Biology 1st Quiz (3) PDF

LESSON 1: CELL THEORY Cell Biology ROBERT HOOKE (1665) greek kytos, “container” - Curator of instrument for the Royal Emerged from Cytology Society of London...

LESSON 1: CELL THEORY Cell Biology ROBERT HOOKE (1665) greek kytos, “container” - Curator of instrument for the Royal Emerged from Cytology Society of London - discoverer of the cell Cytology - first coined the word cell the study of the structure and function of - piece of cork cells. - Latin Cellulae “Little rooms” - Microgaphia published in September Cell Theory 1665. 1. All organisms are made up of cells - The first major publication of the Royal 2. A cell is structural and functional unit of Society life. - The first scientific best-seller. 3. Cells are capable of self reproduction and - inspiring a wide public interest in the new cells come only from pre-existing cells. science of microscopy. Modern Cell Theory ANTON VAN LEEUWENHOEK The cell is the fundamental unit of - a Dutch tradesman and scientist from structure and function in living organisms. Delft, Netherlands. All cells arise from pre-existing cells by - Commonly known as "the Father of division. Microbiology“. Energy flow (metabolism and - Best known for his work on the biochemistry) occurs within cells. improvement of the microscope and for Cells contain hereditary information his contributions towards the (DNA) which is passed from cell to cell establishment of Microbiology. during cell division. - First observation of single-cell organism, “animalcules” Cells - Vacuole of the cell basic structural and functional unit of life - the spermatozoa in 1677 smallest unit of an organism that can function independently Some better-known types of animalcule include: common denominator of all living Actinophrys, and other heliozoa, termed sun organisms. animalcules. Amoeba, termed Proteus animalcules. HISTORICAL BACKGROUNDS Noctiluca scintillans, commonly termed the sea sparkles. Hans and Zacharias Janssen (1590) Paramecium, termed slipper animalcules. Rotifers, termed wheel animalcules. - Credit for the first microscope is usually Stentor, termed trumpet animalcules. given to Zacharias Janssen, around the Vorticella, and other peritrichs, termed bell year 1595. animalcules. - Since Zacharias was very young at that time, it's possible that his father Hans ROBERT BROWN (1833) made the first one, but young Zach took - Scottish botanist over the production. - discovered the nucleus in cell of the - The first compound microscopes orchids. produced by the Janssen's was simply a - described the streaming movement of the tube with lenses at each end. cytoplasm – - The magnification of these early scopes - Brownian Movement ranged from 3X to 9X, depending on the size of the diaphragm openings. MATTHIAS JAKOB SCHLEIDEN (1838) - German botanist - All plant tissues are composed of cell. cham..  - an embryonic plant always arises from a - include two major classification domains: single cell. the bacteria and the archaea. THEODOR SCHWANN (1839) - German zoologist - All animal tissues are composed of cells. - Showed evidence that plants and animals resembled structurally. - Examined cartilage cell. - Originally postulated in 1939 the Cell Theory with 2 tenets. 2 basic Tenets - All organisms are consist of one or more cells. - The cell is the basic structure for all organisms. RUDOLF CARL VIRCHOW (1855) - German doctor, anthropologist, pathologist, pre-historian, biologist and politician - known for his advancement of public health. - Referred to as "the Father of Modern Pathology,“ - considered one of the founders of social medicine. - “Cell arose in only one manner, by cell division of other pre-existing cells. - "omnis cellula e cellula” - 3rd tennet, All cells arise only from preexisting cells. ROBERT REMAK (1855) - A German embryologist, Physiologist, and Neurologist. - discovered that the origin of cells was by the division of pre-existing cells LESSON 2: PROKARYOTIC CELLS Types of Cells - Prokaryotic - Eukaryotic Prokaryotic Cell - Greek πρό- (pro-) "before" + καρυόν (karyon) "nut or kernel“ - lack a nucleus - Lack membrane-bound organelles - tiniest of all cells; 10 times smaller than eukaryotic cell. - most are single-celled organisms - simplest organisms. - abundant in the air, water, soil, and on most objects. cham.. Prokaryotic Cell: Structure Capsule - well organized layer - firmly attached to the cell wall - not easily washed off - can be the cause of various diseases Flaggela - Filamentous protein appendages that enable bacteria to move. Flaggelar Arrangement: Monotrichous- one flagella Amphitrichous- flagella at both ends Lophotrichous- many flagella at the end of the cell Peritrichous- flagella all over entire cell Short Attachment Pili or Fimbria - Latin for 'thread' or 'fiber’; - thinner and shorter than a flagellum. - arisen from the cytoplasm and extend to the plasma membrane, cell wall and capsule. Function: to adhere to one another and to adhere to animal cells and some inanimate objects. Long Conjugation Pili or F/Sex Pili External Structure Function: - Glycocalyx (Capsule, Slime layer) join bacterial cells in preparation for the transfer of - Flagella DNA from one cell to another. - Fimbrae Enable bacteria to transfer genetic material to Glycocalyx another bacterial cell by a process conjugation. - slimy gelatinous material produced by the cell membrane and secreted outside of Cell Wall the cell wall. - surrounds the Cell Membrane - not selectively permeable Function: - anything that can fit ,can pass through the 1. allows the prokaryotes to attach itself to inert cell wall surfaces Functions: 2. protect bacteria from phagocytes - maintains characteristic shape 3. Binds cells together - rigid wall compensates for flexibility of membrane and keeps cell from assuming Slime layer a spherical shape. - not highly organized - provides a rigid platform for surface - not firmly attached to the cell wall. easily appendages detaches from the cell wall and drifts - flagella, pili, cilia away. - counters the effects of osmotic - Pseudomonas species produce slime pressure layer - keeps the cell from bursting - Virulence-ability to cause disease Atypical Cell Wall cham.. Mycoplasma Spores or Endospores - Smallest bacteria (pass through filters for - an internal structure formed by the bacteria) bacterium that makes the bacteria - Very little or no cell wall (very weak to dormant and tough. outside environment) - it ensures the survival of a bacterium - is susceptible to osmotic changes. through periods of environmental stress Archaea Nucleoid - Extreme environmental conditions: - an irregularly-shaped region which has methanogens, halophiles, thermophiles nuclear material without a nuclear - May lack cell wall membrane and where the genetic - Walls : No peptidoglycan, have material is localized. pseudomurein - Genophore - Halophiles -DNA of prokaryotes - Thermophiles -Prokaryotic chromosome -genome of prokaryotic organisms: -a circular, double-stranded piece of DNA, Plasma Membrane of which multiple copies may exist at any - semi permeable barrier time. - encloses the cytoplasm regulates flow into and out of cell Plasmid - selective permeability - Small circular molecules of Composition: double-stranded DNA that are not part of Phospholipid (PL) Bilayer, both hydrophilic and the chromosomes. hydrophobic. - Extrachromosomal DNA Proteins - interspersed between the phospholipid - also found in yeast cell bilayer and acts as pores/channels in movement Binary Fission: Reproduction of materials in/out of the cell. LESSON 3: EUKARYOTIC CELL Internal Structure ANIMAL CELL/PLANT CELL Cytoplasm - the semi-fluid material between the Nucleus plasma membrane (cell membrane) and - The nucleus is the most obvious organelle the nuclear envelope. in any eukaryotic cell. - a type of protoplasm - It is enclosed in a double membrane and - Thick, aqueous, semitransparent, elastic - about 80% water communicates with the surrounding - contains internal cell structures and cytosol via numerous nuclear pores. solutions - Within each nucleus is nuclear chromatin - with organic and inorganic molecules that contains the organism’s genome. - DNA and ribosomes are found here - The DNA stores the organism’s entire encoded genetic information. The DNA is Ribosomes - cytoplasmic structure found in similar in every cell of the body, but prokaryotes and eukaryotes. depending on the specific cell type, some - consist mainly of rRNA and proteins genes may be turned - main function of ribosome is to serve as the site of mRNA translation Nucleolus - protein synthesis, the assembly of - The prominent structure in the nucleus amino acids into proteins. - produces ribosomes, which move out of the nucleus and take positions on the rough endoplasmic reticulum where they are critical in protein synthesis. cham.. Cytosol Golgi Apparatus/ Body/ Vesicles - The cytosol is the "soup" within which all - a single membrane. the other cell organelles reside and where - a stack of membrane-bound vesicles that most of the cellular metabolism occurs. are important in packaging - mostly water macromolecules for transport elsewhere - full of proteins that control cell metabolism in the cell. The stack of larger vesicles is including signal transduction pathways, surrounded by numerous smaller vesicles glycolysis, intracellular receptors, and containing those packaged transcription factors. macromolecules. The enzymatic or hormonal contents of lysosomes, Cytoplasm peroxisomes and secretory vesicles are - This is a collective term for the cytosol packaged in membrane-bound vesicles at plus the organelles suspended within the the periphery of the Golgi apparatus. cytosol. Lysosome Centrosome - Lysosomes contain hydrolytic enzymes - or MICROTUBULE ORGANIZING necessary for intracellular digestion. CENTER (MTOC) They are common in animal cells, but rare - an area in the cell where microtubules in plant cells. Hydrolytic enzymes of plant are produced. cells are more often found in the vacuole. - Plant and animal cell centrosomes play - digestive bags/ suicidal bags similar roles in cell division, and both include collections of microtubules, but Peroxisome the