Chapter 6
cilia and flagella share a common structure: ______
A group of microtubules sheathed by an extension of the plasma membrane, a nasal body that anchors the cilium or flagellum and a motor protein called dynein, which drive the bending movements of a cilium or flagellum
_____ cells also have fibers that form a type of cytoskeleton, constructed of proteins similar to eukaryotic ones
Bacterial
The microtubule assembly of a cilium or flagellum is anchored in the cell by a ______, which is structurally very similar to a centriole, with microtubule triplets
Basal body
Except at the pores, the nuclear side of the envelope is linked by the ________a net like array of protein filaments ( in animal cells it's called intermediate filaments) that maintains the shape of the nucleus by supporting the nuclear envelope
Nuclear lamina
The nucleus shape is maintained by the ___________
Nuclear lamina
The site where DNA is found in prokaryotic cells is called a _______
Nucleoid
Sometimes there are two or more________
Nucleoli
The pores allow passage of RNA in the _________
Nucleus or nuclear membrane
The most abundant glycoprotein in the extracellular matrix of most animal cells is ______which forms strong fibers outside the cells
Collagen
Although cells can differ substantially from 1 another, they share _________
Common features
Microtubules guide vesicles from the ER to the ______and then to the ______
Golgi and plasma membrane
After leaving the ER, many transport vesicles travel to the_________, thought of as a warehouse for receiving, sorting, shipping and even some manufacturing
Golgi apparatus
The ER fuses with the ________ by a vesicle pinching off
Golgi apparatus
Transport vesicles move material from the ER to the_______
Golgi apparatus
There are three main types of fibers that make up the cytoskeleton: _____is the thickest, _______are called actin fibers and are the thinnest and_______ are the middle fibers
Microtubules, microfilaments and intermediate filaments
A high ratio of SA to volume is important in cells that exchange a lot of material with their surroundings and these cells may have many ions, long thin projections from their surface called ______, which increase SA without an increase in volume
Microvilli
In addition to the plasma membrane at its outer surface, a eukaryotic cell has extensive, elaborately arranged internal membranes that divide the cell into compartments known as the _________. The cells compartments provide different environments that support specific metabolic functions, so incompatible processes can occur simultaneously in a single cell
Organelles
_____Transform the energy they acquire from their surroundings
Organisms
The basic fabric of most biological membranes is a layer of__________, which has proteins embedded or attached to its surface
Phospholipids and other lipids
The _______ is usually regarded as the boundary of the living cell, but most cells synthesize and secrete materials extracellularly
Plasma membrane
The ________functions as a selective barrier that allows passage of enough oxygen, nutrients and wastes to service the entire cell
Plasma membrane
______are large vesicles derives from the ER and golgi and are an integral part of a cells Endomembrane system because they perform a variety of functions in different kinds of cells
Vacuoles
The membranes of the Endomembrane system are related either through direct physical continually or by the transfer of membrane segments as tiny________, sacs made of membranes
Vesicles
________in animals is made up of 2 circles known as antrioles to help sort chromosomes during mitosis or miosis
Centrosomes
Plant cells don't have _________and ___________
Centrosomes and lysosomes
In the_________, stacks of thylakoids are inside which are filled with photosynthetic pigment (chloroplasts), a stack is known as a granum and the liquid is called the stroma and DNA is a circular shape
Chloroplasts
_______Found in plants and algae, are the sites of photosynthesis
Chloroplasts
____and ____ work together with the plasma membrane molecules to allow whole cells to move a long fibers outside the cell
Cytoskeletal elements and motor proteins
Amoebas and many other unicellular eukaryotes eight by engulfing smaller organisms or food particles, a process called_________
Phagocytosis
Ribosomes are attached to the cytoplasmic side of the nuclear envelopes outer membrane, which is continuous with______
Rough ER
Vesicles in transit from one part of the cell to another are called______
Transport vesicles
The ________ encloses the nucleus, separating its contents from the cytoplasm
nuclear envelope
_________help break hydrogen peroxide down into water and oxygen
Peroxisomes
Microfilaments are made of _______and________
Actin and myosin
All_______have a cell wall
Bacteria
_________is the ratio of an objects image size to its real size
Magnification
Cell walls are perforated with____
Plasmodesmata
The ______ plays a major role in the growth of plant cells, which enlarge as the vacuole absorbs water
Central vacoule
In plants the _________stores water and solutes
Central vacuole
Mature plant cells generally contain a large _______which develops by the coalescence of smaller vacuoles
Central vacuole
In plants the _________ and the _________have their own DNA and ribosomes, therefore making its own proteins
Chloroplasts and mitochondria
The complex of DNA and proteins making up chromosomes is called________
Chromatin
Within the nucleus, the DNA is organized into discrete units called ___________structures that carry the genetic information. Each of these contains one long DNA molecule associated with many proteins.
