Bio 11 Cell Structure and Function
carrier proteins
carry molecules that cannot pass through the cell membrane because they are too large or insoluble
thylakoids
A flattened membrane sac inside the chloroplast, used to convert light energy to chemical energy.
smooth endoplasmic reticulum
An endomembrane system where lipids are synthesized, calcium levels are regulated, and toxic substances are broken down.
polyribosomes
Found in eukaryotic and prokaryotic cells, enable a cell to make many copies of a polypeptide very quickly during translation; multiple ribosomes attached to an MRNA strand
centrioles
One of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope; play a role in cell division.
prokaryotic cells
Small, simple, no nucleus, no membrane-bound organelles, single loop of DNA (nucleosome), no cellulose, cytoplasm, cell membrane, cell wall (made of carbs), somtimes have cilia or flagella (movement).
rough endoplasmic reticulum
System of internal membranes within the cytoplasm. Membranes are rough due to the presence of ribosomes. functions in transport of substances such as proteins within the cytoplasm
fluid mosaic model
The currently accepted model of cell membrane structure, which envisions the membrane as a mosaic of individually inserted protein molecules drifting laterally in a fluid bilayer of phospholipids.
cytoplasm
The region of the cell between the cell membrane and the nucleus
plasmids
The smalll, circular segments of DNA that are found in bacteria and that stay sparate from the bacterial chromosomes; used in genetic engineering.
secretion
a functionally specialized substance (especially one that is not a waste) released from a gland or cell
Golgi apparatus
a net-like structure in the cytoplasm of animal cells (especially in those cells that produce secretions)
Nucleus
a part of the cell containing DNA and RNA and responsible for growth and reproduction
receptor protein
a protein that binds specific signal molecules, which causes the cell to respond
Plasma membrane
a thin membrane around the cytoplasm of a cell, thin outer boundary of a cell that regulates the traffic of chemicals between the cell and its surroundings
vacuole
a tiny cavity filled with fluid in the cytoplasm of a cell
endoplasmic reticulum
an internal membrane system in which components of cell membrane and some proteins are constructed
Glycolipids
carbohydrates covalently bonded to lipids
ribosomes
non membrane bounded organelles responsible for protein synthesis (make proteins)
motor molecules
proteins with energy from ATP that propel themselves along a protein filament. is bound to a vesicle, and carries the vesicle somewhere
cilia
short structures projecting from a cell and containing bundles of microtubules that move a cell through its surroundings or move fluid over the cell's surface
stroma
the supporting tissue of an organ (as opposed to parenchyma)
chromosomes
threadlike structures made of DNA molecules that contain the genes
bacteria
(microbiology) single-celled or noncellular spherical or spiral or rod-shaped organisms lacking chlorophyll that reproduce by fission
nucleoid
A dense region of DNA in a prokaryotic cell.
slime layer
A thin protective structure loosely bound to the cell wall that protects the cell against drying, helps trap nutrients, and sometimes binds cells together
Lysosomes
An organelle containing digestive enzymes
endosymbiotic hypothesis
Explanation of the origin of eukaryotic cells. Mitochondria and chloroplasts were one free living cells that became engulfed in another cell.
cristae
Infoldings of the inner membrane of a mitochondrion that houses the electon transport chain and the enzyme catalyzing the synthesis of ATP.
Peripheral proteins
Protein appendages loosely bound to the surface of the membrane and not embedded in the lipid bilayer.
nucleoplasm
The fluid contained within the nucleus of a eukaryote in which the chromosomes and nucleoli are found.
nucleolus
The organelle where ribosomes are made, synthesized and partially assembled, located in the nucleus
flagellum
a lash-like appendage used for locomotion (e.g., in sperm cells and some bacteria and protozoa)
capsule
a pill in the form of a small rounded gelatinous container with medicine inside
cell wall
a thin membrane around the cytoplasm of a cell
mitochondrion
an organelle containing enzymes responsible for producing energy
microtubules
hollow tubes of protein about 25 nanometers in diameter, support the cell and moves organelles within the cell
Peroxisomes
membranous sacs containing enzymes used to break down hydrogen peroxide
matrix
mold used in the production of phonograph records, type, or other relief surface
cytoskeleton
network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement
Chloroplasts
organelles that capture the energy from sunlight and convert it into chemical energy in a process called photosynthesis
Integeral proteins
penetraits both layers of the cell membrane
glycoproteins
proteins that have carbohydrates covalently bonded to them
channel proteins
proteins that provide passageways through the membrane for certain hydrophilic (water-soluble) substances such as polar and charged molecules
enzymatic proteins
selective acceleration of chemical reactions
vesicles
small membrane sacs that specialize in moving products into, out of, and within a cell
centrosome
small region of cytoplasm adjacent to the nucleus
nuclear pores
structures in the nuclear envelope that allow passage of certain materials between the cell nucleus and the cytoplasm
Chromatin
the readily stainable substance of a cell nucleus consisting of DNA and RNA and various proteins
organelles
tiny structures that carry out functions necessary for the cell to stay alive
flagella
whiplike tails found in one-celled organisms to aid in movement
nuclear envelope
A double membrane that surrounds the nucleus in the cell
Cholesterol
an animal sterol that is normally synthesized by the liver
