Chapter 2- Introduction to Cells Flashcards
Define microscope.
an instrument that makes small objects look larger
Define cell.
form the parts of an organism and carry out all of its functions
Define cell theory.
a widely accepted explanation of the relationship between cells and living things
Define organelles.
tiny structures in cells that each have a specific function
Define cell wall.
a rigid layer that surround the cells of plants and some other organisms
Define cell membrane.
controls which substances pass in and out of a cell
Define nucleus.
acts as cell’s control center, directing all of the cell’s activities
Define organelles.
tiny cell structures that carry out specific functions in a cell
Define ribosomes.
small, grain-shaped organelles that produce proteins
Define cytoplasm.
fills the region between the cell membrane and the nucleus
Define mitochondria.
convert energy stored in food to energy the cell can use to live and function
Define endoplasmic reticulum.
ER, an organelle which a network of membranes that produce many substances
Define Golgi apparatus.
receives proteins and other newly formed materials from the ER, packages them, and distributes them to other parts of the cell or to the outside of the cell
Define vacuole.
stores water, food, and other materials needed by the cell
Define chloroplast.
captures energy from sunlight and changes it to a form of energy cells can use in making cells
Define lysosomes.
saclike organelles which contains substances that break down large food particles into smaller ones
Define multicellular.
made of many cells
Define unicellular.
single-celled
Define tissue.
a group of similar cells that work together to perform a specific function
Define organ.
made of different kinds of tissues that function together
Define organ system.
a group of organs that work together to perform a major function
Define elements.
any substance that cannot be broken down
Define compounds.
form when 2 or more elements combine chemically
Define carboyhdrates.
energy-rich organic compounds made of the elements carbon, hydrogen, and oxygen
Define lipids.
compounds made mostly of carbon, hydrogen, and some oxygen
Define proteins.
large organic molecules made of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur
Define enzymes.
speed up chemical reactions in living things
Define nucleic acids.
very long organic molecules
Define DNA.
the genetic material that carries information about an organism and is passed from parent to offspring
Define double helix.
the shape of a DNA molecule