Chromosomes
All cells contain _______, which carry genes in the form of DNA and all cells have ________, tiny complexes that make proteins according to the instructions from genes
Chromosomes, ribosomes
A Golgi stack has a distinct structural directionality with the membrane of cisternae on opposite sides of the stag differing in thickness and molecular composition. The two sides of a Golgi stack are referred to as the_____ and the _____face, they act as the receiving and shipping departments of the Golgi
Cis and trans
A vesicle that buds from the ER can add it it's membrane and the contents of its lumen to the________ by fusing with a Golgi membrane on that side. The _______gives rise to vesicles that pinch off and travel to other sites.
Cis face, trans face
The Golgi manufacturers and refined it's products in stages with different _________containing unique teams of enzymes
Cisternae
The membrane of each cisternae in a stack separates its internal space from the ______
Cytosol
______ passing through the plasmodesmata joins the internal chemical environments of adjacent cells
Cytosol
The __________Is such an extensive network of membranes that it accounts for more than half the total membranes in many eukaryotic cells and consist of a network of membranous tubules and sacs called _________
Endoplasmic reticulum, cisternae
Because of the orientation of tubulin dimers, 2 _____ of a microtubule are slightly different. 1 can accumulate or release tubulin at a much higher rate than the other
Ends
mitochondria and chloroplasts both process ________
Energy
In unicellular organisms such as amiba, the cells _______ food and pinch off and combine with the _________vacuole to break down food
Engulf, food
All three types of cell junctions are especially common in________
Epithelial tissue
In a ________cell, most of the DNA is in an organelle called the nucleus, which is bounded by a double membrane
Eukaryotic
Mitochondria are found in nearly all ____cells
Eukaryotic
Not all ______are multicellular
Eukaryotic cells
_________have internal membranes that compartmentalize their functions
Eukaryotic cells
__________means outside
Extracellular
Although animal cells lack wall similar to those of plant cells, they do have an elaborate______
Extracellular martix
The ________of animals and is made up of water and various proteins (collagen, proteoglycan and fibronectin)
Extracellular matrix
Some cells are attached to the extracellular matrix by extracellular matrix glycoprotein such as_______
Fibronectin
After secretory proteins are formed, the ER membrane keeps them separate from proteins in the cytosol, which are produced by_______. Secretory proteins depart from the ER wrapped in the membrane of vesicles from a specialized region called______
Free ribosomes, transitional ER
______Are most like the plasmadesmata of plants although the pores are not lined with membranes
Gap junctions
________Provide cytoplasmic channels from one cell to an adjacent cell and in this way are similar in function to the plasmodesmata is plants. These consist of proteins that surround a poor through which ions, sugars, amino acids and other small molecules may pass. They are necessary for communication between cells in many types of tissues.
Gap junctions
The main ingredients of the ECM are _______ and other carbohydrate containing molecules secreted by the cell
Glycoproteins
Hydrolytic enzymes and lysosomal membranes are made by rough ER and then transferred to the ________for further processing
Golgi
The _______removes some sugar monomers and substitutes others, producing a large variety of carbohydrates, May alter membrane phospholipids and may also manufacture some macromolecules and polysaccharides.
