Question | Answer |
the study of cellular structure and function | cytology |
aspects of biology, chemistry, and physics | cell biology |
___________ also called germ cells or reproductive cells, male sperm, female oocyte (a cell that develops into an egg) | sex cells |
all body cells except sex cells | somatic cells |
each cell is surrounded by_______, outer body of the cell, largest membrane of the cell | plasma membrane |
exhibits the most important characteristics of many cell types, no one cell looks exactly the same | composite cell |
3 main structures of the composite cell | cell membrane, cytoplasm with organelles, nucleus |
_______ is general term for the material located between the plasma membrane and the membrane surrounding the nucleus, gel-like substance inside cells | cytoplasm |
at the center of the cell is the _______, not considered part of the cytoplasm, holds DNA | nucleus |
________being the primary component of the plasma membrane | phospholipid |
current model of how membranes are constructed, molecules are arranged in a sheet, molecules are fluid (able to slowly float around like icebergs) | fluid mosaic model |
what holds membranes together | chemical attraction |
water loving heads | hydrophilic |
water hating tails | hydrophobic |
arranged into two layers | bilayer |
T/F heads point to watery enviroment in and outside of the cell | true |
T/F tails point toward each other, away from the water | true |
mixed in between 2 layers of phospholipids, forms blend of lipids that is just fluid enough to function properly at body temperature, membranes would be weak without _________ (acts as a stabilizer to prevent breakage) | cholesterol |
a cell uses ________ to control what goes in and out | membrane proteins |
carbohydrates attached to proteins | glycoprotein |
"carry across" carrying a message across the membrane | signal transduction |
watery substance, intracellular fluid, contains dissolved nutrients, ions, soluble and insoluble proteins, and waste | cytosol |
"little organs" that thicken the cytoplasm, structures suspended within the cytosol that perform specific functions for the cell | organelles |
2 main groups of organelles | membranous, nonmembranous |
specialized sacs or canals made of cell membrane | membranous |
_________ are not made of membrane, microscopic filaments and other ________ materials | nonmembranous |
cell's internal supporting framework, made up of rigid, rod-like pieces, provides support and allow movement, has muscle-like groups of fibers, move the cell or parts of the cell | cytoskeleton |
______form a 3d, irregularity shapped lattice (like scaffolding in the cell), supports part of the cell (organelles attach to these, do not float free in the cytoplasm) | cell fibers |
smallest of these fibers, "cellular muscles", thin and twisted strands of protein (form bundles that lie parallel to the long axis of the cell), in some cells these fibers can slide past each other, shortens the cell, muscle cells | microfilaments |
twisted protein strands, slightly thicker than microfilaments, form much of the supporting framework of cells (protective cells in outer layer of skin filled with dense arrangement of these filaments | intermediate filaments |
thickestof the cell fibers, protein subunits arranged in spiral fashion, "engines of the cell" (often moves things around the cell, can cause movement of the entire cell) moving vesicles around the cell and separation of chromosones during the cell div | microtubules |
area of the cytoskeleton (very active, requires coordination of many functional proteins, near the nucleus, heart of the cytoskeleton | centrosome |
pair of cylindrical structures within the centrosome, walls consist of 9 bundles of microtubules (3 in each bundle) | centrioles |
how do vesicles and organelles move around the cell in an organized way? | Cell has internal "feet" mafe of protein structures |
pull huge loads along microtubules and microfilaments of the cytoskeleton (vesicles, small organelles, fibers, large molecules) | molecular motors |
found in epithelial cells that line the intestines (other areas where absorption is important), crowd and cover part of the cell surface, microfilaments bundles are inside each extension(structural support and movement), increases surface area of the cell | microvilli |
have cylinders made of microtubules at their core (9 double microtubules around 2 single microtubules in the center), different from the centriole's arrangement, this arrangement is suited for movement | cilia and flagella |
shorter and more mnumerous, look like tiny hairs, in respiratory tract (keep contaminated mucous moving toward throat), in female reproductive tract(keep ovum moving towards uterus) | cilia |
simple, long structures, found in sperm (allow them to swim toward the ovum | flagella |
many cells attach directly to the __________ | extracellular matrix |
attached via proteins called_________some span the plasma membrane connecting fibers of cytoskeleton to matrix | intergrin |
cytoplasm located toward the center of the cell | endoplasm |
network-literally is a network located deep in the cytoplasm | reticulum |
2 types of Edoplasmic reticulum | rough and smooth |
covered with ribosomes, give it a ______ apperance | rough |
does not have ribosomes on its surface, has a ______ apperance | smooth |
rough ER functions | protein synthesis, intracellular transportation |
ribosomes on the surface make proteins, these proteins enter the ER, transported through the ER toward the Golgi, from the Golgi, they eventually leave the cell | rough er |
lack ribosomes, functions are less established and most likely more varied, synthesize lipids of the cell membrance, cholesterol is made here | smooth er |
1000's in every cell, many are attached to the rough ER, the rest lie free in the cytoplasm, tiny organelles, nonmembraneous organelle, composed of 2 subunits | ribosomes |
ribosomes function | protein synthesis |
working ribosomes appear in groups, they look like short strings of beads | polyribosomes |
membranous organelle, made of cisternae (tiny sacs stacked on one another), located near the nucleus | golgi apparatus |
golgi apparatus funtion: | it processes molecules |
membranous bubbles | vesicles |
membranous organelles, vesicles that have pinched off from the golgi, size & shape depends on their stage of activity, contain various enzymes, can destroy several things at a time, "digestive bag or cellular garbage disposal" | lysosomes |
protein-destoyer, nonmembranous organelle, hollow-cylindrical shape (made of protein subunits) only capable of destroying one protein at a time, | proteasome |
membranous organelle, sac-like structure, contains enzymes, detoxify hramful substances that can enter cells, often seen in kidney and liver cells, peroxidase and catalase | peroxisomes |
membranous organelle, high complex and organized molecular structure, walls have 3 membranes (form a sac withing a sac), inner membrane folded into cristae, "power plants" of the cell | mitochondria |
one of the largest cellular structures, occupies central portion, shape and number vary, membranous structure, 2 membranes perforated by pores | nucleus |
enclose the nucleoplasm | nucleus cytoplasm |
intricate structures, often called NPC's, selectively permit molecules to enter or leave the nucleus | nuclear pores |
collective name for the 2 nuclear membranes, same molecular structure as other membranes, extensions of the ER walls | nuclear envelope |
most important fact to remember about the nucleus: | contains DNA: heredity molecules |
in nondividing cells, appear thread-like | chromatin |
during cell division, become tightly coiled and look like short rods | chromosomes |
all normal human cells contain ______ | 46 chromosomes |
mature sex cells have _______ | 23 chromosomes |
most noticeable structure in the nucleus, nonmembranous, contain RNA, synthesis ribosomal RNA (rRNA) | nucleolus |