Bio 101 Test2
Crista
(plural, cristae) An infolding of the inner membrane of a mitochondrion in which is embedded the electron transport chain and the enzyme catalyzing the synthesis of ATP.
flagellum
(plural, flagella) A long cellular appendage specialized for locomotion. The flagella of prokaryotes and eukaryotes differ in both structure and function. Like cilia, eukaryotic flagella have a 9 + 2 arrangement of microtubules covered by the cell's plasma membrane.
granum
(plural, grana) A stack of hollow disks formed of thylakoid membrane in a chloroplast. Grana are the sites where light energy is trapped by chlorophyll and converted to chemical energy during the light reactions of photosynthesis.
mitochondrion
(plural, mitochondria) An organelle in eukaryotic cells where cellular respiration occurs. Enclosed by two concentric membranes, it is where most of the cell's ATP is made.
nucleus
(plural, nuclei) (1) An atom's central core, containing protons and neutrons. (2) The genetic control center of a eukaryotic cell.
plasmodesma
(plural, plasmodesmata) An open channel in a plant cell wall through which strands of cytoplasm connect from adjacent cells.
The purpose of cellular respiration is the production of _____. (ebook Module 4.13)
. Cellular respiration produces ATP for use in the cell's enzyme reactions that require energy.
A normal size range for a typical eukaryotic cell is _____. (ebook Module 4.1)
10 to 100 micrometers
First microscope was used in
17th century
ribosome
A cell structure consisting of RNA and protein organized into two subunits and functioning as the site of protein synthesis in the cytoplasm. The ribosomal subunits are constructed in the nucleolus.
nucleoid
A dense region of DNA in a prokaryotic cell.
lysosome
A digestive organelle in eukaryotic cells; contains hydrolytic enzymes that digest the cell's food and wastes.
nuclear envelope
A double membrane, perforated with pores, which encloses the nucleus and separates it from the rest of the eukaryotic cell.
glycoprotein
A macromolecule consisting of one or more polypeptides linked to short chains of sugars.
central vacuole
A membrane-enclosed sac occupying most of the interior of a mature plant cell, having diverse roles in reproduction, growth, and development.
vacuole
A membrane-enclosed sac that is part of the endomembrane system of a eukaryotic cell, having diverse functions.
organelle
A membrane-enclosed structure with a specialized function within a cell.
transmission electron microscope (TEM)
A microscope that uses an electron beam to study the internal structure of thinly sectioned specimens.
scanning electron microscope (SEM)
A microscope that uses an electron beam to study the surface architecture of a cell or other specimen.
rough ER
A network of interconnected membranous sacs in a eukaryotic cell's cytoplasm. Rough ER membranes are studded with ribosomes that make membrane proteins and secretory proteins.
endomembrane system
A network of membranes inside and around a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles.
cytoskeleton
A network of protein fibers in the cytoplasm of a eukaryotic cell; includes microfilaments, intermediate filaments, and microtubules.
micrograph
A photograph taken through a microscope.
endosymbiosis
A process by which the mitochondria and chloroplasts of eukaryotic cells probably evolved from symbiotic associations between small prokaryotic cells living inside larger cells.
Cell wall
A protective layer external to the plasma membrane in plant cells, bacteria, fungi, and some protists; protects the cell and helps maintain its shape.
vesicle
A sac made of membrane in the cytoplasm of a eukaryotic cell.
centriole
A structure in an animal cell composed of cylinders of microtubule triplets arranged in a 9 and 0 pattern. An animal usually has a centrosome with a pair of centrioles involved in cell division.
nucleolus
A structure within the nucleus of a eukaryotic cell where ribosomal RNA is made and assembled with proteins imported from the cytoplasm to make ribosomal subunits.
extracellular matrix (ECM)
A substance in which the cells of an animal tissue are embedded; consists of protein and polysaccharides.
chromosome
A threadlike, gene-carrying structure found in the nucleus of a eukaryotic cell and most visible during mitosis and meiosis; also, the main gene-carrying structure of a prokaryotic cell. Chromosomes consist of chromatin, a combination of DNA and protein.
transport vesicle
A tiny membranous sac in a cell's cytoplasm carrying molecules produced by the cell. The vesicle buds from the endoplasmic reticulum or Golgi and eventually fuses with another membranous organelle or the plasma membrane, releasing its contents.
prokaryotic cell
A type of cell lacking a membrane-enclosed nucleus and other membrane-enclosed organelles; found only in the domains Bacteria and Archaea.
