Campbell Biology 6, A Tour of the Cell

To magnify images by passing visible light through a specimen and glass lenses.

Electron microscopes have significantly higher resolution due to shorter wavelengths of electrons compared to visible light.

They enhance the density of electrons in certain parts of the cell, improving contrast and detail in imaging.

<p>Specimens must be dead for preparation, which may introduce artifacts and limits the study of living cells.</p> Signup and view all the answers

<p>SEM scans the surface of a sample with an electron beam to create detailed topographical images.</p> Signup and view all the answers

<p>Cryo-Electron Microscopy (Cryo-EM) utilizes low temperatures to preserve the cellular environment.</p> Signup and view all the answers

<p>Magnification is the ratio of an object's size to its real size.</p> Signup and view all the answers

<p>Cell fractionation is the process used to separate organelles and subcellular structures from one another.</p> Signup and view all the answers

<p>Cells tend to be narrow and elongated to increase the surface area relative to volume, allowing for more efficient absorption of nutrients and communication.</p> Signup and view all the answers

<p>In prokaryotic cells, DNA is concentrated in a non-membrane enclosed region called the nucleoid, whereas eukaryotic cells have DNA enclosed within a double membrane-bound nucleus.</p> Signup and view all the answers

<p>Microvilli serve to increase the surface area of cells without significantly increasing their volume, enhancing absorption and secretion processes.</p> Signup and view all the answers

<p>The size of a cell is significant for metabolism because it sets limits on the efficiency of substance exchange and metabolic processes due to the surface area to volume ratio.</p> Signup and view all the answers

<p>Organelle membranes divide the cell into compartments that provide distinct environments necessary for specific metabolic processes.</p> Signup and view all the answers

<p>Enzymes embedded in cell and organelle membranes facilitate and regulate specific biochemical reactions necessary for cellular processes.</p> Signup and view all the answers

<p>The plasma membrane is vital as it regulates the entry and exit of substances, thus maintaining homeostasis and allowing communication with the external environment.</p> Signup and view all the answers

<p>Larger organisms consist of more cells instead of larger cells to maintain a favorable surface area to volume ratio for efficient nutrient exchange and communication.</p> Signup and view all the answers

<p>As cell size increases, the surface area increases at a slower rate than the volume, leading to a decreased surface area to volume ratio.</p> Signup and view all the answers

<p>Mycoplasma are the smallest bacteria cells, ranging in diameter from 0.1 to 1.0 µm, representing the lower limit of cell sizes.</p> Signup and view all the answers

<p>Ribosomes translate mRNA's genetic message into polypeptides, serving as the factories for protein synthesis.</p> Signup and view all the answers

<p>Free ribosomes synthesize proteins that function within the cytoplasm, while bound ribosomes create proteins to be inserted into membranes.</p> Signup and view all the answers

<p>The endomembrane system includes structures like the nuclear envelope, ER, and Golgi apparatus, and it is involved in protein synthesis, transport, and detoxification.</p> Signup and view all the answers

<p>Rough ER is studded with ribosomes and is involved in protein synthesis, while smooth ER lacks ribosomes and is involved in lipid synthesis and detoxification.</p> Signup and view all the answers

<p>The smooth ER stores calcium ions, which, when released into the cytosol, trigger muscle contractions.</p> Signup and view all the answers

<p>Enzymes in the smooth ER detoxify drugs by attaching a hydroxyl group to make them more water soluble for excretion.</p> Signup and view all the answers

<p>Glycoproteins are formed in the ER when carbohydrates are covalently bonded to proteins by enzymes in the ER membrane.</p> Signup and view all the answers

<p>The polypeptide is threaded into the ER lumen through a pore and folds into its functional shape as it enters.</p> Signup and view all the answers

<p>Ribosomes are composed of larger and smaller subunits made of rRNA and proteins, which facilitate the translation of mRNA into proteins.</p> Signup and view all the answers

<p>Vesicles transport molecules between different membranes in the endomembrane system.</p> Signup and view all the answers

<p>Smaller cells have a greater surface area relative to their volume, which facilitates efficient nutrient absorption and waste removal.</p> Signup and view all the answers

<p>Microvilli are long, narrow projections that increase the surface area without significantly enlarging the cell volume.</p> Signup and view all the answers

<p>The nuclear envelope encloses the nucleus, separating it from the cytoplasm and regulating the entry and exit of materials.</p> Signup and view all the answers

<p>The pore complex regulates the transport of molecules, including mRNA, in and out of the nucleus.</p> Signup and view all the answers

<p>Histones are basic proteins that assist in folding and packing DNA into compact structures known as chromosomes.</p> Signup and view all the answers

