Bio 151 Exam 2 Questions And Answers

light microscope (LM) - ANS Visibke light is passed through a speciman and then through glass lenses Magnification - ANS The ratio of an objects image size to its real size Resolution - ANS The measure of the clarity of the image, or the minimum distance of two distinguishable points Contrast - ANS Visible differences in brightness between parts of the sample electron microscope (EM) - ANS Used to study sub cellular structures Scanning electron microscopes SEM's - ANS Focus a beam of electrons onto the surface of a specimen, providing images that look 3-D Transmission Electron Microscope (TEM) - ANS focus a beam of electrons through a specimen cell fractionation - ANS Takes cells apart and separates the major organelles from one another Prokaryotic cells - ANS Only organisms of the domains bacteria and archaea consist of.... Eukaryotic cells - ANS protists, fungi, plants, animals Basic features of all cells - ANS plasma membrane, cytosol, chromosomes, ribosomes Prokaryotic cells have - ANS no nucleus, no membrane bound organelles, dna in an inbound region called the nucleoid. Cytoplasm bound by the plasma membrane Eukaryotic cells have - ANS nucleus and membrane bound organelles. Cytoplasm in the region between the plasma membrane and nucleus plasma membrane - ANS a selective barrier that allows sufficient passage of oxygen, nutrients, and waste to service the volume of every cell Volume - ANS As a cell increases in size it's _____ grows more than it's surface area Nucleus - ANS Contains most of the cells genes and is usually the most conspicuous organelle nuclear envelope - ANS encloses the nucleus, separating it from the cytoplasm Nuclear lamina - ANS The nuclear size of the envelope is lined by ______, which is composed of proteins and maintains the shape of the nucleus Chromosomes - ANS In the nucleus, DNA is organized into discrete units called.... Chromatin - ANS Each chromosome contains one DNA molecule associated with proteins, called ...... Nucleolus - ANS Located within the nucleus and is the site of ribosomal RNA synthesis Ribsomes - ANS Are complexes made of ribosomal RNA and protein In cytosol (free ribosomes) and on the outside of ER or nuclear envelope (bound ribosomes - ANS Ribosomes carry out protein synthesis in two locations Endoplasmic Reticulum (ER) - ANS accounts for more than half of total membrane in many eukaryotic cells, continuous with the nuclear envelope Smooth ER - ANS lacks ribosomes Rough ER - ANS Surface is studded with ribosomes Smooth ER - ANS Synthesizes lipids, metabolizes carbohydrates, detoxifies drugs and poisons, stores calcium ions Rough ER - ANS Has bound ribosomes, which secrete glycoproteins( proteins covalently bonded to carbohydrates). Distributes transport vesicles, secretory proteins surrounded by membranes. Is a membrane factory for the cell Golgi apparatus - ANS Consists of flattened membranous sacs called cisternae Golfi apparatus - ANS Modifies products of the ER. Manufacturers certain macromolecules. Sorts and packages materials into transport vesicles Lysosome - ANS A membranous sac of hydrolysis enzymes that can digest macromolecules Phagocytosis - ANS Some types of cell can engulf another cell by... Autophagy - ANS Lysosomes also use enzymes to recycle the cells own organelles and macromolecules, a process called... Vacuoles - ANS Are large vesicles derived from the ER and golgi apparatus food vacuole - ANS formed by phagocytosis contractile vacuole - ANS Found in many freshwater protists, pump excess water out of cells Central vacoules - ANS Found in many mature plant cells, hold organic compounds and water Mitochondria - ANS Are the sites of cellular respiration, a metabolic process that uses oxygen to generate ATP Chloroplasts - ANS Found in plants and algae, are the sites of photosynthesis Cristae - ANS They have a smooth outer membrane and an inner membrane folded into... mitochondrial matrix - ANS The inner membrane creates two compartments: intermembrane space and ..... Peroxisomes - ANS are specialized metabolic compartments bounded by a single membrane Cytoskeleton - ANS A network of fibers extending throughout the cytoplasm motor proteins - ANS As a cell increases in size it's _____ grows more than it's surface area Cell wall - ANS An extra cellular structure that distinguishes plant cells from animal cells extracellular matrix (ECM) - ANS Animal cells lack cell walls but are covered by an elaborate collagen and proteoglycans and fibrobectin - ANS The ecm is made up of glycoproteins such as.... Integrins - ANS Ecm proteins bind to receptor proteins in the plasma membrane called.. Plasmodesmata - ANS channels through cell walls that connect the cytoplasms of adjacent cells Tight junctions - ANS Membranes of neighboring cells are pressed together, preventing leakage of extracellular fluid Desmosomes - ANS (anchoring junctions) fasten cells together into strong sheets gap junctions - ANS (communicating junctions) provide cytoplasmic channels between adjacent cells selective permeability - ANS allowing some substances to cross it more easily than others Amphipathic - ANS Phospholipids are ________ molecules, containing hydrophobic and hydrophilic regions fluid mosaic model - ANS The membrane is a mosaic of protein molecules bobbing in a fluid bilayer of phospholipids