Golgi
The _______is especially extensive in cells specialized for secretion and consists of a group of associated flattened membrane sacs or cisternae
Golgi apparatus
The plasma membrane an organelle membrane also participate directly in the cells________ because many enzymes are built into the membrane
Metabolism
Bundles of _____makeup the core of microvilli of intestinal cells
Microfilaments
_____ seem to be present in all eukaryotic cells
Microfilaments
_______ are thin solid rods and also called actin filament's because they are built from molecules of ______a globular proteins
Microfilaments, actin
_____are used to visualize cells
Microscopes
_________grow from centrosomes and help sort chromosomes
Microtubules
____shape and support the cell and also serve as tracks along which organelles equipped with motor proteins can move
Microtubules
________increase SA
Microvilli
Between primary walls of adjacent cells is the ________a thin layer rich in sticky polysaccharides called pectins
Middle lamella
______ are the sites of cellular respiration, the metabolic process that uses oxygen to drive the generation of ATP by extracting energy from sugars, fats and other fuels
Mitochondria
__________ consists of ribosomes, crista, matrix, DNA, inner membrane, outer membrane and inter membrane space
Mitochondria
____ and ____ have 2 membranes surrounding them, contain ribosomes and circular DNA and are autonomous organelles that grow and reproduce within the cell
Mitochondria and chloroplasts
_____and ______change energy from 1 form to another that cells can use for work
Mitochondria and chloroplasts
The Golgi apparatus _____
Modifies products of the ER, Manufactures certain macromolecules and Sorts and packages materials into transport vesicles
Cell motility generally requires interaction of the cytoskeleton with______
Motor proteins
Larger, more complex organisms including plants and animals, are ________
Multicellular
At the lower limit, the smallest cells known are bacteria called________, these are the smallest packages with enough DNA to program metabolism activities necessary for a cell to sustain itself and reproduce
Mycoplasmas
Thousands of actin filament and thicker filaments made of a protein called ______interact to cause contraction of muscle cells
Myosin
Prokaryotic cells are characterized by having____
No nucleus, DNA in an unbound region called the nucleoid, no membrane bound organelles and cytoplasm bound by the plasma membrane
The ________ is a double membrane and the two membranes are each a lipid bilayer with associated proteins that are separated by a space. This membrane is perforated by pore structures. At the lip of each pore the inner and outer membranes are continuous.
Nuclear envelope
The endomembrane system contains ______
Nuclear membrane, ER, vesicles, Golgi apparatus, plasma membrane, lysosomes and vacuoles
A prominent structure within the non-dividing nucleus is the ____________which appears through the electron microscope as a mass of densely stained granules and fibers adjoining part of the chromatin
Nucleolus
The ______Contains most of the genes in a eukaryotic cell
Nucleus
In ______cells the cytoplasm refers only to the region between the ______and ______
Nucleus and plasma membrane
The eukaryotic cells genetic instructions are housed in the ________and carried out by the _____
Nucleus and ribosomes
Until recently, the resolution barrier prevented cell biologists from using standard light microscopy when studying ________, the membrane enclosed structure within eukaryotic cells
Organelles
Within the cytoplasm of a euk. cell, suspended in cytosol, are a variety of _______of specialized form and function. These membrane bounded structures are absent in almost all prok. cells
Organelles
Nucleus(DNA) -> MRNA -> ribosomes on the ER —(vesicles)—> golgi -> vesicle -> microtubule ->
Outside the cell
Some peroxisomes use _____to break fatty acids down into smaller molecules that are transported to mitochondria and used as fuel for cellular respiration
Oxygen
________is made up of phospholipids, it is outer boundary of cell and it is a selective barrier
Plasma membrane
Plants also have tubes, which communicate exchanging molecules through channels called ______________, proteins imbedded in cells
Plasmodesmata
The chloroplast is a specialized member of a family of closely related plant organelles called______
Plastids
The 2 types of cells are ____and_____
Prokaryotic and eukaryotic
All _____are unicellular
Prokaryotic cells
Many cells secrete proteins that are produced by ribosomes attached to___
Rough ER
The ______ also makes membrane phospholipids, enzymes built into the ER membrane assemble phospholipids from precursors in the cytosol
Rough ER
_______ is a membrane factory for the cell, it grows in place by adding membrane proteins and phospholipids to its own membrane. As polypeptides destined to be membrane proteins grow from the ribosomes, they are inserted into the ER membrane and anchored by their Hydrophobic portions.