<p>When not dividing, chromatin appears as a diffuse mass and allows for the accessibility of genetic information.</p> Signup and view all the answers

<p>The nucleolus synthesizes ribosomal RNA (rRNA) and assembles it with proteins to form ribosomal subunits.</p> Signup and view all the answers

<p>Free ribosomes are suspended in the cytoplasm, while bound ribosomes are attached to the endoplasmic reticulum or nuclear envelope.</p> Signup and view all the answers

<p>The nuclear matrix provides structural support and helps regulate genetic material within the nucleus.</p> Signup and view all the answers

<p>Internal membranes compartmentalize the cell, creating distinct environments for various organelle processes.</p> Signup and view all the answers

<p>Biological membranes are composed of phospholipids and proteins, which facilitate selective permeability and cellular communication.</p> Signup and view all the answers

<p>The nuclear lamina provides mechanical support to the nucleus and helps maintain its shape.</p> Signup and view all the answers

<p>Larger organisms do not have larger cells; instead, they have a greater number of smaller cells to manage cellular functions.</p> Signup and view all the answers

<p>As a cell prepares to divide, chromosomes condense and become thick enough to be distinguished under a microscope.</p> Signup and view all the answers

<p>Differential centrifugation.</p> Signup and view all the answers

<p>Electron microscopy has significantly higher resolution.</p> Signup and view all the answers

<p>SEM is used to view the topography of a sample.</p> Signup and view all the answers

<p>Vacuoles in plant cells store inorganic ions, maintain cell pressure, and can contain pigments and poisonous substances to aid in growth and protection.</p> Signup and view all the answers

<p>The logistics of carrying out metabolism set limits on cell size.</p> Signup and view all the answers

<p>The contractile vacuole pumps excess water outside the cell to maintain osmotic balance.</p> Signup and view all the answers

<p>All cells have a plasma membrane, cytosol, chromosomes, and ribosomes.</p> Signup and view all the answers

<p>Rough ER is covered in ribosomes which are involved in protein synthesis, while Smooth ER lacks ribosomes and is involved in lipid synthesis and detoxification.</p> Signup and view all the answers

<p>Magnification is the ratio of an object's size to its real size.</p> Signup and view all the answers

<p>In eukaryotic cells, DNA is located in a membrane-bound nucleus.</p> Signup and view all the answers

<p>Food vacuoles are formed by phagocytosis and fuse with lysosomes, where enzymes digest the ingested food.</p> Signup and view all the answers

<p>Glycoproteins serve various functions including cell-to-cell recognition, signaling, and forming part of the extracellular matrix.</p> Signup and view all the answers

<p>Samples must be fixed and often stained to visualize structures.</p> Signup and view all the answers

<p>Vacuoles can contain poisonous substances that deter herbivores from eating the plant.</p> Signup and view all the answers

<p>Cryo-EM allows examination of specimens at low temperatures.</p> Signup and view all the answers

<p>The central vacuole stores cell sap, which includes inorganic ions, and aids in maintaining turgor pressure for cell rigidity.</p> Signup and view all the answers

<p>The plasma membrane regulates what enters and exits the cell.</p> Signup and view all the answers

<p>Surface area increases proportionally less than volume.</p> Signup and view all the answers

<p>The endomembrane system components are connected through physical contact or the transfer of membrane segments via vesicles.</p> Signup and view all the answers

<p>Ribosomes are responsible for protein synthesis.</p> Signup and view all the answers

<p>Smooth ER is involved in lipid synthesis, carbohydrate metabolism, detoxification of drugs, and storage of calcium ions.</p> Signup and view all the answers

<p>The smooth ER contains enzymes that modify drugs by adding hydroxyl groups, making them more water-soluble and easier to excrete.</p> Signup and view all the answers

<p>Cytoplasm includes the area between the nucleus and plasma membrane and contains membrane-bound organelles.</p> Signup and view all the answers

<p>Mycoplasma are the smallest bacteria, measuring 0.1 to 1.0 µm in diameter.</p> Signup and view all the answers

<p>Modifying membrane composition allows the cell to adapt its functions and interactions with its environment as it develops.</p> Signup and view all the answers

<p>Contrast is the difference between light and dark regions of an image.</p> Signup and view all the answers

<p>Some plant vacuoles contain pigments that change color to attract pollinating insects.</p> Signup and view all the answers

<p>Barbiturates induce the proliferation of smooth ER, increasing the number of detoxifying enzymes and necessitating higher doses for the same effect.</p> Signup and view all the answers

<p>The ER lumen is the enclosed space within the endoplasmic reticulum where proteins and lipids are processed and modified.</p> Signup and view all the answers

