A double layer of phospholipids that makes up plasma and organelle membranes.
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Hydrophobic
Water fearing
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Hydrophilic
Water loving
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Fluidity of the cell membrane
maintained by the weak hydrophobic interactions between the tails of the phospholipids , allowing them to move/drift
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increases fluidity of plasma membrane under cold conditions
cholesterol and more unsaturated fatty acids
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integral proteins
embedded in the phospholipid bilayer, spanning the membrane
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peripheral proteins
The proteins of a membrane that are not embedded in the lipid bilayer; they are bound to the surface of the membrane.
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glycolipids
Membrane carbohydrates that are covalently bonded to lipids.
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glycoproteins
Membrane carbohydrates that are covalently bonded to proteins.
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mosaic
made of a variety of macromolecules (phospholipids, cholesterol, proteins, and carbohydrates)
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Aquaporins
water channel proteins that speed up the rate at which water can pass through the membrane
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channel proteins
have a hydrophilic channel that certain molecules or ions can use as a tunnel to get across the membrane
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carrier proteins
a protein that transports substances across a cell membrane buy binding to the molecules and changing shape
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cell wall
A rigid layer that surrounds the plasma membrane of plant cells and is composed of cellulose
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Plasmodesmata
channels through cell walls that connect the cytoplasms of adjacent cells and allow for cell-to-cell communication
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Light microscope
microscope that uses a beam of light passing through one or more lenses to magnify an object
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Magnification
the ratio of an object's image size to its real size
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Resolution
the measure of the clarity of the image
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Contrast
visible differences in parts of the sample
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organelles
A tiny cell structure that carries out a specific function within the cell
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electron microscope
microscope that forms an image by focusing beams of electrons onto a specimen
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scanning electron microscope
a microscope that produces an enlarged, three-dimensional image of an object by using a beam of electrons rather than light
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transmission electron microscope
An electron microscope used to study the internal structure of thin sections of cells
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cell fractionation
technique in which cells are broken into pieces and the different cell parts are separated using a centrifuge
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prokaryotic cell
A type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles; found only in the domains Bacteria and Archaea.
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Eukaryotic cells
Contain a nucleus and other organelles that are bound by membranes.
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nucleus function
information center of the cell containing the chromosomes
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nuclear envelope
layer of two membranes that surrounds the nucleus of a cell
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nuclear pores
holes in the nuclear envelope that allow materials to pass in and out of the nucleus
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nucleolus
Found inside the nucleus and produces ribosomes
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ribosomes function
particles made of rRNA and proteins that carry out protein synthesis by translating the message found in mRNA
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free ribosomes
ribosomes suspended in the cytosol
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bound ribosomes
attached to the outside of the endoplasmic reticulum or nuclear envelope
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Rough Endoplasmic Reticulum function
An endomembrane system covered with ribosomes where many proteins for transport are assembled.
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Smooth Endoplasmic Reticulum function
An endomembrane system where lipids are synthesized, calcium levels are regulated, carbohydrates are metabolized, and toxic substances are broken down.
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Golgi apparatus function
modifies, packages, sorts, and transports materials made by the endoplasmic reticulum
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nucleus location
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ribosomes location
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Rough Endoplasmic Reticulum Location
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Smooth Endoplasmic Reticulum Location
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Golgi apparatus location
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cis face of golgi apparatus
located near ER. Receiving side of golgi apparatus. Vesicle buds from ER can add its membrane and contents of lumen to this by fusing with golgi membrane.
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trans face of the golgi apparatus
gives rise to vesicles, which pinch off and travel to other sites. Shipping side.
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lysosome function
cell organelle filled with enzymes needed to break down macromolecules (carbs, lipids, nucleic acids, and proteins) as well as old cell parts through autophagy
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lysosome location
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autophagy
lysosomes break down damaged organelles (self-eating)
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peroxisomes
membranous sacs containing hydrolytic enzymes used to catalyze reactions that produce hydrogen peroxide (H2O2)
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food vacuole
A membranous sac formed by phagocytosis of microorganisms or particles to be used as food by the cell.
