Cell Structure & Function

A Little History 1600’s – cork cells – Robert Hooke

Anton van Leeuwenhoek-1600’s Observed “animalcules”

Anton’s Words... my work, which I've done for a long time, was not pursued in order to gain the praise I now enjoy, but chiefly from a craving after knowledge, which I notice resides in me more than in most other men. And therewithal, whenever I found out anything remarkable, I have thought it my duty to put down my discovery on paper, so that all ingenious people might be informed thereof. Antony van Leeuwenhoek. Letter of June 12, 1716

Matthias Schleiden – 1800’s Plant Biologist – started as lawyer Father of cell theory One of first German scientists to accept Darwin’s theory of Evolution

Theodor Schwann -1800’s Medicine – physiology Met with Schleiden Helped with cell theory after realizing that nucleus was in both plant and animal cells

Rudolf Virchow – 1800’s Studied cell division Completed cell theory

Cell Theory All living things are made up of cells. Cells are the smallest working units of all living things. All cells come from preexisting cells through cell division.

Janet Plowe – 1900’s Showed that the cell membrane is an actual structure

George Langford - now Studied movement of vesicles along the cytoskeleton Both myosin tubules and actin filaments

Definition of Cell A cell is the smallest unit that is capable of performing life functions.

Examples of Cells Amoeba Proteus Plant Stem Red Blood Cell Nerve Cell Bacteria

Sizes of cells (Click)Sizes of cells

Two Types of Cells Prokaryotic Eukaryotic

Prokaryotic Do not have structures surrounded by membranes Few internal structures One-celled organisms, Bacteria

Eukaryotic Contain organelles surrounded by membranes Most living organisms PlantAnimal

“Typical” Animal Cell /~ acarpi/NSC/images/cell.gif

“Typical” Plant Cell

Cell Parts Structures/Organell es

Cell Membrane Outer membrane of cell that controls movement in and out of the cell Double layer

Cell Wall Most commonly found in plant cells & bacteria Supports & protects cells

Nucleus Directs cell activities Separated from cytoplasm by nuclear membrane Contains genetic material - DNA

Nuclear Membrane Surrounds nucleus Made of two layers Openings allow material to enter and leave nucleus

Chromosomes In nucleus Made of DNA Contain instructions for traits & characteristics

Nucleolus Inside nucleus Contains RNA to build proteins

Cytoplasm Gel-like mixture filled with proteins Surrounded by cell membrane

Rough Endoplasmic Reticulum Moves materials around in cell ribosomes embedded in surface New proteins are twisted and folded

Smooth Endoplas- mic Reticulum No ribosomes Synthesize lipids Site for enzyme action Storage of enzymes

Ribosomes Each cell contains thousands Make proteins Found on ER & floating throughout the cell

Mitochondria Produces energy through chemical reactions – breaking down fats & carbohydrates Controls level of water & other materials in cell Recycles and decomposes proteins, fats, and carbohydrates

Golgi Bodies Protein 'packaging plant' Move materials within the cell Move materials out of the cell

Cytoskeleton Composed of proteins Movement of vesicles Support for cell Cilia, flagellae, cell division

Lysosome Digestive 'plant' for proteins, fats, and carbohydrates Transports undigested material to cell membrane for removal Cell breaks down if lysosome explodes

Peroxisome Oxidative enzymes - catalase Self- replicating Do not form at Golgi Body Rid body of toxins such as hydrogen peroxide

Vacuoles – vesicles Digestion Secretion Transport Water - vacuole

Vacuoles – in Plants Membrane-bound sacs for storage, digestion, and waste removal Contains water solution Help plants maintain shape

Chloroplast - Plant Where photosynthesis takes place Contains chlorophyll Found in plants, protists

Centrosome/Centrioles - Animal Involved in cell division – formation of spindle Microtubule Organizing Center