Question
click below
click below
Question
Normal Size Small Size show me how
advbio ch4
Question | Answer |
---|---|
Cell theory | One of the major theories of biology, which states that all organisms are made up of cells; cells are capable of self-reproduction and come only from preexisting cells. |
Cell | The smallest unit of life that displays all the properties of life; composed of cytoplasm surrounded by a plasma membrane. |
Surface-area-to-volume ration | Ratio of a cell's outside area to its internal volume; the relationship limits the maximum size of a cell |
Prokaryotic cells | Cells that generally lack a membrane bound nucleus and the membranous organelles typical of eukaryotic cells |
Eukaryotic cells | Type of cell that has a membrane bound nucleus and membranous organelles |
Bacillus | A rod shaped bacterium; a genus of bacteria |
Spirilla | Long rod shaped bacterium that is twisted into a rigid spiral |
Spirochete | Long rod shaped bacterium that is twisted into a flexible spiral |
Cell envelope (prokaryotic cell) | The portion composed of the plasma membrane, the cell wall, and the glycocalyx |
Plasma (cell) membrane | Membrane surrounding the cytoplasm that consists of a phospholipid bilayer with embedded proteins; functions to regulate the entrance and exit of molecules from cell |
Cell wall | Cellular structure that surrounds a plant, protistan, fungal, or bacterial cell and maintains the cell's shape and rigidity; composed of polysaccharides |
Glycocalyx | Gel like coating outside the cell wall of a bacterium. If compact, it is called a capsule; if diffuse, it is called a slime layer |
Capsule | A form of glycocalyx that consists of a gelatinous layer; found in blue green algae and certain bacteria |
Nucleoid | Region of prokaryotic cells where DNA is located; it is not bound by a nuclear envelope |
Cytoplasm | Region of a cell between the nucleus, or the nucleus region of a bacterium, and the plasma membrane; contains the organelles of the cell |
Plasmids | Extrachromosomal ring of accessory DNA in the cytoplasm of prokaryotes |
Ribosomes | Site of protein synthesis in a cell; composed of proteins and ribosomal RNA (rRNA) |
Cyanobacteria | Photosynthetic bacterium that contains chlorophyll and releases oxygen; formally called a blue green algae |
Thylakoids | Flattened sac within a granum of a chloroplast; membrane contains chlorophyll; location where the light reactions of photosynthesis occur |
Flagella | Long slender extension used for locomotion by some bacteria, protozoans and sperm |
Fimbriae | Small bristle like fiber on the surface of a bacterial cell, which attaches bacteria to a surface |
Conjugation pili | In a bacterium, elongated hollow appendage used to transfer DNA to other cells |
Organelles | Small membranous structures in the cytoplasm having a specific structure and function |
Endosymbiotic theory | Explanation of the evolution of eukaryotic organelles by phagocytosis of prokaryotes |
Vesicles | Small membrane bound sac that stores substances within a cell |
Cytoskeleton | Internal framework of the cell, consisting of micro tubules, actin filaments, and intermediate filaments |
Nucleus | Membrane bound organelle within a eukaryotic cell that contains chromosomes and controls the structure and function of the cell |
Nucleoplasm | Semi fluid medium of the nucleus containing chromatin |
Chromatin | Network of DNA strands and associated proteins observed within a nucleus of a cell |
Chromosomes | The structure that transmits the genetic material from one generation to the next; composed of condensed chromatin; each species of has particular number of chromosomes that is passed onto the next generation |
Genes | Unit of heredity existing as alleles on the chromosomes; |
Nucleolus | Dark-staining spherical body in the nucleus that produces ribosomal subunits |
Nuclear envelope | Double membrane that surrounds the nucleus in eukaryotic cells and is connected to the endoplasmic reticulum; has pores that allow substances to pass between the nucleus and the cytoplasm |
Nuclear pores | Opening in the nuclear envelope that permits the passage of proteins into the nucleus and ribosomal subunits out of the nucleus |
Polyribosomes | String of ribosomes simultaneously translation regions of the same mRNA strand during protein synthesis |
rRNA | Ribosomal RNA; structural form of RNA found in ribosomes |
mRNA | Messenger RNA; type of RNA formed from DNA a template and bearing coded information for the amino acid sequence of a polypeptide |
tRNA | Transfer RNA; type of RNA that transfers a particular amino acid to a ribosome during protein synthesis; at one end it binds to the amino acid, and at the other end it has an anticodon that binds to an mRNA condon |
Endomembrane system | Cellular system that consists of the nuclear envelope, ER, Golgi apparatus, and vesicles |
