Cell Theory & The Scientists Involved Robert Hooke

Cell Theory&

The Scientists Involved

Robert Hooke

Cork oak (Quercus suber)

Anton Van Leeuwenhock

• Date: 1600’s• Theory: saw living organisms in pond

water never seen before (animalcules).• Occupation: invented the simple

microscope (single lens)

Cell Theory

• Cells are the structural units of all living things.(Cells carry on their own life functions)

• New cells can only arise from other cells by the process of cell division

• Viruses are not made up of cells.

• Also viruses do not carry out there own life functions.

• Where did the first cells come from?

• Mitochondria and chloroplasts contain their own DNA.

• Slime molds are multinucleated.

I’m the Herpes Virus

We’re Influenza Viruses!

• Slime molds do not have cells as a basic unit. They have an unorganized cytoplasm and many nuclei, they also do not have a distinct cell shape

Organelle• A specialized structure

in the cytoplasm of a cell that carries out a specific function.

Nucleus• Located in the center

of a cell, the nucleus is a large, dense, membrane-enclosed body that controls the cell’s metabolism and reproduction.

Nucleolus• Site of RNA

(ribonucleic acid) production

• A dense, granular body found in the nucleus

Cell membranes are semi-permeable. This means that the cell membrane only allows certain substances to pass through it. (Phospholipid bilayer)

Large structure comprised of smaller subunits.

According to the Fluid Mosaic Model the cell membrane Is a two layered structure composed of lipids and proteins.And is what we currently believe the cell membrane is composedof.

A hairlike organelle on the surface of a cell

with the capacity for movement

Green arrows point to Cilia

Flagella

• Involved in cell movement

• Only a few on the cell surface

• Whip-like tail• 9 microtubule doublets

arranged in pairs• 2 microtubules in

center

Phagocytosis• The process in which

large particles or small organisms are ingested into a cell.

PinocytosisThe process in which

liquids or very small particles are taken into a cell.

The substance is in contact with the surface of the cell membrane, the membrane pinches and forms a pouch.

Cytoplasm

• A watery material located between the cell membrane and the nucleus.

• Holds the organelles

Endoplasmic Reticulum

• A system of fluid filled canals or channels enclosed by membranes

• Serve as a path of transport throughout the cell

• Rough endoplasmic reticulum are lined by ribosomes.

Ribosome• An organelle that is

the site of protein synthesis in a cell.

• They are produced by the nucleolus.

Golgi Body

• Serve as packaging and storing centers for the secretory products of the cell

Lysosome

• Small, saclike structures surrounded by a single membrane

• Involved in the digestion of food within the food vacuoles of the cell

• Found in white blood cells, in multicellular organisms

MitochondrionThe powerhouse of the cell.

An oval, membrane enclosed organelle, in which most of the reactions of cellular respiration occur.

Mitochondrion

MicrofilamentA solid, thread-like organelle that can function as a supporting structure or aid in cell movement.

Act as “cross-bracing” in the cell.

Microtubules

• A long, cylindrical organelle found in cilia and flagella

• Are also involved in the movement of the chromosomes during cell division

• Composed of a protein called tubulin

Vacuole• A fluid-filled

organelle enclosed by a membrane.

• Stores waste and food.

• Occupies most of the space in the cytoplasm.

Specialized vacuoles include…Contractile Vacuole

• Extra water in the cell collects here and is expelled from the vacuole directly into the environment

• Works kind of like a water pump

Centrioles –found only in animal cells, these organelles aid in cell division.

In addition to the organelles previously mentioned, plants

also have additional organelles-

Contain a cell wall

Have chloroplasts

Chloroplasts• A membrane-enclosed

organelle found in the cells of some protists and almost all plants.

• They capture the sun’s energy and convert it into chemical energy during the process of photosynthesis.

SimilaritiesSimilarities ––

Plant and Animal Cells Both Plant and Animal Cells Both Have:Have:

A proper nucleus Cytoplasm

A cell membrane Chromosomes Mitochondria

Animals

Do not contain a cell wallDo not contain chloroplastsHave small vacuolesGenerally have spherical shape.Contain centrioles