• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/84

Click to flip

84 Cards in this Set

  • Front
  • Back
cell theory
The unifying concept that:
1. Cells are the basic living units of organization and function in all organisms
2. All cells come from other cells.
Work by Schleiden, Schwann, and Virchow.
plasma membrane
A structurally distinctive surface membrane that surrounds all cell. By making the interior of the cell an enclosed compartment, the plasma membrane allows the chemical composition of the cell to be different from that outside the cell. (maintain homeostasis)
organelle
Internal structures that are specialized to carry out metabolic activities, such as converting energy to usable forms, synthesizing needed compounds, and manufacturing structures necessary for functioning and reproduction.
prokaryotic cell
A cell that lacks a nucleus and other membrane-enclosed organelles. Much smaller (about 1/10) the diameter of the average eukaryotic cell. The DNA is located in the nuclear area, or nucleoid.
nuclear area
Region of a prokaryotic cell that contains DNA; not enclosed by a membrane.
nucleoid
Same as nuclear area--

Region of a prokaryotic cell that contains DNA; not enclosed by a membrane.
cell wall
Extracellular structures that enclose the entire cell, including the plasma membrane. Most prokaryotic cells have these cell walls.
ribosome
Organelles that are small complexes of ribonucleic acid (RNA) and protein that synthesize polypeptides. The ribosomes of prokaryotic cells are smaller than those found in eukaryotic cells.
eukaryotic cell
An organism whose cells have nuclei and other membrane -enclosed organelles. Includes protists, fungi, plants, and animals.
cytoplasm
The part of the cell outside the nucleus.
Various organelles are suspended within the fluid component of the cytoplasm (which is called the cytosol).
cell theory
The unifying concept that:
1. Cells are the basic living units of organization and function in all organisms
2. All cells come from other cells.
Work by Schleiden, Schwann, and Virchow.
plasma membrane
A structurally distinctive surface membrane that surrounds all cell. By making the interior of the cell an enclosed compartment, the plasma membrane allows the chemical composition of the cell to be different from that outside the cell. (maintain homeostasis)
organelle
Internal structures that are specialized to carry out metabolic activities, such as converting energy to usable forms, synthesizing needed compounds, and manufacturing structures necessary for functioning and reproduction.
prokaryotic cell
A cell that lacks a nucleus and other membrane-enclosed organelles. Much smaller (about 1/10) the diameter of the average eukaryotic cell. The DNA is located in the nuclear area, or nucleoid.
nuclear area
Region of a prokaryotic cell that contains DNA; not enclosed by a membrane.