Endoplasmic reticulum | System of membranous saccules and channels in the cytoplasm, often with attached ribosomes |
Rough ER | Membranous system of tubules, vesicles, and sacs in cells; has attached ribosomes |
Smooth ER | Membranous system of tubules, vesicles, and sacs in eukaryotic cells; site of lipid synthesis; lacks attached ribosomes |
Golgi apparatus | Organelle consisting of sacs and vesicles that processes, packages, and distributes molecules about or from the cell |
Lysosomes | Membrane bound vesicle that contains hydrolytic enzymes for digesting macromolecules and bacteria( used to recycle worn out cellular organelles |
Microbodies | Variety of membrane bound vesicles in eukaryotic cells that contain specialized enzymes to perform specific metabolic functions |
Peroxisomes | Enzyme filled vesicle in which fatty acids and amino acids are metabolized to hydrogen peroxide that is broken down to harmless products |
Vacuoles | Membrane bound sac, larger than a vesicle; usually functions in storage and can contain a variety of substances. In plants, the central vacuole fills much of the interior of the cell. |
Central vacuole | In a plant cell, al large, fluid-filled sac that stores metabolites. During growth, it enlarges, forcing the primary cell wall to expand and the cell surface-area-to-volume ratio to increase |
Chloroplast | Membrane bound organelle in algae and plants with chlorophyll containing membranous thylakoids; where photosynthesis takes place |
Chlorophyll | Green photosynthetic pigment of algae and plants that absorbs solar energy; occurs as chlorophyll a and chlorophyll b. |
Mitochondria | Membrane bound organelle in which ATP molecules are produced during the process of cellular respiration; powerhouse of the cell |
Stroma | Region within a chloroplast that surrounds the grana; contains enzymes involved in the synthesis of carbohydrates during the Calvin cycle of photosynthesis |
Granum | Stack of chlorophyll containing thylakoids in a chloroplast |
Plastids | Organelle of plants and algae that is bound by a double membrane and contains internal membranes and/or vesicles (ex. Chloroplasts, chromoplasts, leucoplasts) |
Matrix | Unstructured semi fluid substance that fills the space between cells in connective tissues or inside organelles |
Cristae | Short finger like projections formed by the folding of inner membrane of mitochondria |
Actin filaments | Component of the cytoskeleton; plays a role in the movement of the cell and its organelles |
Intermediate filaments | Rope like assemblies of fibrous polypeptides in the cytoskeleton that provide support and strength to cells; so called because they are intermediate in size between actin filaments and microtubules |
Microtubules | Small cylindrical organelle composed of tubulin protein around an empty central core; present in the cytoplasm, centrioles, cilia, and flagella |
Centrosome | Central microtubule organizing center of cells. In animal cells, it contains two centrioles. |
Centrioles | Cell structure, existing in pairs, that occurs in the centrosome and may help organize a moronic spindle for chromosome movement during animal cell division |
Cillia | Short hair like projections from the plasma membrane, occurring usually in larger numbers |
Compound light microscope | Uses a set of glass lenses to focus light rays passing through a specimen to produce an image that is viewed by the human eye |
Transmission electron microscope (TEM) | Uses a set of electromagnetic lenses to focus electrons passing through a specimen to produce an image, which is projected onto a fluorescent screen or photographic film. |
Scanning electron microscope (SEM) | Uses a narrow beam of electrons to scan over the surface of a specimen that is coated with a thin metal layer. Secondary electrons given off by the metal are detected and used to produce a 3D image on a tv screen. |
Magnification | The ratio between the size of an image and its actual size. |
Resolution | The minimum distance between two objects that allow them to be seen as two separate objects |
Contrast | A difference in the shading of an object compared to its background |
Confocal microscopy | Uses a laser beam scanned across the specimen to focus on a single shallow plane within a cell. a series of optical sections can be combined to create a 3D image which is displayed and rotated on a computer screen |
Video enhanced contrast microscopy | The computer makes the darkest areas of the original image much darker and the lightest areas of the original much lighter. |
Mesosomes | Internal pouches formed by the plasma membrane in prokaryotic cells; most likely increase the internal surface area for the attachment of enzymes that are carrying on metabolic activities |