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contractile vacuole
pump excess water out of protist cells
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central vacuole
A membranous sac in a mature plant cell that holds water and ions
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plasma membrane function
A selectively-permeable phospholipid bilayer forming the boundary of the cells
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cell wall function
A rigid structure that surrounds the cell membrane and provides support to plant cells
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plasma membrane location
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cell wall location
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Endosymbiont Theory
mitochondria and chloroplasts were formerly small prokaryotes that began living with larger cells (early eukaryotic cell engulfed a prokaryotic cell)
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mitochondria location
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Cristae
Infoldings of the inner membrane of a mitochondrion that houses the electon transport chain and the enzyme catalyzing the synthesis of ATP.
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mitochondrial matrix
the space inside the inner membrane of a mitochondrion where the Krebs cycle occurs
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chloroplast function
Site of photosynthesis (makes glucose for plant cells)
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chloroplast location
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Chlorophyll
Green pigment in plants that absorbs light energy used to carry out photosynthesis
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thylakoids
A flattened membrane sac inside the chloroplast where the light dependent reactions occur
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granum
stack of thylakoids
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stroma
The fluid of the chloroplast surrounding the thylakoid membrane where the Calvin cycle occurs
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Compartmentalization
prevents interfering reactions from occurring in the same location, increases surface area for reactions to occur
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cytoskeleton
A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement
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Microtubules definition
A hollow rod composed of tubulin proteins that makes up part of the cytoskeleton in all eukaryotic cells
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Microtubule function
Motility (conveyor belt, cilia, flagella), cell shape, assist in the separating of chromosomes in cell division
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centrioles
Cell organelle that aids in cell division in animal cells only (grow out of centrosome)
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cilia and flagella
hairlike structures that extend from the surface of the cell, where they assist in movement with their beating patterns
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basal body
anchors the cilium or flagellum to the cell
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dynein
motor protein that drives the bending movements of a cilium or flagellum
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Microfilaments definition
thin, solid rods built as double chain of actin subunits
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microfiliments functions
maintain cell shape (bear tension and form crotex), assist in muscle contraction, create the contractile ring during cell division
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pseudopodia
A cellular extension extended and contracted through microfilaments
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cytoplasmic streaming
The motion of cytoplasm in a cell that results in a coordinated movement of the cell's contents.
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intermediate filaments definition
Threadlike proteins in the cell's cytoskeleton that are larger than microfilaments but smaller than microtubules
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intermediate filaments function
support cell shape, anchors organelles in place, and forms the nuclear lamina
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exocytosis
The process by which the vacuole surrounding particles fuses with the cell membrane, forcing the contents out of the cell.
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Endocytosis
process by which a cell takes material into the cell by infolding of the cell membrane
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endomembrane system
A network of membranes inside and around a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles.
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cisternae
flattened membranous sacs that make up the golgi apparatus
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selective permeability
A property of a plasma membrane that allows some substances to cross more easily than others.
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small, nonpolar molecules
molecules that pass through the plasma membrane easily
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large polar molecules and ions
molecules that can only go through the plasma membrane by active transport, proteins pumps, or facilitated transport
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passive transport
the movement of substances across a cell membrane without the use of energy by the cell (high to low concentration)
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active transport
the movement of materials through a cell membrane using energy (low to high concentration)
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diffusion
Movement of molecules from an area of higher concentration to an area of lower concentration (to spread out evenly into the available space)
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dynamic equilibrium
condition of continuous, random movement of particles but no overall change in concentration of materials (roughly equal concentrations on either side of the membrane)
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osmosis
Diffusion of water through a selectively permeable membrane
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support for endosymbiotic theory
chloroplasts and mitochondria are similar to prokaryotes in that they have circular DNA, double membranes, can self-replicate, have ribosomes, and can produce ATP