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87 Cards in this Set
- Front
- Back
the structure of individual cell components is closely related to their _____.
the overall shape and composition of a cell is also closely related to its ____. |
structure and shape is closely related to function
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what are the two broad categories of cells based on their morphology?
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prokaryotes and eukaryotes
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according to phylogeny, organisms fall into what three broad domains?
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1. bacteria 2. archaea 3. eukarya
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members of the bacteria and archaea are prokaryotic. members of the eukarya are _____
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eukaryotic
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most prominent structure inside a bacterial cell
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chromosome
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define chromosome
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in a bacterial cells, a thread like structure containing a large DNA molecule and small proteins. in eukaryotes, this is found in the nucleus
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DNA is encoded in its sequence of___ ___
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nitrogenous bases
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define gene
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a segment of DNA that contains the information for building an RNA molecule or a polypeptide
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to fit in the cell, the DNA double helix coils on itself with the aid of enzymes to form the __ __ structure
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super coiled
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bacterial chromosomes are found in a localized area of the cell called the _____
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nucleoid
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give characteristics of the nucleoid
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found in in the center of the cell and represents about 20% of the cells volume
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the genetic material in the nucleoid is/is not separated from the rest of the cell interior by a membrane
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is not separated from the rest of the cell
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define plasmids
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in bacterial cells, small, usually circular, supercoiled DNA molecules. Plasmids contain genes but are physically independent of the main, cellular chromosome
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plasmids can be considered auxillary genetic components. true/false?
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true. the genes carried by plasmids are not required under normal circumstances.
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ribosomes manufacture _____
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proteins
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it is common to observe extensive internal ______ in prokaryotes that perform photosynthesis
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internal membranes, which develop as internal foldings of the plasma membrane
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define organelles
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membrane bound compartment inside the cell that contains enzymes or structures specialized for a particular function
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protein filaments that help the bacterial cell maintain shape form the basis of the ____
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cytoskeleton ("cell skeleton")
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define cytoplasm
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the contents of the cell inside the membrane
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when ___ are present in the plasma membrane, their rotation allows aquatic cells to swim through the water
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flagella
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what are cell walls in bacteria and archaea?
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tough, fibrous layer that surrounds the plasma membrane
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brown algae, red algae, fungi, amoebae, slime molds, green plants and animals are all _____
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eukaryotic
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which are larger? eukaryotic cells or prokaryotic cells?
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eukaryotic cells are usually much larger than prokaryotic cells
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what two advantages are offered by the compartmentalization inside eukaryotic cells?
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incompatible chemical reactions can be separated, and chemical reactions become more efficient
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when typical prokaryotic and eukaryotic cells are compared, there are 4 key differences. what are they?
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1. eukaryotic chromosomes are found inside a membrane bound compartment called the nucleus
2. eukaryotic cells are often much larger 3. eukaryotic cells contain extensive amount of internal membrane 4. eukaryotic cells feature a particularly diverse and diverse cytoskeleton |
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define nucleus
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contains the chromosomes and functions as an information storage and processing center
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define nuclear envelope
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a complex double membrane that encloses the nucleus. studded with pore like openings, inside surface is linked to fibrous proteins that form a lattice like sheet called the nuclear lamina, which stiffens the structure and gives shape
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define nuclear lamina
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gives the nuclear envelope its shape
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do chromosomes float freely in the nucleus?
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no, each occupies a distinct area and is attached in at least one location
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the nucleus occupies a distinct area of the nuclear envelope called the ___
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nucleolus. where the RNA molecules found in ribosomes are manufactured
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the nuclear envelope is continuous with an extensive series of membrane bound sacs called the ____ _____
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endoplasmic reticulum, or ER.
the ER extends from the nuclear envelope into the cytoplasm |
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the rough ER manufactures ___, which are packaged into ___ and transported to various locaitons
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proteins that are packed into vesicles for transport
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smooth endoplasmic reticulum (smooth ER) contains ____ that ___ reactions involving lipids
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smooth ER contains enzymes that catalyze reactions involving lipids.
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the ___ ___ is where phospholipids are manufactured
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smooth ER
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the ____ ____ is a reservoir for calcium ions used in signal triggering
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smooth ER
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products of the rough ER pass through the ___ ___ before they reach their final destination
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golgi apparatus
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what are cisternae?
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flattened, membranous sacs which are stacked on top of one another. the cisternae receives products from the rough ER and packages and processes them for delivery
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what are eukaryotic ribosomes?
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ribosomes manufacture proteins. many are attached to the rough ER, and many are scattered throughout the cytosol
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what is the fluid portion of the cytoplasm?
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cytosol
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peroxisomes are centers for ____ reactions
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peroxisomes are centers for oxidation reactions, removing electrons from atoms or molecules. peroxisomes protect the cell by removing the high energy electrons. each is specialized for particular compounds
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lysosomes function as ___ centers
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lysosomes function as digestive centers
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the interior of lysosomes is acidic or basic?
what else does the lysosome contain? |
acidic, because of proton pumps in the lysosome maintaining a pH of 5.0
lysosomes also contain enzymes to aid digestion. |
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what are the two ways that materials are delivered to lysosomes in animal cells?