eukaryotic cell
A type of cell that has a membrane-enclosed nucleus and other membrane-enclosed organelles. All organisms except bacteria and archaea are composed of eukaryotic cells.
endoplasmic reticulum (ER)
An extensive membranous network in a eukaryotic cell, continuous with the outer nuclear membrane and composed of ribosome-studded (rough) and ribosome-free (smooth) regions. See also rough ER; smooth ER.
electron microscope (EM)
An instrument that focuses an electron beam through, or onto the surface of, a specimen. An electron microscope achieves a hundredfold greater resolution than a light microscope.
intermediate filament
An intermediate-sized protein fiber that is one of the three main kinds of fibers making up the cytoskeleton of eukaryotic cells. Intermediate filaments are ropelike, made of fibrous proteins.
light microscope (LM)
An optical instrument with lenses that refract (bend) visible light to magnify images and project them into a viewer's eye or onto photographic film.
peroxisome
An organelle containing enzymes that transfer hydrogen from various substrates to oxygen, producing and then degrading hydrogen peroxide.
chloroplast
An organelle found in plants and photosynthetic protists that absorbs sunlight and uses it to drive the synthesis of organic molecules (sugars) from carbon dioxide and water.
Golgi apparatus
An organelle in eukaryotic cells consisting of stacks of membranous sacs that modify, store, and ship products of the endoplasmic reticulum.
Digestive cells produce many enzymes that break down ingested food. These cells have a large number of ribosomes _____. (ebook Module 4.8)
Correct. The rough endoplasmic reticulum is responsible for producing proteins that will be inserted into membranes, packaged in certain organelles, or exported from the cell.
cytoplasm
Everything inside a cell between the plasma membrane and the nucleus; consists of a semifluid medium and organelles.
A researcher made an interesting observation about a protein made by the rough endoplasmic reticulum and eventually used to build a cell's plasma membrane. The protein in the membrane was actually slightly different from the protein made in the ER. The protein was probably altered in the _____. (ebook Module 4.9)
Golgi apparatus
The first microscope used was the
Light microscope
thylakoid
One of a number of disk-shaped membranous sacs inside a chloroplast. Thylakoid membranes contain chlorophyll and the enzymes of the light reactions of photosynthesis. A stack of thylakoids is called a granum.
Phospholipid bilayer membranes are semipermeable. Which of the following can move across the membrane without assistance? (ebook Module 4.2)
Oxygen and carbon dioxide can cross the phospholipid bilayer membranes.
Which of the following is the most likely consequence for a cell lacking functional lysosomes? (ebook Module 4.10)
The cell becomes crowded with undigested wastes.
cellular metabolism
The chemical activities of cells.
chromatin
The complex of DNA and proteins that constitutes eukaryotic chromosomes; often used to refer to the diffuse, very extended form taken by chromosomes when a cell is not dividing.
Where are the ribosomes that produce enzymes responsible for the first steps of sugar metabolism found? (ebook Module 4.6)
The first steps of sugar metabolism occur within the cytoplasm. Therefore, the ribosomes in the cytoplasm are responsible for making the necessary enzymes.
mitochondrial matrix
The fluid contained within the inner membrane of a mitochondrion.
stroma
The fluid of the chloroplast surrounding the thylakoid membrane; involved in the synthesis of organic molecules from carbon dioxide and water; Sugars are made in the stroma by the enzymes of the Calvin cycle.
Your intestine is lined with individual cells. No fluids leak between these cells from the gut into your body. Why? (ebook Module 4.20)
The intestinal cells are bound together by tight junctions.
plasma membrane
The membrane that sets a cell off from its surroundings and acts as a selective barrier to the passage of ions and molecules into and out of the cell; consists of a phospholipid bilayer in which are embedded molecules of protein and cholesterol.
Cell Theory
The theory that all living things are composed of cells and that all cells come from other cells.
microtubule
The thickest of the three main kinds of fibers making up the cytoskeleton of a eukaryotic cell; a straight, hollow tube made of globular proteins called tubulins. Microtubules form the basis of the structure and movement of cilia and flagella.
microfilament
The thinnest of the three main kinds of protein fibers making up the cytoskeleton of a eukaryotic cell; a solid, helical rod composed of the globular protein actin.