Chromoplasts | Plastic that contains pigments that result in yellow, orange or red color. Responsible for the color of fall leaves, fruits, carrots, and some flowers. |
Leucoplasts | Plastid that are generally colorless that synthesize and store starches and oils. Potatoes contains these. |
Motor molecules | Proteins that can attach, detach, and reattach farther along an actin filament |
Myosin | Motor molecule that uses ATP to pull actin filaments along its way; has both a head and tail; associated with actin filaments |
Kinesin and dynein | Motor molecules associated with Microtubules; kinesin moves vesicles or organelles in an opposite direction from dynein |
Basal body | A structure that lies at the base of cilia and flagella and may direct the organization of Microtubules within these structures; a basal body may do for a cilium or flagellum what the centrosome does for the cell. |
A cell's small size allows them to maintain ______,which facilitates the transport of nutrients and wastes into and out if the cell. | A large surface area to volume ratio |
How is most DNA stored in a prokaryote? | Stored in a single coiled chromosomes |
Endosymbiotic theory | Proposes that double membrane bound organelles such as mitochondria and chloroplasts ( which have their own DNA separate from the nucleus's) were once independently living prokaryotes which were engulfed by a larger cell. |
Functions of the Golgi membrane | Synthesis and packing of materials for transport and the production of lysosomes |
What is the purpose of vacuoles? | They store material, dispose of wastes, and, especially in place, maintain water balance |
The surface area to volume ratio defines what aspect of the cell? | It's size |
What best distinguishes a prokaryotic cell from a eukaryotic cell? | Prokaryotic cells do not have a membrane bound nucleus and organelles while eukaryotic cell do |
Of the following, which structures are found in prokaryotic cells: cell wall, ribosomes, thylakoids, chromosome, plasma membrane, nucleus, flagellum, Nucleolus, chloroplasts, capsule, plasmid, enzymes, DNA, mitochondria | Plasmid, ribosomes, enzymes, DNA, mitochondria |
A spherical shaped prokaryotic cell is called a | Coccus |
Which organelle most likely originated by invagination of the plasma membrane? | Nucleus |
What organelle(s) contain their/its own DNA, suggesting they were once independent prokaryotes? | Mitochondria and chloroplasts |
What are found in the nucleus? | Chromatin that condenses to chromatin, Nucleolus that produces RNA, nucleoplasm instead of cytoplasm |
The _____is(are) responsible for protein synthesis in a cell. | Ribosomes |
What is the basic unit of hereditary info? | Gene |
Vesicles from the rough ER most likely are on their way to _____ | The Golgi apparatus |
Lysosomes function in _____ | Intercellular digestion |
What is responsible for the synthesis of proteins that are being exported from the cell? | Rough ER |
Vesicles with specific metabolic functions in a cell are called | Microbodies |
These micro bodies break down fatty acids and contain catalase to break down hydrogen peroxide. | Peroxisomes |
What organelle is involved in cellular respiration? | Mitochondria |
Which organelle releases oxygen? | Chloroplasts |
What are found in chloroplasts? | Grana, thylakoids, stroma |
True or false; actin filaments are located under the plasma membrane. | True |
True or false: Microtubules are organized by centrosomes | True |
True or false: intermediate filaments are associated with the nuclear envelope | True |
True or false: motor molecules move materials along intermediate filaments | False; actin filaments |
Do cilia and flagella have a 9+0 pattern of Microtubules, the same as basal bodies? | Yes |
Do cilia a flagella contain myosin that pulls on actin filaments? | No |
Are cilia and flagella organized by basal bodies derived from centrioles? | Yes |
What are cell inclusions and macromolecules measured in because they are so small? | Nanometers |
Why is a small cell size for advantageous for exchanging molecules? | It has a greater surface area to volume ratio |
Why are cells alive but macromolecules are not? | Unlike macromolecules, cells have the ability to reproduce and only come from preexisting cells |
Explain why a large surface area to volume ratio is needed for the proper functioning of cells | The movement of sufficient materials into and out of the cell requires an adequately large surface area relative to cell volume. Cell size is limited by the amount of surface area. |
Coccus | Spherical shaped bacterium |
What is the important of glycocalyx in prokaryotic cells? | It Aids against drying out and helps bacteria resist a hosts immune system and helps bacteria to attach to almost any surface |
Purpose of plasma or cell membrane | Regulates the entrance and exit of substances into and out of the cytoplasm. |
