Chapter 3: The Cell vocab

cell

the basic unit of all life

Cell theory

1) All organisms are composed of cells; 2) Cells are the basic units of structure and function in organisms; 3) Cells come only from pre-existing cells because cells are self-reproducing

Prokaryotic cells

cells that lack a membrane-bound nucleus

Eukaryotic cells

cells with a nucleus and internal membrane-bound organelles

Endosymbiotic Theory

the idea that many organelles resulted from prokaryotic organisms being engulfed by larger cells

Organelles

One of the small bodies that are found in the cytoplasm of the cell and that are specialized to perform a specific function

ribosomes

tiny protein factories

nucleus

holder + protector of DNA

Endoplasmic Reticulum

network of channels for materials to travel through

Golgi Apparatus: editing center for cellular products

cytoplasm

gel-like fluid that fills in the space between organelles

cell wall

surrounds the cell and gives it support + protection

cell membrane

surrounds cell, determines what can enter + exit

Passive Transport

Movement of substances across the membrane that does NOT require energy

Active transport

Movement of substances across the membrane that DOES require energy

Concentration Gradient

When one area has a higher concentration than another area does

Diffusion

Movement of substances from an area of higher concentration to an area of lower concentration

Simple Diffusion

Small, nonpolar molecules passing directly through the lipid bilayer

Facilitated Diffusion

Transport proteins helping substances diffuse through the cell membrane

Pump

Transport proteins that require energy to “pump” substances against their concentration gradient

Endocytosis

The movement of a large substance INTO a cell by means of a vesicle

Exocytosis

The movement of a large substance OUT of a cell by means of a vesicle

Homeostasis

The maintenance of stable internal conditions in a changing environment

Osmosis

the diffusion of water across a selectively permeable membrane

Hypertonic Solution

When there is a higher concentration of solute OUTSIDE of the cell

Hypotonic Solution

When there is a higher concentration of solute INSIDE of the cell

Isotonic Solution

When there is the same concentration of solute inside and outside of the cell

Vacuole

stores water, food, waste, etc depending on the organism

Lysosome

breaks down waste, food, or unwanted cell parts

Chloroplast

makes sugar (food) using light energy, CO2, + water

Mitochondria

makes energy using sugar and O2