Chapter 8 vocab

Miller and Levine Biology Book

Cell

Basic unit of all forms of life

Cell theory

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 membrane

Thin, flexible barrier that surrounds all cells; regulates what enters and leaves the cell

Nucleus

In cells, structure that contains the cell’s genetic material in the form of DNA

Eukaryote

Organism whose cells contain a nucleus

Prokaryote

Unicellular organism that lacks a nucleus

Cytoplasm

Fluid portion of the cell outside the nucleus

Organelle

Specialized structure that performs important cellular functions within a eukaryotic cell

Ribosome

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

Endoplasmic reticulum

Internal membrane system found in eukaryotic cells; placed where lipid components of the cell membrane are assembled

Golgi apparatus

Organelle in cells that modifies, sorts, and packages proteins and other materials from the endoplasmic reticulum for storage in the cell or released outside the cell

Vacuole

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

Lysosome

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

Cytoskeleton

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

Chloroplast

Organelle found in cells of plants and some other organisms that capture energy from the sunlight and converts it into chemical energy

Mitochondrion

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

Cell wall

Strong supporting layer around the cell membrane and some cells

Lipid bilayer

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

Selectively permeable

Property of biological membranes that allows some substances to pass across it while others cannot, also called semi-permeable membrane

Homeostasis

Relatively consistent internal physical and chemical conditions that organisms maintain

Diffusion

Process by which particles tend to move from an area where they are more concentrated to an area where there are less concentrated

Facilitated diffusion

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

Aquaporin

Water channel protein in a cell

Isotonic

When the concentration of two solutions is the same

Hypertonic

When comparing two solutions, the solution with the greater concentration of solutes

Hypotonic

When comparing two solutions, the solution with the lesser concentration of solutes

Osmotic pressure

Pressure that must be applied to prevent osmotic movement across a selectively

Tissue

Group of similar cells that perform a particular function

Organ

Group of tissues that work together to perform closely related functions

Organ system

Group of organs that work together to perform a specific function

Receptor

On or in a cell, a specific protein to whose shape fits that of a specific molecular messenger, such as a hormone