Cell Notes

Early Contributions Robert Hooke - The first person to see cells, he was looking at cork and noted that he saw "a great many boxes. (1665) Anton van Leeuwenhock - Observed living cells in pond water, which he called "animalcules" (1673)

Theodor Schwann - zoologist who observed that the tissues of animals had cells (1839) Mattias Schleiden - botanist, observed that the tissues of plants contained cells (1845) Rudolf Virchow - also reported that every living thing is made of up vital units, known as cells. He also predicted that cells come from other cells. (1850 ) Early Contributions

Cell Theory 1.Every living organism is made of one or more cells. 2. The cell is the basic unit of structure and function 3. All cells arise from pre-existing cells.

Cell Types

Prokaryotes Prokaryotes are very simple cells, probably first to inhabit the earth. Prokaryotic cells do not contain a membrane bound nucleus. DNA of bacteria is circular. Bacteria are prokaryotes. Other features found in some bacteria: – Flagella - used for movement – Pilus - small hairlike structures used for attaching to other cells – Capsule - tough outer layer that protects bacteria, often associated with harmful bacteria

Eukaryotic Cells Eukaryotic cells are more advanced cells. These cells are found in plants, animals, and protists (small unicellular "animalcules"). The eukaryotic cell is have membrane bound organelles

Controlling the Cell Nucleus – contains DNA and acts at the control center for the cell

Framework of the Cell Cytoplasm - jelly-like goo on the inside of the cell Cytoskeleton - the internal framework of the cell Cell membrane – outer boundary of the cell, some stuff can cross the cell membrane.

Protein Production The cell is like a factory. Its product is protein which goes to body to serve different functions. DNA has instructions to build protein These instructions are sent to ribosomes The ribosomes build protein and send it through ER The proteins are delivered to golgi where they are completed and tagged for export outside the cell

Energy in the Cell Chloroplast (Plants ONLY) – do photosynthesis by capturing light energy and converting it into chemical energy (sugar). Mitochondria (BOTH plants and animals) – do cellular respiration which breaks up sugars into a form that the cell can use as energy (ATP).

Plant Cell Has all the components of animal cells with some additional structures. – Chloroplast - Uses sunlight to create food, photosynthesis (only found in plant cells), contains green pigment chlorophyll – Cell Wall - outside the cell membrane of plants and some bacteria, the cell wall serves as support – Central vacuole - large water container, helps maintain a turgor (stiffness) in the plant

Animal Cell versus Plant Cell