Rough ER
_______has ribosomes and is involved in protein synthesis
Rough ER
As a cell increases in size it's _____grows less than its volume
SA
The need for a _____large enough to accommodate the volume helps explain the microscopic size of most cells and the narrow shape of others
SA
_____ are formed by phagocytosis
food vacuoles
Proteins imported from the cytoplasm are assembled with ________into large and small subunits of ribosomes. The subunits then exit the nucleus through the nuclear pores of the cytoplasm, where a large and small subunit can assemble into a ribosome.
rRNA
In eukaryotes, a specialized arrangement of microtubules is responsible for the beating of ____and _____, microtubule-containing extensions that project from some cells
Flagella and cilia
The _______ formed, then fuses with a lysosome who's enzymes digest the food
Food vacuole
All eukaryotic cells have_____, hollow rods constructed from globular proteins called tubulins
Microtubules
All protein is sent to golgi which is the shipping center and then pinch off and the vesicles travel in _________ and corn a protein
Microtubules
Many other eukaryotic cells lack centrosomes with centrioles and instead organize ______by other means
Microtubules
There is much evidence for a __________, a framework of protein fibers extending throughout the nuclear interior
Nuclear matrix
_______makes ribosomes
Nucleolus
The ______is a specialized metabolic compartment bounded by a single membrane. They contain enzymes that remove hydrogen atoms from various substrates and transfer them to oxygen, producing hydrogen peroxide as a by product.
Peroxisome
The cytoskeleton also manipulates the ______, bending it inward to form food vacuoles or other phagocytic vesicles
Plasma membrane
A protein structure called a __________lines each pore of the nuclear envelope and plays an important role in the cell by regulating the entry and exit of proteins and RNA is as well as large complexes of macromolecules
Pore complex
A young plant first secretes a relatively thin and flexible wall called the________
Primary cell wall
Plant cell walls may have multiple layers:______
Primary cell wall: relatively thin and flexible, Middle lamella: thin layer between primary walls of adjacent cells and Secondary cell wall (in some cells): added between the plasma membrane and the primary cell wall
Bacteria and archaea consists of ______cells and protists, fungi, animals and plants all consist of _____cells
Prokaryotic and eukaryotic
The ______ is selective in transporting solutions, the solution inside a vacuole differs in composition from the cytosol
Vacuolar membrane
The DNA is arranged in ____________, made up of DNA and proteins, in eukaryotic cells before cell division
Chromatin
___condenses to form discrete chromosomes as a cell prepares to divide
Chromatin
Prokaryotic cells have no _________and _______
Chromatin and protein
Each eukaryotic species has a characteristic number of_______
Chromosomes
Microtubules are also involved in the separation of ________during cell division
Chromosomes
A tubulin diner consists of 2 slightly different polypeptides ____and _____
A-tubulin and B-tubulin
A microfilament is a twisted double chain of_____
Actin subunits
Lysosomes also use their hydrolytic enzymes to recycle these cells own organic material, a process called_____, where a damaged organelle or small amount of cytosol become surrounded by a double membrane and a lysosome fuses with the outer membrane of this vesicle. The lysosomal enzymes dismantle the inner membrane with the enclosed material and the resulting small organic compounds are released to the cytosol for reuse
Autophagy
The _______spins test tubes holding mixtures of disrupted cells at a series of increasing speeds. At each speed, the resulting force causes a subset of the cell components to settle to the bottom of the tube, forming a pellet. At lower speeds, the pellet consists of larger components and higher speeds result in a pellet with smaller components.
Centrifuge
Within the centrosome is a pair of _____, each composed of 9 sets of triplet microtubules arranged in a ring.
