honors biology 9 chapter 7- cell structure and function

facilitated diffusion

the process of diffusion in which molecules pass across the membrane through cell membrane channels

osmosis

the diffusion of water through a selectively permeable membrane

osmotic pressure

the pressure that must be applied to prevent osmotic movement across a selectively permeable membrane

tissue

a group of similar cells that perform a particular function

cell

the basic unit of all forms of life

cell theory

a 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

nucleus

a structure that contains the cell's genetic material in the form of DNA

eukaryote

an organism whose cells contain a nucleus

prokaryote

a unicellular organism that lacks a nucleus

cytoplasm

the fluid portion of the cell outside the nucleus

organelle

a specialized structure that performs important cellular functions within a eukaryotic cell

vacuole

the cell organelle that stores materials such as water, salts, proteins, and carbohydrates

lysosome

the cell organelle that breaks down lipids, carbohydrates, and proteins into small molecules that can be used by the rest of the cell

diffusion

the process by which particles tend to move from an area where they are more concentrated to an area that has less consentration

organ

a group of tissues that work together to perform closely related functions

organ system

a group of organs that work together to perform a specific function

cytoskeleton

the network of protein filaments in a eukaryotic cell that gives the cell its shape and internal organization and is involved in movement

ribosome

a cell organelle consisting of RNA and protein found throughout the cytoplasm in a cell; the site of protein synthesis

endoplasmic reticulum

the internal membrane system found in eukaryotic cells; the place where lipid components of the cell membrane are assembled

golgi apparatus

an 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

chloroplast

an organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy

mitochondrion

a cell organelle that converts the chemical energy stored in food into compounds that are more convenient for the cell to use

lipid bilayer

a flexible double-layered sheet that makes up the cell membrane and forms a barrier between the cell and its surroundings

homeostasis

the relatively constant internal physical and chemical conditions that organisms maintain