The semifluid solution composed of water and inorganic and organic molecules encased by a plasma membrane | Cytoplasm |
How do prokaryotic ribosomes differ from those of eukaryotes | Prokaryotic ribosomes are smaller than eukaryotic ribosomes |
Cyanobacteria contain what extensive internal membranes in their cytoplasm | Thylakoids |
What three things does the flagella consist of? | A filament, a hook, and a basal body( a series of rings anchored in a cell wall and membrane) |
How does the flagellum of the prokaryotic cells differ from the eukaryotes | The prokaryotic flagellum rotates 360 degrees while the eukaryotic flagellum moves in a whip like motion |
The number and location of flagella can be used to help distinguish different ____ of prokaryotes | Types |
Are Fimbriae involved with lovomotion? | No |
What are Fimbriae involved in? | Attaching prokaryotes to a surface |
How does the ER communicate with the Golgi body? | By means of transport vesicles |
A liver cell whose function is partly to detoxify drugs and other ingested compounds contains a greater proportion of which organelle that accomplishes this task? | Smooth ER |
A nerve cell whose job is to conduct electrical signals across long distances contains more of what organelle relative to other cells? | Plasma membrane |
A red blood cell can____ it's nucleus to increase the surface area needed to carry oxygen in the blood. | Eject |
Describe the functions of the bacterial cell envelope, cytoplasm, and external structures | Cell envelope: mesosome, plasma membrane, cell wall, glycocalyx; Cytoplasm: inclusion bodies, Nucleoid, ribosomes; Appendages: conjugation pilus, Fimbriae, and flagellum |
Summarize the benefits of compartmentalization found in cells | Separates various metabolic processes; localizes enzymes, substrates, and products; and allows cells to become specialized |
Why do organelles increase cell efficiency and function? | They effectively divide cellular work so that incompatible processes can occur simultaneously. This division of labor enables the cell to more quickly respond to environmental changes |
Explain the origin of the nucleus, chloroplast, and the mitochondria of eukaryotic cells | Nucleus: likely evolved from the invagination of the plasma membrane; Mitochondria and Chloroplasts: thought to have evolved when a larger eukaryotic cell engulfed a smaller prokaryotic cell and eventually became dependent on the smaller organism |
What three things( information wise) are contained inside the nucleus? | Genetic info that is passed from cell to cell and generation to generation, specified info that ribosomes use to carry out protein synthesis, and instructions for copying itself |
What is special about skeletal muscle cells? | They can have more than one nucleus |
How many proteins line each pore in the nuclear envelope? | 8 |
Chromatin is the combination of what two things? | Proteins and nucleic acids |
Chromosomes are the carriers of what? | Genetic info |
Genetic info is organized on the chromosomes as what? | Genes ( basic unit of heredity) |
Where is rRNA produced? | In the nucleolus |
What does mRNA( a mobile molecule) act as for DNA(a sedentary molecule which specifies the sequence of amino acids in a protein)? | An intermediary |
tRNA participates in the assembly of amino acids into a polypeptide by recognizing what two things? | mRNA and amino acids during protein synthesis |
How is the nucleus able to communicate with the cytoplasm? | Through nuclear pores in its nuclear envelope |
Why do pancreatic cells have many ribosomes? | They produce secretions that contain proteins |
What causes a ribosome to bind to the ER? | Binding occurs only if the protein being synthesized by a ribosome begins with a sequence of amino acids called a signal peptide. |
What is termed the central dogma of molecular biology? | The DNA-mRNA-protein sequence of events |
Distinguish between the chromatin and chromosomes within the nucleus | Chromatin is made up of stands of DNA combined with proteins. When these strands condense and coil up, rod like structures called chromosomes are formed. |
What is the importance of nuclear pores? | Cells tightly regulate what enters and exits the nucleus by the user of nuclear pores. |
How are endomembrane vesicles able to fuse with organelles? | Heredity info encoded in genes located in the nucleus is transcribed into RNA molecules. Amino acid sequence is determined by RNA sequence through translation. Polypeptides produced from RNA are then folded into 3D structure that has a biological function |
What does the endomembrane system consist of? | Nuclear envelope, membranes of the ER, googling apparatus, and several types of vesicles |
What is the endomembrane system continuous with? | The nuclear envelope |