Centrioles
A____ is greater than the sum of its parts
Cell
In the hierarchy of biological organization, the _______is the simplest collection of matter that can be considered a living entity
Cell
_________separates cells into individual components based on masses
Cell fractionation
________enables researchers to prepare specific cell components in bulk and identify their function
Cell fractionation
The solution inside the central vacuole called _____ is the plant cells main repository of inorganic ions
Cell sap
A useful technique for studying cell structure and function is __________which takes cells apart and separates major organelles and other subcellular structures from 1 another
Cell subfractionation
The _____ is an extra cellular structure of plant cells
Cell wall
A disadvantage of electron microscopy is that the methods used to prepare the specimen kill the _____
Cells
All _____have same basic features
Cells
All________are related by descent
Cells
Biologists use microscopes and biochemistry to study______
Cells
Larger organisms do not generally have larger cells than smaller organisms, they have more_______
Cells
_____are as fundamental to the living systems of biology as the atom is to chemistry
Cells
_____have been modified in many different ways
Cells
____are usually too small to be seen by the naked eye
Cells
___rely on the integration of structures and organelles in order to function
Cells
when arranged as tissues or organs, ______remains the organisms basic unit of structure and function
Cells
Extracellular components and connections between cells help coordinate______
Cellular activities
Mitochondria's main job is ___________
Cellular respiration
Microfibrils made of the polysaccharide cellulose are synthesized by an enzyme called______ and secreted to the extracellular space, where they become embedded in a matrix of other polysaccharides and proteins.
Cellulose synthase
Only animals have a ________
Centrosome
The ______________ is in unicellular organisms such as Amiba which is a membrane that collects excess water and pumps it out of the cell
Contractile vacuole
Many unicellular eukaryotes living in fresh water have ____ that pump excess water out of the cell, maintaining a suitable concentration of ions and molecules inside the cell
Contractile vacuoles
_______is the difference in brightness between the light and dark areas of the image
Contrast
A 3-D network formed by microfilaments just inside the plasma membrane helps support the cell shape. This network gives the outer cytoplasmic layer of the cell called the ______the semisolid consistency of a gel, in contrast with the more fluid state of the interior cytoplasm
Cortex
each of the two membranes enclosing the mitochondrion is a phospholipid by layer with a unique collection of embedded proteins. The outer membrane is smooth, but the inner membrane is convoluted with infoldings called_______. The innermembrane divides the mitochondrion into two internal compartments, the first is the______ the inner region between the inner and outer membrane and the second compartment, the ______is enclosed by the innermembrane.
Cristae, inter-membrane space, mitochondrial matrix
Microscopes are the most important tools of _______, the study of cell structure
Cytology
The interior of either type of cell is called the ________
Cytoplasm
Ribosomes in ________make a protein used by cell itself, where as ribosomes in _______go out of the cell to be used by other things
Cytoplasm, plasma membrane
In plant cells, Actin protein interactions contribute to ______a circular flow of cytoplasm within cells. This movement which is especially common in large plant cells speeds the movement of organelles and the distribution of materials within the cell
Cytoplasmic streaming
Improvements in both light microscopy and electron microscopy have revealed the _____, A network of fibers extending throughout the cytoplasm
Cytoskeleton
The ______ gives mechanical support and shape to the cell, provides anchorage, can dismantle and reassemble which changes the shape of the cell and helps in cell motility
Cytoskeleton
The ______occupies only a thin layer between the central vacuole and the plasma membrane
Cytosol
At any given time free ribosomes are suspended in __________while bound ribosomes are attached to the outside of the_________. Bound and free ribosomes are structurally identical and ribosomes can play either role at different times. Most of the proteins made on free ribosomes function within the cytosol and bound ribosomes generally make proteins that are destined for insertion into membrane.
Cytosol, endoplasmic reticulum or nuclear envelope
A major difference between prokaryotic and eukaryotic cells is the location of their ________
DNA
Eukaryotic cells are characterized by having____
DNA in a nucleus bounded by a double membrane, membrane bound organelles and cytoplasm in the region between the plasma membrane and nucleus
______ fasten cells together into strong sheets and attach muscle cells to each other
Desmosomes
Bending involves large motor proteins called _______that are attached along each outer microtubule doublet. These proteins walk along the microtubules of the adjacent doublet, using ATP for energy.
Dyneins
The nuclear lamina and matrix may help organize the ________so it functions efficiently
Genetic material
Most secretory proteins are ________, proteins with carbohydrates covalently bonded to them. The carbohydrates are attached to the proteins in the ER lumen by enzymes built into the ER membrane.
Glycoproteins
As a polypeptide chain grows from a bound ribosomes, the chain is threaded into the ER lumen through a pore formed by a protein complex in the ER membrane. The new polypeptide folds into its functional shape as it enters the__________.
