Chapter 7 - Life Is Cellular (vocab) Flashcards
basic unit of all forms of life
cell
fundamental concept of biology that states that all living things are composed of cells; that cells are the basic units of structure and function in living things; and that new cells are produced from existing cells
cell theory
thin, flexible barrier that surrounds all cells; regulates what enters and leaves the cell
cell membrane
the center of an atom, which contains the protons and neutrons; in cells, structure that contains the cell’s genetic material in the form of DNA
nucleus
organism whose cells contain a nucleus
eukaryote
unicellular organism that lacks a nucleus
prokaryote
eukaryotic cells, all cellular contents outside the nucleus; in prokaryotic cells, all of the cells’ contents
cytoplasm
specialized structure that performs important cellular functions within a cell
organelle
cell organelle that stores materials such as water, salts, proteins, and carbohydrates
vacuole
cell organelle that breaks down lipids, carbohydrates, and proteins into small molecules that can be used by the rest of the cell
lysosome
network of protein filaments in a eukaryotic cell that gives the cell it’s shape and internal organization and is involved in movement
cytoskeleton
structure in an animal cell that helps to organize cell division
centriole
cell organelle consisting of RNA and protein found throughout the cytoplasm in a cell; the site of protein synthesis
ribosome
internal membrane system found in eukaryotic cells; place where lipid components of the cell membrane are assembled
endoplasmic reticulum
organelle in cells that modifies, sorts, and packages proteins and other materials from the endoplasmic reticulum for storage in the cell or release outside the cell
Golgi apparatus
organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy
chloroplast
cell organelle that converts the chemical energy stored in food into compounds that are more convenient for the cell to use
mitochondrion
strong, supporting layer around the cell membrane in some cells
cell wall
flexible double-layered sheet that makes up the cell membrane and forms a barrier between the cell and its surroundings
lipid bilayer
property of biological membranes that allows some substances to pass across it while others cannot; also called semipermeable membrane
selectively permeable
process by which particles tend to move from an area where they are more concentrated to an area where they are less concentrated
diffusion
process of diffusion in which molecules pass across the membrane through cell membrane channels
facilitated diffusion
water channel protein in a cell
aquaporin
diffusion of water through a selectively permeable membrane
osmosis
when the concentration of two solutions is the same
isotonic
when comparing two solutions, the solution with the greater concentration of solutes
hypertonic
when comparing two solutions, the solution with the lesser concentration of solutes
hypotonic
pressure that must be applied to prevent osmotic movement across a selectively permeable membrane
osmotic pressure
relatively constant internal physical and chemical conditions that organisms maintain
homeostasis
group of similar cells that perform a particular function
tissue
group of tissues that work together to perform closely related functions
organ
group of organs that work together to perform a specific function
organ system
on or in a cell, a specific protein to whose shape fits that of a specific molecular messenger, such as a hormone
receptor