<p>Transport vesicles carry secreted proteins from the ER to the Golgi apparatus for further processing.</p> Signup and view all the answers

<p>The rough ER inserts polypeptides destined for membranes directly into its own membrane as they are synthesized.</p> Signup and view all the answers

<p>The Golgi Apparatus serves as a warehouse for receiving, processing, and shipping materials within the cell.</p> Signup and view all the answers

<p>The Golgi apparatus has a cis stack located near the ER and a trans stack that packages materials for transport, differing in thickness and molecular composition.</p> Signup and view all the answers

<p>Glycoproteins can have some sugar monomers removed and replaced with others as they are modified in the Golgi apparatus.</p> Signup and view all the answers

<p>Lysosomes prevent self-digestion by having hydrolytic enzymes contained within a membrane and maintaining an acidic internal environment.</p> Signup and view all the answers

<p>Lysosomes digest macromolecules through hydrolysis, using hydrolytic enzymes to break down materials.</p> Signup and view all the answers

<p>Autophagy is the process where lysosomes break down damaged organelles for recycling, allowing cells to renew and maintain themselves.</p> Signup and view all the answers

<p>Inherited lysosomal storage diseases impair the function of hydrolytic enzymes, leading to a buildup of undigested material in lysosomes.</p> Signup and view all the answers

<p>Molecular identification tags, such as phosphate groups, help sort materials to their correct destinations within the cell.</p> Signup and view all the answers

<p>During phagocytosis, macrophages engulf bacteria and fuse the resulting food vacuole with lysosomes to digest the bacteria.</p> Signup and view all the answers

<p>The Golgi apparatus manufactures and modifies polysaccharides, including pectins, which are incorporated into plant cell walls.</p> Signup and view all the answers

<p>When a transport vesicle exits the trans face, it carries products that can be incorporated into the plasma membrane or sent to other destinations.</p> Signup and view all the answers

<p>The transitional ER is responsible for packaging secretory proteins into vesicles for transport to the Golgi apparatus.</p> Signup and view all the answers

<p>The Golgi apparatus is made up of flattened membrane sacs called cisternae, whereas the endoplasmic reticulum consists of a network of membranes.</p> Signup and view all the answers

<p>The cisternal maturation model suggests that the cisternae of the Golgi move and mature as they process proteins, transforming from cis to trans.</p> Signup and view all the answers

<p>Lysosomal enzymes are kept inactive in a neutral pH environment outside the lysosome and are protected by the three-dimensional structure of their proteins.</p> Signup and view all the answers

<p>Phagocytosis is the process where cells engulf and digest foreign particles, like bacteria, using lysosomes to degrade them.</p> Signup and view all the answers

<p>Lysosomes are responsible for hydrolyzing macromolecules and recycling cellular components.</p> Signup and view all the answers

<p>Transport vesicles carrying materials from the ER can merge with the cis face of the Golgi apparatus, allowing for the transfer of cargo.</p> Signup and view all the answers

<p>As glycoproteins transit through the Golgi, they undergo modifications, which can include the removal and replacement of sugar monomers.</p> Signup and view all the answers

<p>Autophagy allows the cell to recycle damaged organelles and maintain a balance of cellular components by surrounding them with membranes and degrading them in lysosomes.</p> Signup and view all the answers

<p>The plus end accumulates and releases tubulins at a higher rate, allowing for faster growth or shrinkage compared to the minus end.</p> Signup and view all the answers

<p>Molecular identification tags, such as phosphate groups, help sort materials and direct transport vesicles to their appropriate destinations.</p> Signup and view all the answers

<p>Centrioles are composed of triplet microtubules arranged in a ring, and they play a key role in organizing microtubules during cell division.</p> Signup and view all the answers

<p>Lysosomal enzymes are optimized to work in the acidic environment of lysosomes, enabling effective digestion of macromolecules.</p> Signup and view all the answers

<p>Dyneins are motor proteins that create movement by 'walking' along microtubules, causing bending of cilia and flagella.</p> Signup and view all the answers

<p>The 9+2 pattern, consisting of nine doublets of microtubules surrounding two central microtubules.</p> Signup and view all the answers

<p>Inherited lysosomal storage diseases result from the impairment of hydrolytic enzymes, leading to the accumulation of undigested materials in lysosomes.</p> Signup and view all the answers

<p>Vacuoles are large vesicles derived from the ER and Golgi apparatus that store various substances and help maintain turgor pressure in cells.</p> Signup and view all the answers

<p>Microfilaments, composed of actin, interact with myosin to facilitate muscle contraction through sliding filament mechanisms.</p> Signup and view all the answers

