cell theory
1)idea that all living things are composed of cells 2)cells are the basic units of structure and function in living things
3) new cells are produced from existing cells
micrographs
photographs of the view through the microscope
organelle
each cell part with a specific function
plasma membrane
defines cell border, and regulates chemicals going into and out of cell
Nucleus
A part of the cell containing DNA and RNA
Cytoplasm
area of the cell between nucleus and plasma membrane. Contains various organelles.
cell wall
protective layer around the cell membrane and maintains structure in plant cells
prokaryotic cell
a bacterial cell, has no membrane bound organelles, no nucleus
Eukaryotic cells
plant and animal cells, has nucleus enclosed by membrane
Diffusion
Movement of molecules from an area of higher concentration to an area of lower concentration.
phospholipid bilayer
a thin polar membrane made of two layers of lipid molecules. hydrophilic phosphate head and a hydrophobic tail consisting of two fatty acid chains.
Equilibrium
Concentration of molecules is equal throughout a space, system is in balance
selectively permeable membrane
a property of cell membranes that allows some substances to pass through, while others cannot
passive transport
the movement of substances across a cell membrane without the use of energy by the cell
facilitated diffusion
transport proteins provide a pathway for certain molecules to pass through membrane, including water and sugars
Osmosis
Diffusion of water through a selectively permeable membrane (passive transport)
hypertonic solution
a solution that causes a cell to shrink because of osmosis; higher concentration of solute, lower concentration of water
hypotonic solution
a solution that causes a cell to swell because of osmosis; lower concentration of solute, higher concentration of water
isotonic solution
A solution with the same concentration of water and solutes as inside a cell, resulting in the cell retaining its normal shape because there is no net movement of water.
active transport
Energy-requiring process that moves material across a cell membrane against a concentration difference
Vesicle
A membrane bound sac that contains materials involved in moving products into, out of, and throughout the cell.
Vacuole
A sac inside a cell that acts as a storage area
Exocytosis
Takes large substances out of cell by farming vesicle around it and transporting thru membrane
Endocytosis
Brings large particles inside cell by enclosing pocket in membrane and then forming a vesicle into the cell
nuclear envelope
a pair of membranes that surround the nucleus
Neucleolus
Site for ribosome assembly, found in the center of animal cell.
Endoplasmic Reticulum
continuous network if of membranes throughout the cell. Smooth and Rough ER.
Golgi apparatus
A system of membranes that modifies and packages proteins for export by the cell
Lysosome
membrane-enclosed sac of digestive enzymes; contains chemicals that break down bigger food particles so they can be used in the cell; also break down used cell parts and destroy harmful bacteria
Chloroplast
organelle found in cells of plants and some other organisms that photosynthesis takes place. Gives plants their green color.
Mitochondria
Powerhouse of the cell
Microtubules
straight, hollow tubes of proteins that give rigidity, shape, and organization to a cell
Microfilaments
thinner, solid rods of protein that enable the cell to move or change shape when protein subunits slide past one another, composed of actin subunits
Flagella
A long, whip-like filament that helps in cell motility. Many bacteria are flagellated, and sperm are flagellated.
Cilia
short, thin, numerous projections from a cell that wave in a back-and-forth motion
Photosynthesis
Conversion of light energy from the sun into chemical energy.
cellular respiration
Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen; occurs in mitochondria
ATP
(adenosine triphosphate) main energy source that cells use for most of their work
Autotroph/Producer
An organism that makes its own food
Heterotroph/ consumer
organism that obtains energy from the foods it consumes; cannot make its own food
Phagocytosis
process in which extensions of cytoplasm surround and engulf large particles and take them into the cell
Where does cellular respiration take place?
mitochondria
Robert Hooke (1665)
Studied cork and and named the structures he saw "cells".
Anton van Leeuwenhoek (1673)
First to observe living cells
Matthius Schleiden (1838)
all plants are composed of cells
Theodor Schwann (1839)
concluded that all animals are made of cells
Ruldolf Virchow (1855)
all cells come from other cells
3 classes of lipids are...
phospholipids, glycolipids, cholestoral
phospholipid structure
Each phosphate group has what charge?
Negative
Fluidity of the cell membrane
refers to viscosity of of lipid bi-layer
Homeostasis
A tendency to maintain a balanced or constant internal state
Ribosomes
Makes proteins