The _____ usually consists of a stack of 3 to 20 slightly curved flattened saccules whose appearance can be compared to a stack of pancakes. | Golgi apparatus |
The cis side of the Golgi apparatus is directed towards the ____ and the trans side is directed toward the ______ in animal cells. | ER, plasma membrane |
White blood cells have a greater proportion of what organelle than other cells because their specialized function is to digest foreign bodies like pathogens. | Lysosomes |
Where do secretory vesicles take proteins where they exit the cell by exocytosis? | Plasma membrane |
Contrast the structure and functions of rough and smooth ER. | Rough ER contains ribosomes while smooth ER doesn't. Rough ER synthesizes and modifies proteins while smooth ER synthesizes lipids. |
Describe the relationship between the components of the endomembrane system. | Transport vesicles from ER go to Golgi body to modify their contents and repackages them in new vesicles to be delivered to different specific locations. Incoming food and particles are packaged inside vesicles and delivered to lysosomes for break down. |
How would cellular function be affected if the Golgi body ceased to function? | It would prevent materials from reaching their necessary destinations thus disrupting cellular function and likely leading to cell death |
The enzymes in Peroxisomes are synthesized by what and then transported into a Peroxisome from the cytoplasm? | Free floating ribosomes |
How are Peroxisomes used in plant cells? | Germinating seeds require Peroxisomes to oxidize fatty acids into molecules that can be converted to sugars needed by the growing plant. Also Peroxisomes carry out the opposite reaction of photosynthesis in leaves. |
What do contractile vesicles do? | They rid the cell of excess water |
In fat cells, how much of the volume of the cell does the lipid enforced vacuole take up? | 2/3 |
The watery fluid that the vacuole is filled with that gives added support to the cell | Cell sap |
Structure and function of lysosomes v Peroxisomes | Both are membrane bound vesicles that enclose enzymes. Lysosomes digest material taken into the cell and destroy nonfunctional organelles and cytoplasm. Peroxisomes break down fatty acids. |
Where are the lysosomes and Peroxisomes produced in The cell. | Lysosomes: enzymes produced in ER and loaded into the vesicle by the Golgi apparatus; Peroxisome: enzymes made in the cytoplasm and transported into the vesicle |
Chloroplasts have a what kind of membrane system. | Three membrane system |
What does the double membrane of chloroplasts enclose? | Semifluid stroma, which contains enzymes and thylakoids( dislike sacs formed from the third membrane) |
Chlorophyll and the other pigments that capture solar energy are located in what membrane of chloroplasts? | The thylakoid membrane |
The inner membrane of mitochondria is highly convicted into folds called _____ that project into the matrix, | Cristae |
What is the purpose of cristae? | Increase the surface area of the inner membrane |
The inner membrane encloses a semifluid matrix, which contains what two things? | Mitochondrial DNA and ribosomes |
Summarize the roles of mitochondria and chloroplasts | Both have roles I energy related reaction in cell. Mitochondria: carries out cellular respiration in which carbs are broken down to produce ATP. CHLOROPLASTS: carry out photosynthesis in which solar energy is used to synthesize carbs |
Why do chloroplasts and mitochondria contain complex internal membrane structures? | Mitochondria: provides large surface area that houses enzymes involved in cellular respiration. Chloroplasts: complex membranes of the thylakoids in chloroplasts provide a large area to contain chlorophyll and other pigments involved in photosynthesis |
Actin filaments occur in what two forms? | Mesh like networks or bundles |
Each actin filament contains two chains of globular actin monomers twisted about one another in what manner? | Helical |
What pattern do flagella and cilia have? | 9+2 pattern of Microtubules |
Differentiate between the components of the cytoskeleton and how they provide support to the cell. | Microtubules: help maintain cellular shape and provide an internal road system used to transport intracellular molecules. Intermediate filaments: anchor cells to each other and components in the External environment. Actin filaments:cellular movement |
How is ATP used to produce movement in a cell? | Cilia and flagella are both composed of Microtubules arranged in a particular pattern and enclosed by the plasma membrane. Cilia are shorter than flagella. ATP is used to produce cellular movement via Microtubules. |
Describe the role of motor molecules and Microtubules in cilia and flagella | Cellular movement from Microtubules is accomplished via motor molecules that use ATP. |