclear envelope.  The nucleus holds genetic information. Genetic information controls what the cell does.

WHERE IS THE NUCLEUS?

What is the genetic information?  The genetic information inside the nucleus is called DNA (deoxyribonucleic acid)

Nuclear Envelope  Why do you think DNA has to be protected by the nuclear envelope?

Nuclear Envelope  The nuclear envelope has holes called pores that allows necessary molecules to pass between the nucleus and the cytoplasm

ENDOPLSAMIC RETICULUM  Endoplasmic Reticulum - Interconnected network of thin folded membranes that form a maze. It aids in the important production of proteins and lipids (necessary fats)

RIBOSOMES  Ribosomes - protein factory  Factory – they link together amino acids, which in turn make up proteins  Why are proteins important?

GOLGI Apparatus  Golgi apparatus- process, sort, and deliver the proteins to where they need to go.  Post Office, UPS

GOLGI Apparatus  Golgi apparatus-  Some proteins are stored for later use  Some are transported to other organelles within the cell  Some are carried to the membrane  Some are carried outside the cell

Vesicles  Vesicles – Isolate and transport molecules  Vesicles are small sacks that divide materials from the rest of the cytoplasm and take things from place to place  Cells sometimes need to isolate (separate) different chemicals until they are ready to be used

Proteins Made ER makes a vesicle around the protein Protein transported to Golgi App. Golgi makes modifications Put into a new vesicle Held, Transp., or Secreted

MITOCHONDRIA/MITOCHONDRION  Mitochondria - power house  It supplies energy to the cell  Battery, solar panel  Can you think of others?

MITOCHONDRIA/MITOCHONDRION  Mitochondria - Also has its own separate DNA and their own ribosomes

VACUOLES  Vacuoles - Fluid filled sac used for storage by the cell.  Plant cell: one large vacuole. Like a swimming pool  Animal cell: many small ones like cupboards.

LYSOSOMES  Lysosomes - rids the cell of waste. (Like a garbage disposal.)  They contain enzymes and defend the cell from invading bacteria and viruses.  Lysosomes are mostly found in animal cells  Lysosomes also recyle foreign or worn out parts

Centrioles  Cylinder shaped organelles made of short microtubules arranged in a circle  Appear to help DNA divide during cell division

Plant cells… Cell Walls and CHLOROPLASTS  Chloroplasts - capture sunlight for energy to make food. (only in PLANTS)  Like a solar panel  Chloroplasts convert solar energy into chemical energy through photosynthesis  The outer cell wall supports, and gives protection to the cell

Chloroplasts  Chloroplasts also have pigment (color)  Only the chloroplasts that have chlorophyll can carry out photosynthesis  The rate of photosynthesis increases as the number of chloroplasts with chlorophyll increases  That means: it happens faster

Cell Diversity  Key Concept: The variety of structure in cells reflects differences in cell function.  Cells come in many shapes. The different shapes help them to do different jobs.  Some cells have organelles that others do not. Give me examples and write them down.