ER lumen
The ER membrane separates the internal compartment of the ER called the__________ from the cytosol
ER lumen (cavity) or cisternal space
Rather than focusing light, the _______focuses a beam of electrons through the specimen or onto its surface
Electron microscope
The ___________system regulates protein traffic and performs metabolic functions
Endomembrane
The ______system contains everything except for mitochondria and cellulose
Endomembrane
Many of the different membrane bounded organelles of the eukaryotic cell are part of the _________which includes the nuclear envelope, the endoplasmic reticulum, the Golgi apparatus, lysosomes, various kinds of vesicles and vacuoles and the plasma membrane. This system carries out a variety of task in the cell, including synthesis of proteins, transport of proteins into membranes and organelles in or out of the cell, metabolism and movement of lipids and detoxification of poisons.
Endomembrane system
The rough ER______
Has bound ribosomes which secrete glycoproteins, distributes transport vesicles and is a membrane factory for the cell
Fibronectin and other extracellular matrix proteins bind to cell surface receptor proteins called _____that are built into the plasma membrane
Integrins
The contents of a chloroplasts are partitioned from the cytosol by an envelope consisting of two membranes, separated by a very narrow______. Inside the chloroplast is another membrane system in the form of flattened, interconnected sacs called ____________where in some regions they are stacked and each stack is called a___________.
Inter membrane space, thylakoids, granum
_______ are named for they are diameter, which is larger than the diameter of microfilaments but smaller than microtubules. They are only found in the cells of some animals and are specialized for bearing tension. Each type is constructed from a particular molecular subunit belonging to a family of proteins whose members include the keratins.
Intermediate filaments
The eukaryotic cytoskeleton, which plays a major role in organizing these structures and activities of the cell is composed of three types of molecular structures:________
Microtubules, microfilaments and intermediate filaments
Intermediate filaments are made primarily of protein called _______
Keratin
_____can magnify effectively to about 1,000 times the size of the actual specimen
Light microscopes
Because the ER membrane is continuous with the nuclear envelope, the space between the two membranes of the envelope is continuous with the_________
Lumen of the ER
A _______ is a membraneous sac of hydrolytic enzymes that many eukaryotic cells used to digest or hydrolyze macromolecules
Lysosome
_______ Carry out intracellular digestion in a variety of circumstances
Lysosomes
________in animals digest or break down damaged organelles
Lysosomes
_______in unicellular organisms is filled with hydrolytic enzymes (digestive enzymes that break down macromolecules)
Lysosomes
______also use enzymes to recycle the cells own organelles and macromolecules, a process called autophagy
Lysosomes
Do you nucleus directs protein synthesis by synthesizing ________according to instruction provided by the DNA, which is then transported to the cytoplasm via the nuclear pores. Once this molecule reaches the cytoplasm, ribosomes translate the molecules genetic message into the primary structure of a specific polypeptide.
MRNA
3 important parameters of microscopy are ______,_______and_______
Magnification, resolution and contrast
Animals have structure that _________, whereas plants have a ___________
Maintain structure, cell wall
The smooth ER functions in diverse ________, which vary with cell type. These processes include synthesis of lipids, metabolism of carbohydrates, detoxification of drugs and poisons and storage of calcium ions. Enzymes of the smooth ER are important in the synthesis of lipids, including oils steroids in new membrane phospholipids and poisons, especially in liver cells.
Metabolic processes
In a ________cell, the DNA is concentrated in a region that is not membrane enclosed called the _______
Prokaryotic, nucleoid
Due to no cell wall, animals have to make up for it with different ___________
Protein structures
Animals have more than 1 junction, unlike plants, but have 3 made of _______
Proteins
______act as a gate
Proteins
The collagen fibers are embedded in a network woven out of ________secreted by cells, which consist of a small core protein with many carbohydrate chains covalently attached
Proteoglycans
The cell crawls along a surface by extending cellular extensions called _______and moving toward them
Pseudopodia
In a light microscope the lenses _____the light in such a way that the image is magnified as it is projected into the eye of camera
Refract
_______is a measure of the clarity of the image and it is the minimum distance 2 points can be separated and still be distinguished as separate points
Resolution
_______is inversely related to the wavelength of the light or electrons a microscope uses for imaging and electron beams have much shorter wavelengths than visible light
Resolution
A type of RNA called ________is synthesized from instructions in the DNA
Ribosomal RNA
________ which are complex is made of ribosomal RNA is and proteins are the cellular components that carry our protein synthesis.
