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Cellular Biology. Cell Structure Cell Function. History of the Cell Theory. 1600’s – Anton van Leeuwenhoek started using the microscope to study nature.
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Cellular Biology Cell Structure Cell Function
History of the Cell Theory • 1600’s – Anton van Leeuwenhoek started using the microscope to study nature. • 1665 – Robert Hooke published Micrographia(containeddrawings of cork sections observed using a microscope. He saw “cells”.) • 1674 – Leeuwenhoek sees tiny organisms swimming in pond water using a microscope. • 1838 – MatthaisSchleiden concludes all plants are made up of cells. • 1839 – Theodor Schwann concludes all animals are made up of cells. • 1855 - Rudolf Virchow – all cells come from existing cells Cork Video
“The Cell Theory” • All living things are composed of cells. • Cells are the basic units of structure and function in living things. • New cells are produced from existing cells.
Levels of Organization • Cell: Functional and structural unit of living things • Tissue: Composed of groups of cells alike in their structure and function. • Nervous • Epithelial (covers and lines the body and organs. Ex. Skin) • Muscle • Connective (bones, blood, cartilage, lymph) • Organ • Organ system • Organism
NucleusFunction Controls most cell processes. • Contains DNA that controls the building of proteins. • Contains chromatin – a granular material that is dispersed throughout the nucleoplasm. (Chromatin is made up of DNA and protein.) • When a cell divides, the chromatin condense and coils up to form chromosomes • Nucleolus - Small dense area within the nucleus that contains RNA and DNA • Plays a role in making proteins….produces ribosomes to be used in manufacturing proteins
Cell Membrane/Cytoplasm • Cell Membrane – thin flexible barrier around a cell…selectively permeable • Cytoplasm – Liquid material inside the cell membrane. Organelles are found in the cytoplasm • Cytoplasm Streaming/Brownian movement
Cell Wall • Cell wall*: Found in many plants, algae, fungi, and bacteria. • The cell wall lies outside the cell membrane • Function To provide support and protection for the cell. • Made mostly of a hard starch known as cellulose, with a jelly like substance known as pectin. • As cell walls become older, they become woody with a substance known as lignin.
Endoplasmic Reticulum & Ribosomes • An “intracellular highway” …transport a canals • Function: Area where cell membrane parts are assembled and some proteins are made. • Rough ER – Produces proteins to be transported “outside” the cell. • Smooth ER - Plays a role in building lipids, regulating enzymes in muscle cells, and breaking down toxic substances in the liver. • Ribosomes • Free Ribosomes: Float around in cytoplasm and make proteins used inside the cell • Bound Ribosomes: Attached to rough ER and make protein used outside the cell
Golgi Apparatus/Bodies • Function: The storage, packaging, and secreting organelle of the cell. • Shaped like stacks of flattened sacks. • Packages proteins made in the rough ER into small packages called vesicles.
Lysosome“Enzyme Sacs” Functions • Made by Golgi bodies and contain digestive enzymes • Break down food particles in the cell • Digests worn out organelles in the cell • Also digests ingested bacteria and other debris (work with White Blood Cells) • Common in animals, fungi, and algae cells. Not found in plants. Lysosome Animations
Mitochondria“power house” • Uses food to produce the high energy molecule ATP. • The site of cellular respiration. • Found in all eukaryotic cells.
Vacuoles* • Sometimes called the “waste dumps of the cell”. • Contain fluid filled sacs that store water, salts, and enzymes. • Vacuoles are commonly found in PLANT cells and some protozoans. • Vacuoles can be very large and take up as much as 90% of a cell’s volume.
Plant Cells Have cell walls chloroplasts large vacuoles No Lysosomes Animal Cells Have No cell walls No chloroplasts No vacuoles (some animal cells may have very small vacuoles) Contain Lysosomes Plant Cells versus Animal Cells
Cytoskeleton • Provides the cell support, structure and ability to move • Made up of protein filaments • Microtubules • Hollow protein tubes that organelles slide along. • Similar to “tracks” • Form centrioles in animal cells during mitosis. • Also form cilia and flagella on the outside of cells to enable cells to move. • Microfilaments • Smaller tubes that form a tough and flexible framework to support the cell.
Prokaryotes (Pro = No) Smaller cells NO true nucleus NO membrane-bound organelles Evolved early…primitive DNA is in the cytoplasm and is a circular mass Eukaryotes (Eu = True) Larger cells (by comparison) Have a nucleus Contain membrane-bound organelles Greater specialization DNA is in the nucleus Prokaryote vs Eukaryote
Endosymbiotic Theory- Mitochondria/chloroplast: Have their own DNA and RNAProduce their own energy and proteinsReproduce on their ownDouble membraneBiochemically similar to prokaryotes
Domain Archae • Kingdom Archaebacteria • Prokaryotic • Unicellular • Characteristics different from “more recognizable” bacteria Domain Bacteria • Kingdom Eubacteria • Prokaryotic • Unicellular • Recognizable….such as e-coli, streptococcus, staph(MRSA) Domain Eukarya Kingdom Protista Kingdom Fungi Kingdom Plantae Kingdom Animalia