The Structure and Function of Cells Cell Theory Parts of a cell Organelles Cell Diversity Crossing the Membrane Unit 5

The Cell Theory 4 Parts –Cells are the basic unit of life –All organisms are made up of one or more cells –All cells carry out life processes –All cells arise from pre-existing cells

Who is Responsible for this cell theory???? A whole bunch of dead scientists….. –Anton Von Leeuwenhoek –Robert Hooke –Matthais Schleiden –Theodor Schwann –Carolis Linnaeus

The Parts of a Cell (organelles) Organelle = Little organs

Cell membrane Found in plant and animal cells Outside of cell Controls what enters and leaves the cell. Holds the cell together and keeps the organelles inside.

Cell Wall (Plant cell only) Cell Wall

Cell wall - What is it? Found only in plant cells outside of the cell membrane Composed mainly of cellulose (type of carbohydrate)

What is the Cell Wall for? Helps to maintain the shape of the plant and keep the structure of the plant.

The Nucleus Brain of the cell It tells every part of the cell what to do. Prokaryotes-do not have a nucleus Eukaryotes-have a nucleus

What’s inside the nucleus? DNA (deoxyribonucleic acid) DNA tells the cell what proteins to make and what the cell needs to do.

The Nuclear Membrane The nuclear membrane is a membrane around the nucleus that holds it together and helps keep DNA inside

Nucleolus Looks like a small, dark area inside the nucleus. This contains protein and RNA…

Ribosomes Protein builders of the cell Found either free floating in the cytoplasm (fluid that fills a cell) or attached to the endoplasmic reticulum. Proteins made are used inside and outside of the cell for growth and repair.

Endoplasmic Reticulum (ER) 2 Types - Rough and Smooth ER Used for transport in the cell

No Ribosomes on its surface Has Ribosomes on its surface

Golgi Apparatus Made out of a bunch of flattened sacs. Think of a stack of pancakes. It is the packaging center of the cell. Like a mailroom It takes simple molecules and combines them to form more complex molecules.

Mitochondria POWERHOUSE OF THE CELL Where cells use glucose to make energy (ATP) Site of respiration in a cell

Chloroplast (Plant cells only) Carry out photosynthesis - take energy from the sun and make food. This food comes in the form of sugars and starches (glucose)

Photosynthesis

Vacuole Storage compartments in cells Some contain food, others hold oil, some hold wastes They are huge in plant cells and much smaller in animal cells The vacuole basically holds things that the cell might need, like a backpack

Lysosomes Have enzymes that break down waste and unwanted cellular material.

Centrioles Only in animal cells Where chromosomes attach during cellular reproduction.

Lets put ‘em all together Animal CellsPlant Cells

Animal Cell Golgi Apparatus Lysosome Mitochondria Vacuole Endoplasmic Reticulum Nucleus Nucleolus Flagella Cell Membrane

Animal Cells-Drawing

Plant Cells Where do they come from? Plants of course……DUH!! All plant cells have the same characteristics

Plant cell Endoplasmic Reticulum Chloroplast Cell membrane Cell wall Vacuole Mitochondria Golgi Nucleus

Major Differences between Plant and Animal Cells Plant Cells Plants have a cell wall Contain chloroplasts Have a large vacuole Do NOT have centrioles Animal Cells No cell wall No Chloroplasts Small vacuoles Have centrioles

One more thing to worry about… Prokaryotic vs. Eukaryotic cells Prokaryotes NO NUCLEUS Have a cell membrane and cytoplasm…but no organelles Carry out life processes EXP: Bacteria Eukaryotes HAVE NUCLEUS Have organelles contained within the cytoplasm Carry out life processes EXP: Plant and animal cells