5 History of Cells & the Cell Theory Cell Specialization copyright cmassengale

6 First to View Cells In 1665, Robert Hooke used a microscope to examine a thin slice of cork (dead plant cell walls) What he saw looked like small boxes copyright cmassengale

7 First to View Cells Hooke is responsible for naming cells Hooke called them “CELLS” because they looked like the small rooms that monks lived in called Cells copyright cmassengale

8 Anton van Leeuwenhoek In 1673, Leeuwenhoek (a Dutch microscope maker), was the first to view living things Leeuwenhoek used a simple, handheld microscope to view pond water & scrapings from his teeth copyright cmassengale

9 Beginning of the Cell Theory In 1838, a German botanist named Matthias Schleiden concluded that all plants were made of cells Schleiden is a cofounder of the cell theory copyright cmassengale

10 Beginning of the Cell Theory In 1839, a German zoologist named Theodore Schwann concluded that all animals were made of cells Schwann also cofounded the cell theory copyright cmassengale

The CELL is the basic unit of life because… The characteristics of life are carried out by all organisms, whether they are single-celled or multicellular. copyright cmassengale33

Single-Celled Organisms carry out all the functions of life! 1.Made of CELLS 2.Require ENERGY (food) 3.REPRODUCE 4.Maintain HOMEOSTASIS 5.RESPOND to environment 6.GROW and DEVELOP 7.Have DNA. copyright cmassengale34

Multi-cellular organisms carry out all the functions of life! 1.Made of CELLS 2.Require ENERGY (food) 3.REPRODUCE 4.Maintain HOMEOSTASIS 5.RESPOND to environment 6.GROW and DEVELOP 7.Have DNA. copyright cmassengale35

Multi-cellular Organisms Not all their cells do ALL functions. Instead, their cells differentiate to carry out specialized tasks. copyright cmassengale36 Bone cellsMuscle cellsBlood cells

Multi-cellular Organisms These separate organs and systems work together within the whole organism. copyright cmassengale37

Multi-cellular Organisms The way cells differentiate is by expressing some of their genes, and suppressing other genes. – For example, a muscle cell expresses muscle genes, but not genes for nerve cells. copyright cmassengale38

Multi-cellular Organisms One last thing about multicellular organisms. Multicellular organisms show emergent properties. – These are characteristics that the WHOLE has, that the individual parts do not. copyright cmassengale39

Emergent Properties For example: The light bulb The whole is VERY different than each individual part. 3 parts: tungsten filament, metal base, glass container When studied individually, they do not allow the prediction of the properties of the light bulb. Only when we combine them to form the bulb can these properties be determined. copyright cmassengale40

Emergent Properties For example: A tree The whole is VERY different than each individual part. 3 parts: chloroplasts, xylem tubes, roots When studied individually, they do not allow the prediction of the properties of the tree. Different properties “emerge” when all the parts are added together. copyright cmassengale41

STEM CELLS & copyright cmassengale42

copyright cmassengale43 TotipotentPluripotentMultipotentUnipotent Can differentiate into: Other embryonic cells (and thus any other type of cell) All types of specialized cells A limited number of cells (in the same lineage) One type of cell Found in:EmbryosFetusesUmbilical Cord, blood cells, dental buds Skin Cells, Liver cells Misc. Info:The only type that can create an entirely new creature. The majority of research & controversy is with this type of stem cells. (Induced pluripotency!). Type of stem cells

Stem Cell Potency copyright cmassengale44

Therapeutic Uses of Stem Cells (sometimes aka cell therapy) copyright cmassengale45

Bone Marrow Transplants This technique has been used for over 45 years. Since the cells in bone marrow are multipotent, they have the ability to differentiate into different blood cells. People with leukemia are given transplants with healthy blood. copyright cmassengale46

Organ & Tissue Transplants Donated organs are used to replace those that are dying or diseased. However, the demand FAR outweighs the supply. Stem cells offer the possibility of a renewable source for tissues and organs. Possible areas include: Alzheimer’s disease, spinal cord injury, stroke, burns, heart disease, diabetes copyright cmassengale47

Drug Testing New medications could be tested for safety on differentiated cells generated from human pluripotent cell lines. For example: – Screen anti-tumor drugs on cancer cell lines – Insulin-inducing drugs on pancreatic cells copyright cmassengale48