plant cell centrosome is simpler and - membrane-bound packets of oxidative does not have centrioles. enzymes. - During animal cell division, the centrioles - In plant cells, peroxisomes play a variety replicate (make new copies) and the of roles including converting fatty acids centrosome divides. The result is two to sugar and assisting chloroplasts in centrosomes, each with its own pair of photorespiration. centrioles. The two centrosomes move to - In animal cells, peroxisomes protect the opposite ends of the nucleus, and from cell from its own production of toxic each centrosome, microtubules grow into hydrogen peroxide. a "spindle" which is responsible for - hydrogen peroxide to water separating replicated chromosomes into - the two daughter cells. Secretory Vesicle: Cell secretions - e.g. hormones, neurotransmitters - are packaged in Centriole (animal cells only) secretory vesicles at the Golgi apparatus. The - Each centriole is a ring of nine groups of secretory vesicles are then transported to the cell fused microtubules. surface for release. - There are three microtubules in each group. Microtubules (and centrioles) are Cell Membrane part of the cytoskeleton. In the complete - double layer of phospholipids (lipid animal cell centrosome, the two centrioles bilayer). The exposed heads of the bilayer are "hydrophilic" (water loving), meaning are arranged such that one is that they are compatible with water both perpendicular to the other. within the cytosol and outside of the cell. However, the hidden tails of the phosopholipids are "hydrophobic" (water fearing), cham..  - acts as a protective barrier to the green color and the ability to absorb uncontrolled flow of water. The membrane energy from sunlight. is made more complex by the presence of numerous proteins that are crucial to cell Endoplasmic Reticulum activity. These proteins include receptors - It transport lipids, proteins, and other for odors, tastes and hormones, as well materials through the cell. as pores responsible for the controlled - They are of two types of smooth entry and exit of ions like sodium (Na+) endoplasmic reticulum and rough potassium (K+), calcium (Ca++) and endoplasmic reticulum, chloride (Cl-). Smooth Endoplasmic Reticulum Mitochondria - The smooth endoplasmic reticulum is so - provide the energy a cell needs to move, named because it appears smooth by divide, produce secretory products, electron microscopy. contract - in short, they are the power - Smooth ER plays different functions centers of the cell. depending on the specific cell type - They are about the size of bacteria but including lipid and steroid hormone may have different shapes depending on synthesis, breakdown of lipid-soluble the cell type. toxins in liver cells, and control of - Mitochondria are membrane-bound calcium release in muscle cell contraction. organelles, and like the nucleus have a - Lacks ribosomes double membrane. - The outer membrane is fairly smooth. But Rough Endoplasmic Reticulum the inner membrane is highly convoluted, - Rough endoplasmic reticulum appears forming folds (cristae) when viewed in "pebbled" by electron microscopy due to cross-section. The cristae greatly the presence of numerous ribosomes increase the inner membrane's surface on its surface. area. - Proteins synthesized on these ribosomes - It is on these cristae that food (sugar) is collect in the endoplasmic reticulum for combined with oxygen to produce ATP - transport throughout the cell. the primary energy source for the cell. Ribosomes Vacuole - Ribosomes are packets of RNA and - A vacuole is a membrane-bound sac that protein that play a crucial role in both plays roles in intracellular digestion and prokaryotic and eukaryotic cells. the release of cellular waste products. - site of protein synthesis. - In animal cells, vacuoles are generally - Each ribosome comprises two parts, a small. large subunit and a small subunit. - Vacuoles tend to be large in plant cells - Messenger RNA from the cell nucleus is and play several roles: storing nutrients moved systematically along the ribosome and waste products, helping increase cell where transfer RNA adds individual amino size during growth, and even acting much acid molecules to the lengthening protein like lysosomes of animal cells. chain. Cell Wall (plant cells only) Cytoskeleton - made up of polysaccharides. In higher - helps to maintain cell shape. But the primary importance of the cytoskeleton is in cell motility. plant cells, that polysaccharide is usually - The internal movement of cell organelles, as well as cellulose. cell locomotion and muscle fiber contraction could - The cell wall provides and maintains the not take place without the cytoskeleton. shape of these cells and serves as a - The cytoskeleton is an organized network of three primary protein filaments:,microtubules, actin protective barrier. filaments (microfilaments), and intermediate fibers Chloroplast (plant cells only) - organelles found in all higher plant cells. - These organelles contain the plant cell's chlorophyll responsible for the plant's cham.. cham..