(same as nucleoid)
nucleoplasm
The part of the cell within the nucleus.
cytosol
The fluid component of the cytoplasm in which various organelles are suspended.
endomembrane system
Also known as internal membrane system--
The group of membranous structures in eukaryotic cells that interact through direct connections by vesicles; includes the endoplasmic reticulum, outer membrane of the nuclear envelope, Golgi complex, lysosomes, and the plasma membrane.
vesicle
Small, membrane-enclosed sacs formed by "budding" from the membrane of another organelle. Vesicles transport materials and also carry cargo from one organelle to another. A vesicle can form as a "bud" from the membrane of one organelle and then move to another organelle to which it fuses, thus delivering its contents into another compartment.
nucleus
1. The central region of an atom that contains the protons and neutrons. 2. A cell organelle in eukaryotes that contains the DNA and serves as the control center of the cell. 3. A mass of nerve cell bodies in the central nervous system. (Typically the the most prominent organelle in the cell).
nuclear envelope
Consists of two concentric membranes that separate the nuclear contents from the surrounding cytoplasm.
nuclear pores
Consists of protein complexes found at intervals where the membranes come together. Nuclear pores regulate the passage of materials between nucleoplasm and cytoplasm.
gene
A segment of DNA that serves as a unit of hereditary information; includes a transcribable DNA sequence (plus associated sequences regulating its transcription) that yields a protein or RNA product with a specific function.
chromosome
Structures in the cell nucleus that consist of chromatin and contain the genes. The chromosomes become visible under the microscope as distinct threadlike structures during cell division.
chromatin
The complex of DNA and protein that makes up eukaryotic chromosomes, which appears as a network of granules and strands in cells that are not dividing.
nucleolus
Specialized structure in the cell nucleus formed from regions of several chromosomes; site of assembly of the ribosomal subunits.
endoplasmic reticulum (ER)
An interconnected network of internal membranes in eukaryotic cells enclosing a compartment, the ER lumen. Rough ER has ribosomes attached to the cytosolic surface; smooth ER, a site of lipid biosynthesis, lacks ribosomes.
ER lumen
The internal space the membranes enclose.
In most cells the ER lumen forms a single internal compartment that is continuous with the compartment formed between the outer and inner membranes of the nuclear envelope.
smooth ER
The primary site for the synthesis of phospholipids and cholesterol needed to make cell membranes. Smooth ER synthesizes steroid hormones, including reproductive hormones, from cholesterol. In liver cells, smooth ER is important in enzymatically breaking down stored glycogen. The smooth ER also stores calcium ions. (lacks ribosomes)
rough ER
Outer surface is studded with ribosomes that appear as dark granules. The rough ER plays a central role in the synthesis and assembly of proteins. Many proteins that are exported from the cell (such as digestive enzymes), and those destined for other organelles, are synthesized on ribosomes bound to the ER membrane.
transport vesicle
Small cytoplasmic vesicles that move substances from one membrane system to another.
Golgi complex
(Named after Camillo Golgi)
Organelle composed of stacks of flattened, membranous sacs. Mainly responsible for modifying, packaging, and sorting proteins that will be secreted or targeted to other organelles of the internal membrane system or to the plasma membrane.
cisterna
Stacks of flattened membranous sacs that make up the Golgi complex.
cis face
(the entry surface) An area of the Golgi stack typically located nearest the nucleus and receives materials from transport vesicles bringing molecules from the ER.
trans face
(the exit surface) Is closest to the plasma membrane. It packages molecules in vesicles and transports them out of the Golgi.
medial region
The area between the cis face and the trans face, located in the Golgi stack.
lysosome
Small sacs of digestive enzymes dispersed in the cytoplasm of most animal cells.
Because lysosomal are active under rather acidic condition, the lysosome maintains a pH of about 5 in its interior. (However, beware of "leaky" lysosomes).
primary lysosome
Formed by budding from the Golgi complex. Their hydrolytic enzymes are synthesized in the rough ER. As these enzymes pass through the lumen of the ER, sugars attach to each molecule, identifying it as bound for a lysosome. This signal permits the Golgi complex to sort the enzyme to the lysosomes rather than to export it from the cell.
secondary lysosome
A larger vesicle (than the primary lysosome) which is formed when one or more primary lysosomes fuse with the vesicle containing the ingested material. Powerful enzymes in the secondary lysosome come in contact with the ingested molecules and degrade them into their components. Sometimes, lysosomes break down organelles and allow their components to be recycled or used as an energy source.
peroxisome
Membrane-enclosed organelles containing enzymes that catalyze an assortment of metabolic reactions in which hydrogen is transferred from various compounds to oxygen. During these oxidation reactions, they produce hydrogen peroxide. They break down fatty acid molecules and synthesize certain phospholipids. In humans, they detoxify certain toxic compounds.
glyoxysomes
Specialized peroxisomes found in plant seeds containing enzymes that convert stored fats to sugars. The sugars are used by the young plant as an energy source and as a component for synthesizing other compounds.
Animal cells lack glyoxysomes and cannot convert fatty acids into sugars.
vacuole
A fluid-filled, membrane-enclosed sac found within the cytoplasm; may function in storage, digestion, or water elimination.
tonoplast
The membrane surrounding a vacuole.
food vacuole
Fuse with lysosomes that digest the food. Most protozoa have food vacuoles.
contractile vacuole
Removes excess water from the cells.

