BIOL 1406 FLASHCARDS: Exam #2

The smallest unit of life that can function independently

All organisms are made up of one or more cells

The cell is the fundamental unit of life

All cells come from preexisting cells

All cells have the same basic chemical composition

All cells use energy

All cells contain DNA that is duplicated and passed on as each cell divides

Contain genetic material

Contain ribosomes

Contain cytoplasm

Have a cell membrane

Carry out chemical reactions needed to sustain life, such as cellular respiration and protein synthesis

Nuclear membrane is absent so they do not have a distinct nucleus

They do not have many of the membrane-bound structures

DNA is free in its naked form

Examples include bacteria, cyanobacteria, and archaebacteria

A double nuclear membrane is present, so they have distinct nuclei

They have membrane bound structures

DNA is packaged in chromosomes

Examples include algae, fungi, animals, and plants

The ratio of the size of an image to the size of the object

The clarity of a magnified object; the minimum distance two objects can be apart and still be seen as two distinct objects

Used to view the entire cell

Used to view the parts of cells, and viruses, which are smaller and require higher magnification

Light passes directly through the cell

Contrast in the image is increased by emphasizing differences in the refractive index, thereby enhancing the light and dark regions of the cell

Uses two beams of polarized light - the combined images look as if the cell is casting a shadow on one side

A stain enhances contrast and reveals details of the cell that would otherwise not be visible; the stains differ greatly in their chemistry and in their capacity to bind to cell materials, so many choices are available

A natural substance in the cell or a fluorescent dye that binds to a specific cell material is stimulated by a beam of light, and the longer-wavelength fluorescent light is observed coming directly from the dye

A beam of electrons is focused on the cell by magnets; objects appear darker if they absorb the electrons; if the electrons pass through, they are detected on a fluorescent screen

Directs electrons to the surface of the cell sample, where they cause other electrons to be emitted; these electrons are then viewed on a screen where the three-dimensional surface of the sample can be visualized

A slender threadlike structure, especially a microscopic appendage that enables many protozoa, bacteria, spermatozoa, etc. to swim

Short, hair-like structures on the cell surface of prokaryotic cells

A short microscopic hairlike vibrating structure found in large numbers on the surface of certain cells; either causes currents in the surrounding fluid, or, in some protozoans and other small organisms, provides propulsion

An appendage of a male bacterium by which it attaches to a female bacterium, preparatory to the transfer of DNA from male to female

A small, circular, double-stranded DNA molecule that is distinct from a cell's chromosomal DNA

A chromatin-dense area within the cytoplasm of prokaryotic cells; contains bacterial DNA, associated proteins, and RNA responsible for controlling bacterial activity and reproduction

Protective container for the cell’s DNA; DNA never leaves this structure, but messages (mRNA) can be sent to other parts of the cell

An area inside the nucleus of a cell that is made up of RNA and proteins and is where ribosomes are made

A highly regulated double membranous barrier that separates the nucleus from the cytoplasm in eukaryotic cells

Allow for the movement of specific molecules between the nucleus and cytoplasm

Builds proteins by piecing together long chains of amino acids according to mRNA messages (copies of pieces of DNA)

Plastid containing chlorophyll and other pigments; in plants that carry out photosynthesis

A pigment that gives plants their green color; helps plants create their own food through photosynthesis

The site of photochemical or light-dependent reactions of photosynthesis in chloroplasts

One of the lamellar stacks of chlorophyll-containing thylakoids found in plant chloroplasts

The fluid-filled internal space of the chloroplasts which encircle the grana and the thylakoids

Found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur; it has a double membrane, the inner layer being folded inward to form layers

Each of the partial partitions in a mitochondrion formed by infolding of the inner membrane

The mitochondrion internal spaces enclosed by the inner membrane

States that some of the organelles (such as mitochondria and chloroplasts) in eukaryotic cells were once prokaryotic microbes

A thin membrane enclosing the cytoplasm of a cell; proteins in the membrane control passage of ions in and out of the cell

A rigid layer of polysaccharides enclosing the membrane of plant and prokaryotic cells; contain peptidoglycan in bacteria

The protoplasm of a cell excluding the nucleus; is full of proteins that control cell metabolism

Receives products from the ER and adds final modifications; it also sorts these products and sends them to their final destinations; in plants, polysaccharides used in the production of cell walls are synthesized here

A membrane-enclosed bag of digestive juices; breaks down large molecules and old cell parts into their components which can be recycled to build new cell parts

Originate from the Golgi body

A product of phagocytosis - during phagocytosis, a phagosome is formed, which fuses with a primary lysosome in order to form this

Collect and break down toxic byproducts of metabolic reactions, such as hydrogen peroxide, using specialized enzymes

Convert lipids into carbohydrates which are used for cellular growth

Large folded membrane system studded with ribosomes; ribosomes build proteins and this structure helps to fold or modify them; products made here are sent to the Golgi body

Large folded membrane system; pieces together lipids and plays an important role in the production of new membranes