Ribosomes
________makes a protein to be secreted
Rough ER
The ________microscope shows the outside through beams of electrons
Scanning
The ___________is especially useful for detailed study of the topography of a specimen
Scanning electron microscope
Other cells add a ________ between the plasma membrane and the primary wall, which often is deposited in several laminated layers, has a strong and durable matrix that affords cell protection and support
Secondary cell wall
A lysosome enzyme works best in the acidic environment and if it breaks open they released enzymes are not very active because the cytosol has a near neutral pH and excessive leakage from a large number of lysosomes can destroy a cell by _______
Self-digestion
functions of microtubules: ______
Shaping the cell, guiding movement of organelles and separating chromosomes during cell division
Many forms of life exist as _________organisms
Single-celled
Metabolic requirements also impose upper limits on the _____that is practical for a single cell
Size
________helps make lipids, helps with detoxification and stores calcium ions that are used for cell communication
Smooth ER
There are two distinct though connected regions of the ER that differ in structure and function:_____, which lacks ribosomes and ______, which is studded with ribosomes on the outer surface of the membrane
Smooth ER and rough ER
Each type of membrane has a unique composition of lipids and proteins suited to that membranes_______
Specific function
The fluid outside the thylakoids is the ______which contains the chloroplasts DMA and ribosomes and many enzymes
Stroma
The various membranes of the Endomembrane system are not identical in____&_____
Structure and function
Only a limited amount of a particular _______can cross per second, so the ratio of SA to volume is critical
Substance
Euk. Means ________and prok. Means _______
True nucleus, before nucleus
The membrane of the chloroplast divides the chloroplast space into three compartments:______
The inter membrane space, the stroma and the thylakoids space
Microtubules are made of______
Tubulin
Microtubules grow in length by adding _________ and they can also be disassembled to build microtubules elsewhere in the cell
Tubulin dimers
Mitochondria and chloroplasts have similarities with bacteria:_____
enveloped by a double membrane, contain free ribosomes and circular DNA molecules and grow and reproduce somewhat independently in cells
chloroplasts structure includes
Thylakoids, membranous sacs, stacked to form a granum and Stroma, the internal fluid
At _____ The plasma membrane's of neighboring cells are very tightly pressed against each other, bound together by specific proteins. These establish a barrier that prevents leakage of extracellular fluid across a layer of epithelial cells
Tight junctions
In animal cells there are three main types of cell junctions__,___&___
Tight junctions, desmoses and gap junctions
Fascicles concentrated in the vicinity of the Golgi apparatus are engaged in the ______ of material between parts of the Golgi and other structures
Transfer
The _________microscope shows the inside of the cell through beams of electrons
Transmission
The _________is used to study the internal structure of cells
Transmission electron microscope
product of cellular respiration is _______
carbon dioxide
In animal cells, microtubules grow out from a ______ near the nucleus
centrosome
The ECM is made up of glycoproteins such as _____
collagen, proteoglycans, and fibronectin
Ribosomes build proteins in two________ locales
cytoplasmic
The______is a network of fibers that organizes structures and activities in the cell
cytoskeleton
Inside all cells is a semifluid, jellylike substance called _______, in which subcellular components are suspended.
cytosol
Ribosomes carry out protein synthesis in two locations ____
cytosol (free ribosomes), outside of ER or nuclear envelope (bound ribosomes)
Each tubulin protein is a _____, a molecule made up of two subunits
dimer
In a ________, visible light is passed through the specimen and then through glass lenses
light microscope
What are the basic features of all cells?
plasma membrane, cytosol, chromosomes, ribosomes
various techniques enhance contrast and enable cell components to be _____
stained or labeled
The smooth ER ___
synthesizes lipids, metabolizes carbohydrates, detoxifies drugs and stores calcium ions
Three types of cell junctions are common in epithelial tissues: ______
tight junctions, desmosomes and gap junctions