Some protozoa have these contractile vacuoles.
mitochondrion
Intracellular organelles that are the sites of aerobic respiration, an oxygen-requiring process that includes most of the reactions that convert the chemical energy present in certain foods to ATP. Virtually all eukaryotic cells (plant, animal, fungal, and protist) contain these organelles; includes an outer membrane and an inner membrane.
endosymbiont theory
Endosymbiont means: An organism that lives inside the body of another kind of organism. Endosymbionts may benefit their host (mutualism) or harm their host (parasitism).
aerobic respiration
An oxygen-requiring process that includes most of the reactions that convert the chemical energy present in certain foods to ATP. During aerobic respiration, carbon and oxygen atoms are removed from food molecules, such as glucose, and converted to carbon dioxide and water.
cristae
The folds, found in the inner mitochondrial membrane, extend into the matrix. Cristae greatly increase the surface area of the inner mitochondrial membrane, providing a surface for the chemical reactions that transform the chemical energy in food molecules into the energy of ATP.
mitochondrial matrix
The interior of the compartment enclosed by the inner mitochondrial membrane.
chloroplast
Membranous organelles that are the sites of photosynthesis in eukaryotes; occur in some plant and algal cells.
photosynthesis
The biological process that captures light energy and transforms it into the chemical energy of organic molecules (e.g., carbohydrates), which are manufactured from carbon dioxide and water.
stroma
A fluid space of the chloroplast, enclosed by the chloroplast inner membrane and surrounding the thylakoids; site of the reaction of the Calvin cycle.
thylakoid
An interconnected system of flattened, saclike, membranous structures inside the chloroplast.
grana
The stacks of thylakoids.
plastids
A family of membrane-enclosed organelles occurring in photosynthetic eukaryotic cells; include chloroplasts, chromoplasts, and amyloplasts and other leukoplasts.
proplastid
Organelles that are plastid precursors; may mature into various specialized plastids, including chloroplasts, chromoplasts, or leukoplasts.
chromoplast
Pigment-containing plastids that give certain flowers and fruits their characteristic colors.
leukoplast
Unpigmented plastids; include amyloplasts, which are used for starch storage in cells of roots and tubers.
amyloplast
Unpigmented plastids; which are used for starch storage in cells of roots and tubers. (like a leukoplast)
cytoskeleton
A dense network of protein fibers that includes microfilaments, intermediate filaments, and microtubules. It gives cells mechanical strength, shape, and their ability to move. The cytoskeleton also functions in cell division and in the transport of materials within the cell.
microtubule
The thickest filaments of the cytoskeleton, are rigid, hollow, cylindrical fibers consisting of tubulin protein subunits; major structural components of the cytoskeleton and are also involved in the movement of chromosomes during cell division. Found in mitotic spindles, cilia, flagella, centrioles, and basal bodies.
tubulin dimer
A microtubule elongates by the addition of tubulin dimers. Microtubules are disassembled by the removal of dimers, which are recycled to form new microtubules.
MAP
microtubule-associated proteins
Proteins important in microtubule function. Classified into two groups; structural MAPs may help regulate microtubule assembly, and they cross-link microtubules, and motor MAPs which use ATP energy to produce movement.
MTOC
microtubule-organizing centers
The region of the cell from which microtubules are anchored, and possibly assembled. The MTOCs of many organisms (including animals, but not flowering plants or most gymnosperms) contain a pair of centrioles.
centrosomes
An organelle in animal cells that is the main microtubule-organizing center; typically contains a pair of centrioles and is important in cell division.
centriole
One of a pair of small, cylindrical organelles lying at right angles to each other near the nucleus in the cytoplasm of animal cells and certain protist and plant cells; each centriole is in the form of a cylinder composed of nine triplets of microtubules.

(Also known as 9x3 structure)
kinesin
A motor protein that moves organelles toward the plus end of a microtubule.
dynein
A motor protein that transports organelles in the opposite direction, toward the minus end of a microtubule.
9+2
Refers to the arrangement of a group of microtubules arranged so there are nine attached pairs of microtubules around the circumference and two unpaired microtubules in the center. This 9+2 arrangement of microtubules is characteristic of virtually all eukaryotic cilia and flagella.
basal body
Structure involved in the organization and anchorage of a cilium or flagellum. Structurally similar to a centriole; each is in the form of a cylinder composed of nine triplets of microtubules (9x3 structure).
microfilament
Flexible, solid fibers consisting of two intertwined polymer chains of beadlike actin molecules. They provide mechanical support for various cell structures.
actin
The protein of which microfilaments consist. Actin, together with the protein myosin, is responsible for muscle contraction.
intermediate filament
Tough, flexible fibers that provide mechanical strength and help stabilize cell shape. Intermediate filaments prevent the cell from stretching excessively in response to outside forces. All eukaryotic cells, but only some animal groups, including vertebrates, are known to have intermediate filaments.
glycocalyx
A coating on the outside of an animal cell, formed by the polysaccaride portions of glycoproteins and glycolipids, associated with the plasma membrane.
ECM
extracellular matrix
A network of proteins and carbohydrates that surrounds many animal cells.
collagen
Proteins found in the collagen fibers of connective tissues.
fibronectins
Certain glycoproteins of the ECM that help organize the matrix and help cells attach to it. Fibronectins bind to protein receptors that extend from the plasma membrane.
integrins
Proteins that serve as membrane receptors for the ECM. These proteins activate many cell signaling pathways that communicate info from the ECM. Integrins may be important in cell movement and in organizing the cytoskeleton so that cells assume a definite shape.
cell signaling
Mechanisms of communication between cells. Cells signal one another with secreted signaling molecules, or a signaling molecule on one cell combines with a receptor on another cell.
cellulose
A structural polysaccharide consisting of beta glucose subunits; the main constituent of plant primary cell walls.
middle lamella
A layer of gluelike polysaccharides that serve to cement together the primary cell walls of adjacent plant cells.
primary cell wall
Thin, flexible cell wall which a growing plant cell will secrete. This primary cell wall increases in size as it the cell grows.
After the cell stops growing, either new wall material is secreted that thickens and solidifies the primary wall or multiple layers of a secondary cell wall are then formed.
secondary cell wall
Formed between the primary wall and the plasma membrane.

A plant cell that has stopped growing can secrete this secondary cell wall (with a different chemical composition than that of the primary wall).