General Biology Reviewer.pdf

General Biology Reviewer Lesson 1: CELL THEORY & PARTS OF THE CELL 1590s - Zacharias Janssen, a Dutch eyeglass maker, invented the very first microscope. 1665 – Robert Hooke looked at a cork under a microscope and saw box-shaped structures and called it cells. 1674 – Anton Van Leeuwenhoek, fath...

General Biology Reviewer Lesson 1: CELL THEORY & PARTS OF THE CELL 1590s - Zacharias Janssen, a Dutch eyeglass maker, invented the very first microscope. 1665 – Robert Hooke looked at a cork under a microscope and saw box-shaped structures and called it cells. 1674 – Anton Van Leeuwenhoek, father of microbiology, looked through a pond water under a microscope and observed “animalcules” 1838 – Matthias Schleiden, German botanist stated that plants are made up of cells. 1839 – Theodor Schwann, German Physiologist, stated that animals are also made up of cells. 1855 – Rudolf Virchow stated that cells come from pre-existing cells through cell division. CELL THEORY 1. First Postulate – All living things are made of cells 2. Second Postulate – Cells are the basic units of structure and function of an organism. 3. Third Postulate – Cells come from pre-existing cells. “Omnis cellula e cellula” – Rudolf Virchow Modern Cell Theory 4. Cells carry genetic material which is passed on from cell to cell through cell division 5. All cells have the same structure and chemical composition 6. Energy flow (biochemical process) occurs within cells. CELL STRUCTURES Organelles ▪ Definition - “little organs” ▪ Function: - Specialized structures found in the cell which performs specific functions vital to cellular life. Cell Membrane ▪ Structure - Thin, double layers made up of protein and fat ▪ Function: - Separates the inner contents of the cell from its environment - Regulates the passage of the materials that go in and out of the cell Cell Wall ▪ Structure - Rigid membrane - Made up of cellulose ▪ Function: - Protect, support, and gives structure to the cells - Found only in plant cells Nucleus ▪ Structure - Membrane-bound spherical body - Discovered by Robert brown in 1831 ▪ Function: - Store cell’s DNA - Control and regulate cell activities - Control the synthesis of ribosomes and proteins Nucleolus ▪ Structure - Spherical body found in the nucleus ▪ Function: - Produce and assemble ribosomes Ribosome ▪ Structure - A large complex of protein and RNA ▪ Function: - Site of protein synthesis Mitochondria ▪ Structure - Double-membraned, rod-shaped - Has its own DNA  ▪ Function: - Produces chemical energy used to power a cell in the form of ATP (adenosine triphosphate) Endoplasmic Reticulum ▪ Structure - Interconnected membranous sacs and tubules ▪ 2 types Rough Structure: Ribosomes attached to the surface, giving it the rough texture Function: Modifies proteins synthesized by the ribosomes; makes phospholipids for the cellular membrane. Smooth Structure: no attached ribosomes Function: Produces carbohydrates, lipids, and steroids; stores calcium ions Golgi Body ▪ Structure - A series of flat sacs, resembling layered pancakes ▪ Function - Sort, labels, package, and distribute lipids and proteins. Lysosome ▪ Structure - Spherical bodies that produce enzymes. Only found in animal cells. ▪ Function - Digests down cellular nutrients - Aids in apoptosis (programmed cell death) - Breaks down pathogens - Breaks down worn out or damaged cells Chloroplast ▪ Structure - Disc-shaped organelle found only in plant cells. ▪ Function - Site of photosynthesis - Contains green pigment called chlorophyll Vacuole ▪ Structure - Large space within the cell that is enclosed in a membrane, and it is filled with fluid. Only found in plant cells. (Temporarily found in animal cells) ▪ Function - Stores nutrients and waste products. - Maintain water balance and cell shape Cytoskeleton/Cytoplasm ▪ Structure - Network or protein filaments and fibers - Types: microfilaments, microtubules, and intermediate filaments ▪ Function - Gives structure and shape - Responsible for the movement of the cell - Part of the spindle formation during cell division.