System of protein filaments that maintain cell shape and play roles in cell movement and cell division

Filament of tubulin monomers, 25 nm in diameter; play an important role in cell structure, organization, mitosis, and movement

Cytoskeletal filament, 8-12 nm in diameter; structural protein in eukaryotic cell

Polymer of actin monomers, 7 nm in diameter, globular protein arranged in a helix; major contractile component of muscle cells

Intercellular pores connecting adjacent plant cells allowing membrane and cytoplasmic continuity; essential routes for intercellular trafficking, communication, and signaling in plant development and defense

Large vesicles derived from the ER and Golgi body; diverse maintenance compartments

Large, membrane-bound organelles found in plant cells that act as a storage space for water and other molecules in the cell

A vacuole with a digestive function in the protoplasm of a protozoan

A vacuole in some protozoans which expels excess liquid on contraction

A colorless organelle found in plant cells, used for the storage of starch or oil

A threadlike structure of nucleic acids and proteins found in the nucleus of most living cells; carries genetic information in the form of genes; composed of long, thin strands of chromatin

The material of which the chromosomes of organisms other than bacteria (i.e., eukaryotes) are composed; consists of protein, RNA, and DNA

Process in which phagocytes engulf and digest microorganisms and cellular debris; "cellular eating"

Process by which certain cells can engulf and incorporate droplets of fluid; "cellular drinking"

The process of vesicles fusing with the plasma membrane and releasing their contents to the outside of the cell

The process of capturing a substance or particle from outside the cell by engulfing it with the cell membrane, and bringing it into the cell

A process by which cells absorb metabolites, hormones, proteins – and in some cases viruses – by the inward budding of the plasma membrane (invagination)

Composed of fibrous proteins such as collagen, gel-like proteoglycans, and other proteins; holds cells together in tissues, contributes to properties of bone, cartilage, skin, etc., filters materials passing between different tissues, orients cell movements in development and tissue repair, and plays an important role in chemical signaling

Refers to the cell membrane's ability to differentiate between different types of molecules, only allowing some molecules through while blocking others

Describes the cell membrane as a tapestry of several types of molecules (phospholipids, cholesterols, and proteins) that are constantly moving

The most abundant lipids in the plasma membrane; amphipathic molecules, containing hydrophobic and hydrophilic regions and varying in fatty acid chain length, degree of saturation, and phosphate groups

A class of membrane proteins that attach to the lipid bilayer, acting on the lipid-water interface

A class of membrane proteins that are permanently embedded within the plasma membrane; they serve a range of important functions, including transport, enzymatic activity, signal transduction, cell-cell recognition, intercellular joining, and attachment to the cytoskeleton and extracellular matrix

Integral membrane proteins that serve as channels in the transfer of water, and in some cases, small solutes across the membrane

A type of integral membrane protein that spans the entirety of the cell membrane

A carbohydrate that is covalently linked to a lipid

A carbohydrate that is covalently linked to a protein

Intercellular connections between the plasma membranes of adjacent cells

Help ensure directional movement of materials; the proteins of these cell junctions form a “quilted seal”, barring the movement of dissolved materials through the space between epithelial cells

Mimic “spot welds”; link adjacent cells together tightly, but permit materials to move around them in the intercellular space

Allow for communication between adjacent cells

A type of cellular transport in which substances such as ions and molecules move down their respective concentration gradients; does not require energy

The net passive movement of molecules or particles from regions of higher to regions of lower concentration

A form of diffusion that does not require the assistance of membrane proteins

The diffusion of water across a selectively permeable membrane

The maintenance of constant osmotic pressure in the fluids of an organism by the control of water and salt concentrations

Allow for the passage of hydrophilic substances across a cell membrane

The diffusion of solutes through transport proteins in the plasma membrane

Occurs when the concentration of particles is higher in one area than another

A type of cellular transport in which substances such as ions and molecules move against their respective concentration gradients; requires energy

The transport of molecules against a concentration gradient by the use of energy from ATP

The transport of two different molecules across a transport membrane using energy in other forms than ATP

The capability of a solution to modify the volume of cells by altering their water content

Any external solution that has the same solute concentration and water concentration compared to body fluids; no net movement of water will take place

Any external solution that has a low solute concentration and high water concentration compared to body fluids; the net movement of water will be into the body and out of the solution

Any external solution that has a high solute concentration and low water concentration compared to body fluids; the net movement of water will be out of the body and into the solution

Refers to the state of being turgid or swollen due to high fluid content inside the cell

Refers to the state between turgidity and plasmolysis in which the plasma membrane is not pushed against the cell wall

The process of contraction or shrinkage of the protoplasm of a plant cell and is caused due to the loss of water in the cell

A protein pump found in the cell membrane of neurons (and other animal cells); acts to transport sodium and potassium ions across the cell membrane in a ratio of 3 sodium ions out for every 2 potassium ions brought in

A membrane transport protein that transports a single species of substrate (charged or uncharged) across a cell membrane

An integral membrane protein that is involved in the transport of two different molecules across the cell membrane in the same direction