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autophagy where damaged cells are surrounded by a membrane and delivered to the lysosome.
phagocytosis,where the plasma membrane of a cell surrounds a smaller cell or food particle and engulfs it |
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____ refers to any pinching off of the plasma membrane that results in the uptake of material from outside the cell
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endocytosis "inside cell act"
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___ brings fluid into the cytoplasm via tiny vescilest hat form from infoldings of the plasma membrane
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pinocytosis "drink cell act"
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what system is the primary center for protein and lipid synthesis and processing?
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the endomembrane system (inner-membrane system)
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the cells of plants, fungi, and other groups lack lysosomes. instead they contain ____
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instead of lysosomes, they contain vacuoles.
vacuoles are large, taking up as much as 80% of the cell volume. |
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vacuoles are ___ centers in plant and fungal cells
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storage centers
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the energy to build organelles and do cellular work comes from ___
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ATP
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ATP is produced by the _____
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mitochondria
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the mitochondria has two membranes. the inner membrane is connected to a series of sac like ____
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cristae
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in the mitochondria, the solution inside the inner membrane is called the ___ ___
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mitochondrial matrix
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most algal and plant cells posess an organelle called the ___ where sunlight is converted to chemical energy
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chloroplast
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membrane bound, flattened vesicles called ___ dominate the interior of the chloroplast
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thylakoids
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thylakoids are stacked into piles called ____
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grana
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relationship between thylakoid and stroma?
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The thylakoids are the disk-like stacks in chloroplasts, whereas, the stroma is the fluid of the chloroplasts which surround the thylakoids. Together, the stroma and thylakoids complete photosynthesis:
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in fungi, algae and plants, cells possess an outer ___ ___ in addition to their plasma membrane. animals lack this.
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cell wall
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the final major structural feature that is common to all eukaryotic cells is the ___ , an extensive system of protein fibers
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cytoskeleton
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differential centrifugation, define
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a technique that allowed researchers to isolate particular cell components and analyze their composition. uses a centrifuge to break cells apart and study the individual components
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what are the dominant forces within the cell?
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charge or electrostatic based polarity attractions. gravity has no significance
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does DNA traverse nuclear pores?
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no, it never leaves the nucleus
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what enters the nucleus?
what exits the nucleus? |
ribosomal subunits and various RNA's exit
proteins needed inside enter |
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define viruses
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parasites that use the cell's machinery to make copies of themselves
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the "zip code" that allows proteins to enter only their intended area has come to be called the ___ ___ ___
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nuclear localization signal
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where is the NLS, the nuclear localization signal or "zip code" located on the nucleoplasmin protein?
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the NLS consists of 17 specific amino acids in the tail of the nucleoplasmin protein
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ions, ATP, amino acids and other small molecules diffuse randomly throughout the cell, but the movement of proteins and other large molecules is ___ demanding and tightly ____
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the movement of proteins and other large molecules is energy demanding and tightly regulated
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in the ____ system, proteins that are synthesized in the rough ER move to the golgi apparatus for processing, and from there travel to the cell surface or other destinations
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endomembrane
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according to electron micrographs, cells that secrete digestive enzymes, hormones or other products have large amounts of ___ and ____
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have large amounts of ER and Golgi
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the pulse-chase experiment supports the hypothesis that a secretory pathway exists, and that the __ ___ and ___ ___ function as an integrated endomembrane system
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the rough ER and Golgi apparatus function as an integrated endomembrane system
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the _____ hypothesis predicted that proteins bound for the endomembrane system have a molecular zip code analogous to the nuclear localization signal
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signal hypothesis
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in the Golgi apparatus, new cisternae constantly form at the ___ face, while old cisternae break apart at the ___ face
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new form at the cis face, old break apart at the trans face
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the ____ is a dense and complex network of fibers that helps maintain cell shape by providing structural support
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cytoskeleton
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what are the three distinct cytoskeletal elements in eukaryotic cells?
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actin filaments, intermediate filaments, and microtubules
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in animal cells, ___ is often the most abundant of all protein
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actin
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what is the role of actin?
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maintains cell shape by resisting tension
move cells via muscle contraction divide animal cells in two move organelles in cytoplasm |
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actin's role in movement depends on the specialized protein ____
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myosin, a motor protein
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the movement called ___ ____ occurs when groups of actin filaments grow, creating bulges in the plasma membrane that extend and move the cell.
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cell crawling
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____ _____ are not polar, and serve a purely structural role in eukaryotic cells
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intermediate filaments
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____ are intermediate filaments that make up your skin and provide the strength to resist puncture and abrasion
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keratins
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___ are composed of two proteins called α-tubulin and β-tubulin, and are the largest cytoskeletal components in terms of diameter
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microtubules
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in animals, the microtubule organizing center has a distinctive structure and is called a ____, animals cells contain two bundles of microtubules called ____
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structure is called a centrosome, two bundles of microtubules called centrioles
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microtubules originate from the ___ ____ ____
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microtubule organizing center
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____ provide stability by resisting compression, and are involved in movement by functioning as transport tracks
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microtubules
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define kinesin
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the protein that generates vesicle movement along microtubules.
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define flagella vs cilia
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flagella- generally longer than cilia and usually just one or two per cell, vs many cilia.
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bacteria vs eukaryotic flagella
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bacterial flagella spin like a propellor
eukaryotic flagella whip back and forth |
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how do flagella bend?
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when dynein arms walk along the microtubule doublets on one side of a flagellum, the structure bends
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