A certain cell has a dense nucleoid region, ribosomes, but no membrane-enclosed organelles. Based on this information, it could be _____. (ebook Module 4.3)
archaean
Peroxisomes are organelles that are involved in the _____. (ebook Module 4.12)
breakdown of fatty acids
Which of the following would be found in the cytoplasm of a eukaryotic cell? (ebook Module 4.4)
centrioles
Under a light microscope, which substance becomes visible as the cell divides? (ebook Module 4.5)
chromatin
Basal bodies are most closely associated with which of the following cell components? (ebook Module 4.17)
cilia
What are the inner folds of the mitochondria called? (ebook Module 4.13)
cristae
Where would you expect to find contractile proteins in a cell? (ebook Module 4.16)
cytoskeleton
The contractile vacuole (ebook Module 4.11)
eliminates excess water from the cytoplasm of freshwater protists
Which of the following structures is directly involved in the passage of electrical signals between cells as, for example, in the vertebrate heart? (ebook Module 4.20)
gap junctions
The maximum size of a cell is limited by _____. (ebook Module 4.2)
its need for enough surface area to make exchanges with its environment
Bacterial cells are prokaryotic; unlike a typical eukaryotic cell, they _____. (ebook Module 4.3)
lack a nucleus
Primary ciliary dyskinesia is a genetic disorder in which the cilia of the respiratory tract become immobile. As a result, these individuals suffer respiratory illnesses. This is because the cells _____. (ebook Module 4.18)
lack dynein arms
The nucleolus (Module 4.5)
manufactures ribosomes . The nucleolus, which is composed of DNA, RNA, and protein, is the site of ribosome synthesis.
The rough endoplasmic reticulum is considered to be in which general functional category of organelle? (ebook Module 4.8)
manufacturing
Mitochondria appear in the greatest numbers in cells that are _____. (ebook Module 4.13)
metabolically active
Integrins are proteins that are responsible for integrating changes that are occurring outside and inside the cell. They are able to do this because of _____. (ebook Module 4.19)
microfilaments
When elongated, tube-shaped cells from the lining of the intestine are treated with a certain chemical, the cells sag and become rounded. The internal structures disrupted by this chemical are probably _____. (ebook Module 4.16)
microtubules
The internal skeleton of a cell is composed of _____. (ebook Module 4.16)
microtubules, intermediate filaments, and microfilaments
Which of these is a function of the endomembrane system? (ebook Module 4.7)
molecule export . The endomembrane is involved in the export of molecules from the cell.
A plant cell was grown in a test tube containing radioactive nucleotides, the monomers from which DNA is built. Later examination of the cell showed the radioactivity to be concentrated in the _____. (ebook Module 4.5)
nucleus
Most of the DNA in a eukaryotic cell is in the _____. (ebook Module 4.5)
nucleus . The nucleus contains most of the genes that control the eukaryotic cell.
The general function of _____ is the breakdown of substances. (ebook Module 4.22)
peroxisomes
Chloroplasts are found in _____. (ebook Module 4.14)
plant cells and some protists . Chloroplasts are lens-shaped organelles found in leaves and other green organs of plants and photosynthetic protists.
Dye injected into a plant cell might be able to enter an adjacent cell through a(n) _____. (ebook Module 4.21)
plasmodesma
The cell junctions in plant cells that provide channels between adjacent cells are generally _____. (ebook Module 4.21)
plasmodesmata
Of the following organelles, which group is involved in manufacturing the substances needed by the cell? (ebook Module 4.8)
ribosome, rough endoplasmic reticulum, smooth endoplasmic reticulum
Which of the following are found in prokaryotic cells? (ebook Module 4.3)
ribosomes
Which of the following structures is/are found in prokaryotic cells? (ebook Module 4.3)
ribosomes
Pancreatic cells secrete lots of proteins. With this in mind, which of the following organelles would be especially abundant in pancreatic cells? (ebook Module 4.8)
rough endoplasmic reticulum
The architecture of cell surfaces can be viewed in the most detail using a _____. (ebook Module 4.1)
scanning electron microscope
You would expect a cell with an extensive Golgi apparatus to _____. (ebook Module 4.9)
secrete a lot of material
In muscle cells, the _____ is/are specialized for the storage and release of calcium. (ebook Module 4.8)
smooth endoplasmic reticulum
When isolated liver cells are combined with toxins, initial processing in the _____ increases the solubility of those compounds as an initial step in their excretion. (ebook Module 4.8)
smooth endoplasmic reticulum
What are the limits on which maximum cell size depends? (ebook Module 4.2)
surface-to-volume ratio
The term resolving power refers to _____. (ebook Module 4.1)
the clarity of the image in showing two objects as separate
Membrane proteins are synthesized by ribosomes that are attached to _____. (ebook Module 4.8)
the endoplasmic reticulum
To enter or leave any cell, substances must pass through _____. (ebook Module 4.2)
the plasma membrane