Chap. 6 (Vcab.) Flashcards
Light Microscope (LM)
Visible light passes through specimen then through lenses, which refract light in a way that specimen is magnefied
Magnification
Ratio of an objects image size to its real size
Resolution
Measure of clarity of image
Contrast
Difference in brightness between light + dark areas of an image
Brightfield
Light passes directly through the specimen
Phase-contrast
Uses light to make unstained, transparent, and colorless specimens visible
Differential interference contrast (Nomarski)
Used to exaggerate differences in density; the image appears almost 3-D
Fluorescence
Uses a special microscope to view objects that emit fluorescent light
Confocal
Laser creates a single plane of fluorescence; out-of-focus light from other planes is eliminated.
Standard Fluorescence
Micrograph is blurry because out-of-focus light is not excluded
Deconvolution
Computer improves quality of images from microscope by increasing resolution + contrast
Super-resolution
Fluorescence microscopy technique that images cellular structures in more detail
Scanning Electron Microscope (SEM)
- Micro. that uses electron beam to scan surface of sample, coated with metal atoms
- Study detail of cell surfaces
Transmission Electron Microscope (TEM)
- Passes electron beam through thin sections stained with metal atoms
- Used to study internal structure of cells
Organelle
Membrane-enclosed structures with specialized functions
Electron Microscope (EM)
- Micro. that uses magnets to focus an electron beam on/through specimen
- 100-fold greater than light micro.
Cell Fractionation
Technique used to separate different components of a cell from each other by disrupting the cell + centrifugating mixture at diff. speeds
Differential Centrifugation
Centrifugate spins test tubes with mixtures of disrupted cells at increasing speeds
Pellet
Force from centrifugation causes cell components to settle at the bottom
Plasma Membrane
Barrier that separates cells interior from exterior environment
Cystosol
Semifluid, jellylike substance, portion of cytoplasm
Chromosomes
Carry genes in form of DNA
Ribosomes
Make proteins according to instructions of genes
Nucleoid
- Non-membrane enclosed region where DNA (chromosomes) is located
- Prokaryote
Cytoplasma
- Gel-like substance that fills inside of cell, where most of cells reactions occur
- In E cells, is region between plasma membrane and nucleus
Plasma Membrane
Membrane outside of cell that is selective, regulating the cell’s chemical composition
Nucleus
Contains genetic material in form of chromosomes
Nuclear Envelope
Double membrane that surrounds nucleus, separating contents from cytoplasma
Nuclear Lamina/ Intermidiate filaments
Protein filaments that line inner surface on nuclear envelope, maintain shape
Pore Complex
Protein structure that lines pores + regulates entry and exit of protein + RNAs
Chromosome
Carries genes made of DNA
Chromatin
Complex of DNA + proteins inside chromosome
Nucleolus
Structure in nucleus containing rRNA
Endomembrane System
Collection of membranes inside + surrounding eukaryotic cell
Vesicles
Membrane-bound sac thats transports substances within cell
Endoplasmic Reticulum (ER)
1 Membrane network of tubules + sacs
2. Separates ER from cystol
3. Main function is to synthesize proteins
Smooth ER
Portion of ER free of ribosomes
Rough ER
Portion of ER with ribosomes
Glycoproteins
Protein with one or more covalently attached carbohydrates
Transport vesicles
Membranous sac that carries molecules made by cell
Golgi Apparatus
Cell organelle that helps process and package proteins and lipid molecules
Lysosome
Membranous sac of hydrolytic enzymes that cells use to digest (hydrolyze) macromolecules
Phagocytosis
Cellular process where cell destroys bacteria/ others by surrouding with cell membrane + briing in to break down
Vacuoles
Large vesicles from the ER and Golgi apparatus
Food Vacuole
Ingesting food particles through phagocytosis, then breaking them down and digesting them using enzymes
Contractile Vacuole
Membranous sac that helps move excess water out of certain freshwater protists
Central Vacuole
In mature plant cell, large membranous sac with diverse roles in growth, storage, and sequestration of toxic substances
Mitochondria
sites of cellular respiration that uses oxygen to make ATP by taking energy from sugars, fats, and other fuels
Chloroplasts
Found in plants + algae, site for photosynthesis
Endosymbiont Theory
Theory that mitochondria and plastids in eukaryotic cells were once free-living prokaryotes that became organelles through a process called symbiosis
Mitochondrial Matrix
Innermost compartment of a mitochondrion, located within the inner membrane
Thylakoid
Flat, membranous sac inside a chloroplast. Convert light energy into chemical energy
Granum
Stack that makes up thylakoids
Stroma
Fluid outside thylakoid containing ribosomes + DNA
Plastids
Small organelles that contain pigment or food in cytoplasma
Peroxisome
Organelle containing enzymes that transfer hydrogen atoms from various substances, making hydrogen peroxide
Cytoskeleton
- Network of fibers extending throughout the cytoplasm
- Mechanical, transport, + signaling functions
Microtubules
Microscopic tubular structure in the cytoplasm of cells
Centrosome
- Cellular structure involved in cell division
- It duplicates and 2 centrosomes move to different ends of cell
- Contains pair of centriole
- Animal cells
Centriole
- Separates chromosomes during mitosis
- Animal cell
Motor Proteins
- Protein that interacts with cytoskeletal elements
- Produces movement of cell
Flagella
Hair-like structure (microtubules) that helps cells move
Cilia
Hair-like projections (microtubules) that move particles/ fluids across cell surface
Dyneins
- Molecular motor that uses ATP to generate force + move along microtubules
- Bend flagella + cilia
Micofilaments
Protein filaments part of the cytoskeleton of eukaryotic cells
Actin
Molecules that build microfilaments
Cortex
- Gel-like outer region of Cykel.
- In E. cells is under plasma membrane
Myosin
- Protein that acts as motor in cells
- Convert chemical energy into ATP, generating movement
Pseudopodia
Arm-like projection that extends from cytoplasm of cell
Cytoplasmic Streaming
Interaction with myosin that speeds distribution of materials in cell
Intermediate Filament
Size is median, between microtunules and microfilaments
Cell wall
Barrier outside cell membrane that provides support + shape
Primary Cell Wall
Thin layer surrounding plasma membrane
Middle Lamella
Thin adhesive layer between primary cell wall + other walls (only in plant cells)
Secondary Cell Wall
Rigid layer between plasma membrane and primary cell wall
Extracellular Matrix (ECM)
Large network of proteins and other molecules that surround, support, and give structure to cells and tissues in the body
Collagen
Glycoprotein in ECM that forms fibers
Proteoglycans
Protein that provides support to ECM
Fibronectin
Glycoprotein that forms cell adhesion, wound healing, and tissue engineering
Integrins
Protein that helps cells attach to other cells in EM
Plasmpdesmata
Small channels that directly connect the cytoplasm of neighboring plant cells to each other, establishing living bridges between cells
Tight Junction
Junction between animal cells that prevents leakage through space between cells
Gap Junction
Junction in animal cells, consisting of proteins surrounding a pore that allows passage of materials between cells
Desmosome
Junction in animal cells that fastens cells together (adhesive)