<p>Intermediate filaments are generally more permanent and do not disassemble easily, providing persistent structural support.</p> Signup and view all the answers

<p>The basal body anchors the microtubule assembly of cilia and flagella and is structured similarly to a centriole.</p> Signup and view all the answers

<p>Plant cell walls are primarily made of cellulose microfibrils and provide structure, protection, and prevent excessive water intake.</p> Signup and view all the answers

<p>The primary cell wall is relatively thin and flexible, allowing for cell growth and expansion in young plant cells.</p> Signup and view all the answers

<p>Cytoplasmic streaming is the circular flow of cytoplasm that enhances the movement of organelles and materials within plant cells.</p> Signup and view all the answers

<p>Cilia act as signal-receiving antennas, transmitting molecular signals from the environment to the cell's interior.</p> Signup and view all the answers

<p>The middle lamella is a layer rich in pectin that glues adjacent plant cells together, providing structural cohesion.</p> Signup and view all the answers

<p>Microtubules form pathways along which motor proteins transport organelles, facilitating their movement within the cell.</p> Signup and view all the answers

<p>The contractile vacuole pumps excess water outside of the cell.</p> Signup and view all the answers

<p>Plant vacuoles can contain poisonous substances that deter herbivores.</p> Signup and view all the answers

<p>Mitochondria are the sites of cellular respiration where glucose and oxygen are converted into ATP.</p> Signup and view all the answers

<p>It explains the origin of mitochondria and chloroplasts as derived from engulfed prokaryotic cells.</p> Signup and view all the answers

<p>The highly folded inner membrane, known as cristae, increases the surface area.</p> Signup and view all the answers

<p>Thylakoids are the sites where the light-dependent reactions of photosynthesis occur.</p> Signup and view all the answers

<p>Peroxisomes transfer hydrogen from various substances into oxygen, forming hydrogen peroxide, which is then detoxified.</p> Signup and view all the answers

<p>The central vacuole stores cell sap, which contains inorganic ions and supports cell growth by absorbing water.</p> Signup and view all the answers

<p>Chromoplasts are pigment-containing organelles that provide yellowish-orange colors to fruits and flowers.</p> Signup and view all the answers

<p>Amyloplasts store starch, while chromoplasts contain pigments for coloration.</p> Signup and view all the answers

<p>The inner membrane divides the mitochondria into the intermembrane space and the mitochondrial matrix.</p> Signup and view all the answers

<p>Chloroplasts can grow, shrink, and reproduce by pinching in two.</p> Signup and view all the answers

<p>The mitochondrial matrix contains enzymes that catalyze steps of cellular respiration.</p> Signup and view all the answers

<p>Centrosomes organize microtubules for the cytoskeleton and anchor a pair of centrioles.</p> Signup and view all the answers

<p>Both cilia and flagella consist of microtubules arranged in a specific pattern, typically a 9+2 structure.</p> Signup and view all the answers

<p>Dyneins are motor proteins that facilitate the bending and movement of cilia and flagella.</p> Signup and view all the answers

<p>Motile cilia can move and propel substances, while nonmotile cilia typically function as signal-receiving antennas.</p> Signup and view all the answers

<p>The 9+0 pattern is associated with nonmotile cilia, lacking central microtubules.</p> Signup and view all the answers

<p>Microfilaments provide structural support and participate in cell movements.</p> Signup and view all the answers

<p>The cortex is a three-dimensional network of microfilaments that supports and shapes the cell's outer layer.</p> Signup and view all the answers

<p>Intermediate filaments have larger diameters and provide more permanent structural support compared to microfilaments.</p> Signup and view all the answers

<p>Cytoplasmic streaming is the circular flow of cytoplasm that aids in the movement of organelles and materials within plant cells.</p> Signup and view all the answers

<p>The basal body has microtubule triplets arranged in a 9+0 pattern.</p> Signup and view all the answers

<p>Vesicles move along the cytoskeleton using motor proteins that facilitate their transport to specific destinations.</p> Signup and view all the answers

<p>Microfilaments and intermediate filaments provide tension-bearing support within the cytoskeleton.</p> Signup and view all the answers

<p>Microtubules are hollow rods that resist compression and provide overall structural support to the cell.</p> Signup and view all the answers

<p>In cells without cell walls, the cytoskeleton provides shape, support, and facilitates movement.</p> Signup and view all the answers

<p>Integrins are receptor proteins that span the plasma membrane and facilitate communication between the cytoskeleton and the ECM, influencing cell behavior.</p> Signup and view all the answers

