Andrea's Flashcards

Terms Definitions
Control center of the cell, contains all the genetic material for the cell.
Nuclear Envelope
Inner and Outer lipid bilayer separated by narrow fluid space, contains pores that allow for exchange of material nucleus and cytoplasm
are the building blocks of all living things they are not all the same but share the same structures
1 or 2 small dense bodies composed of RNA and proteins, is the site of ribosome assembly
composed of loosely coiled DNA and protein, is present when cell is not dividing
Plasma Membrane
Barrier that separates cellular from surrounding environment it is semipermeable its composed of phospholipids, proteins, cholesterol, and carbohydrates
hydrophobic tails
in the interior of the plasma membranes; hates water
hydrophilic heads
at the plasma membrane surface it likes water
protein channels and carrier molecules
permit water soluble substances to move across membrane
finger-like projections that increase surface area for absorption
extension of membrane containing microtubules they move fluid, mucus over the cell
tight junctions
membranes of cells fused together prevents material from passing through
anchoring junctions that prevent cells from being pulled apart
gap junctions
small channels between cells that allow ions and molecules to pass from one cells cytoplasm to the next cell
cytoplasm is the material outside the nucleus and inside the plasma membrane it contains cytosol, organelles, and inclusions
fluid that suspends other elements
"little organs" that perform a specific function for the cell
not essential, storage structures: glycogen, lipid droplet, pigment
"Powerhouses" of the cell specializes in aerobic respiration makes most of the bodies ATP
made up of protein and rRNA its the site of protein synthesis are free in the cytoplasm and in the RER
Rough ER
fluid filled tubules for transporting substances; studded with ribosomes and protein synthesis
smooth ER
fluid filled tubules for transporting substances; functions in lipid metabolism and detoxification of drugs and pesticides
Golgi Apparatus
stack of 6 flattened, fluid-filled membranous sacs they modifies and packages proteins received from ReR: Secretory vesicles, lysosomes, cell membrane components
membrane bound sacs that contain digestive enzymes, they digest non usable materials: foreign particles and damaged organelles
membranous sacs containing oxidase enzymes they detoxify harmful substances such as alcohol, formaldehyde, and break down free radicals
network of protein structures that extend throughout the cytoplasm it provides the cell with an internal framework; 3 elements microfilaments, intermediate filaments, microtubules
composed of actin 7nm it helps maintain cell shape support changes in cell shape and cell motility
intermediate filaments
fibrous sub units 10nm help form desmosomes
tubulin subunits 25nm hollow tubules: maintain cell shape, direct organelle movement within cell, and move chromosomes during cell division
rod shaped bodies made of microtubules direct the formation of mitotic spindle during cell division
2 or more centrioles at right angles to each other
cell diversity
cells vary in shape, size, type and number of organelles, and function structure of the cell determines function
passive transport
no energy ATP required, substance moves down its hydrostatic pressure gradient filtration; simple diffusion, osmosis, facilitated diffusion
Active transport
cell must provide ATP to energize pumps to move against concentration gradients used in endocytosis, and exocytosis
homogeneous mixture of 2 or more components
dissolving med; typically water in the body
components in smaller quantities with in solution
simple diffusion
atom molecules move from higher concentration to regions of lower concentrations until equilibrium is reached
diffusion of water across a selectively permeable membrane; water moves through lipid bilayer
facilitated diffusion
substance needs help from a membrane protein to cross the membrane, substance is not soluble in lipid bilayer
water and solutes are forced through a membrane by fluid, or hydrostatic pressure
moves materials out of the cell, material to be secreted is carried in membranous vesicle
extracellular substances are enclosed in a membranous vesicle
"cell eating" cell engulfs and takes in solid material fuses with lysosomes to digest material
"cell drinking"cell engulfs tiny droplets of liquid and dissolves molecules
Osmotic pressure
tendency of a solution pull water is directly related to concentration; high concentration greater pressure, lower concentration lower preassure
Tonicity of body cells
0.9% NaCl
Isotonic solution
has the same tonicity of the body cells; cell stays the same shape
Hypertonic solution
has a tonicity greater then body cells; it has a concentration gradient across the cell membrane so water moves out of the cell and shrinks
Hypotonic solution
has a tonicity less then body cells; it has a concentration gradient across the cell membrane so water moves into the cell and it swells
cell division all cells go through but egg or sperm, its necessary for growth and repair, product to genetically identical daughter cells that have 23 pairs of chromosomes in there nucleus
occurs in gonads, necessary for sexual reproduction, product four daughter cells, 23 chromosomes in nucleus
growth period cell grows organelles and carries on metabolic processes
Interphase: G1
cell growth number of organelles increase
Interphase: G2
cell growth more organelles
Interphase S
DNA replication occurs
DNA Replication
Composed of 2 sister chromatids held together at the centromere, sister chromatids will separate during cell division
division of the cytoplasm begins in mitosis during late anaphase resulting in 2 genetically identical daughter cells
Chromatin tightly coils forming discrete, visible chromosomes composed of sister chromatides, nuclear envelope breaks down and disappears, centrioles migrate to poles and spindle fibers forms and connect to centromeres
centromeres of all chromosomes are aligned in the center of the cell on the metaphase plate
chromatids are pulled apart and daughter chromosomes move toward opposite poles of cell and cell elongates
chromosomes uncoil to become chromatin, nuclear envelope reforms around chromatin, spindles break down and disappear and cleavage furrow forms
the segment of DNA that occurs at the ends of chromosomes and are responsible for cellular aging
Meiosis I
reduces the # of chromosomes
Meiosis II
separates the sister chromatides
pairs of structurally identical chromosomes and carry the same genes
Prophase I
Chromosomes become visible, nuclear envelope disappears, centrosomes move to the poles and form spindle fibers and some connect to centromeres, synapsis occurs and tetrads are formed and crossing over occurs and exchange genetic material
Metaphase I
each chromosome pair moves to equator and lines up at the metaphase plate
Anaphase I
homologous chromosomes move to opposite poles of the cell, and cell elongates
Telophase I
cleavage furrow forms and formation of new nuclei containing 23 chromosomes, chromosomes composed of 2 sister chroma tides uncoil, cytokinesis completed result 2 daughter cells
Prophase II
chromosomes condense, nuclear envelope disappears, centrioles migrate to the poles and spindle fibers form and some chromosomes attach
Metaphase II
centromeres of all chromosomes are aligned in the center of the cell an metaphase plate
Anaphase II
Cell elongates, centromere separates, chromatids are pulled apart and daughter chromosomes move toward opposite poles
Telophase II
Cleavage furrow forms, new nuclei for containing 23 chromosomes
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