<p>Plasmodesmata are channels connecting plant cells that allow the passage of water, solutes, proteins, and RNA, ensuring they maintain similar environmental properties.</p> Signup and view all the answers

<p>Tight junctions consist of closely packed plasma membranes that prevent leakage of fluids between cells, thus maintaining barrier integrity.</p> Signup and view all the answers

<p>Desmosomes are anchoring junctions that fasten cells into sheets using intermediate filaments, providing strength and stability to tissues.</p> Signup and view all the answers

<p>The ECM regulates gene activity by communicating through integrins and other ECM proteins that transmit signals to the cell's nucleus.</p> Signup and view all the answers

<p>Gap junctions are protein channels that create cytoplasmic connections between animal cells, allowing ions and small molecules to pass directly between them.</p> Signup and view all the answers

<p>Large proteoglycan complexes provide structural support and regulate the movement of molecules through the ECM, influencing tissue hydration and resilience.</p> Signup and view all the answers

<p>The cytoplasmic side of integrins binds to microfilaments, which helps transmit signals from the ECM to the cytoskeleton, impacting cell behavior and responses.</p> Signup and view all the answers

<p>Mitochondria are responsible for cellular respiration and ATP production using oxygen and glucose.</p> Signup and view all the answers

<p>The theory suggests that an early ancestor of eukaryotic cells engulfed prokaryotic cells, leading to the formation of mitochondria and chloroplasts.</p> Signup and view all the answers

<p>Both mitochondria and chloroplasts have a double membrane structure.</p> Signup and view all the answers

<p>Cristae increase the surface area of the inner membrane, enhancing ATP production.</p> Signup and view all the answers

<p>Thylakoids are stacked, interconnected sacs that house the chlorophyll pigments for photosynthesis.</p> Signup and view all the answers

<p>Peroxisomes contain enzymes that convert hydrogen peroxide into water and are involved in the breakdown of fatty acids.</p> Signup and view all the answers

<p>The cytoskeleton provides structural support and shape to the cell and facilitates movement within it.</p> Signup and view all the answers

<p>Microtubules, microfilaments, and intermediate filaments.</p> Signup and view all the answers

<p>Microtubules assist in the separation of chromosomes during cell division.</p> Signup and view all the answers

<p>The chloroplast membrane creates the intermembrane space, stroma, and thylakoid space, optimizing energy conversion during photosynthesis.</p> Signup and view all the answers

<p>Amyloplasts store starch, while chromoplasts provide pigments that give color to fruits and flowers.</p> Signup and view all the answers

<p>Mitochondria and chloroplasts have dynamic shapes; they can grow, shrink, and reproduce themselves.</p> Signup and view all the answers

<p>Muscle cells require more energy for contraction and movement, hence they have a higher number of mitochondria.</p> Signup and view all the answers

<p>The secondary cell wall provides additional reinforcement and strength to the plant cell, primarily found in wood.</p> Signup and view all the answers

<p>Collagen forms strong fibers in the ECM and accounts for about 40% of the protein in the human body.</p> Signup and view all the answers

<p>The proteoglycan network consists of collagen fibers embedded in proteoglycans bonded to polysaccharides, providing structural integrity to the ECM.</p> Signup and view all the answers

<p>Integrins are receptor proteins that facilitate communication between the cytoskeleton and the ECM, influencing cell behavior.</p> Signup and view all the answers

<p>Plasmodesmata connect plant cells, allowing water, solutes, and small molecules to pass between them.</p> Signup and view all the answers

<p>Tight junctions prevent fluid leakage, desmosomes fasten cells into sheets, and gap junctions create channels for communication.</p> Signup and view all the answers

<p>The middle lamella glues adjacent plant cells together and consists primarily of pectins.</p> Signup and view all the answers

<p>The primary cell wall is thin and flexible, while the secondary cell wall is thicker and more reinforced.</p> Signup and view all the answers

<p>The ECM is mainly composed of glycoproteins, proteoglycans, and other carbohydrate-containing molecules.</p> Signup and view all the answers

<p>Fibronectin binds to integrins, which are receptor proteins that anchor cells to the ECM.</p> Signup and view all the answers

<p>Desmosomes anchor muscle cells together, preventing them from pulling apart during contraction.</p> Signup and view all the answers

<p>The ECM can affect gene activity through signaling pathways facilitated by integrins.</p> Signup and view all the answers

<p>Proteoglycans consist of a small core protein with multiple carbohydrate chains covalently bonded to it.</p> Signup and view all the answers

<p>Gap junctions are formed by membrane proteins that create pores for communication, unlike plasmodesmata, which are lined with membrane.</p> Signup and view all the answers