Unit 2 Cell Processes

Active Transport

The movement of substances across a cell membrane that requires the use of energy.

ATP

Adenosine triphosphate (ATP) is a molecule that is the source of energy for use and storage in cells

Cell Cycle

A series of events that takes place in a cell as it grows and divides

Cellular Respiration

The process by which cells break down glucose and other organic molecules to release energy.

Cytokenesis

The cytoplasmic division of a cell at the end of mitosis or meiosis, bringing about the separation into two daughter cells.

DNA

Molecule present in all living things; contains the genetic information that determines the traits that an organism inherits and needs to live

S. Diffusion

The process by which molecules move from an area of higher concentration to an area of lower concentration.

Endocytosis

The process by which cells engulf external substances by forming a vesicle around them.

Exocytosis

The process by which cells release substances from inside the cell to the outside.

Facilitated Diffusion

The movement of specific molecules across a cell membrane with the help of transport proteins.

Homeostasis

The maintenance of a constant internal state in a changing environment

Hypertonic

Solution that has a higher concentration of solutes outside the cell than inside the cell. When a cell is placed in a hypertonic solution, water will move out of the cell by osmosis to the area of higher solute concentration, causing the cell to shrink. 

Hypotonic

Solution in which the concentration of solutes is lower outside the cell than inside the cell. This causes water to move into the cell by osmosis, potentially causing the cell to swell and burst.

Isotonic

A solution that has the same concentration of solutes as another solution across a semipermeable membrane. When two solutions are isotonic, there is no net movement of water across the membrane, meaning the solutions are in equilibrium.

Mitosis

The process of cell division that results in the formation of two identical daughter cells.

Osmosis

The movement of water molecules across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.

Passive Transport

The movement of substances across a cell membrane without the use of energy.

Photosynthesis

The process by which green plants, algae, and some bacteria convert light energy into chemical energy.

Semipermeable Cell Membrane

An organelle which controls the movement of substances in and out of a cell, being semi permeable 

Concentration Gradient

amount of substance in a space (moves from high to low)

Equilibrium

state of being balanced, no changes are occuring

Solute

The substance that dissolves. example: sugar and koolaid powder

Solvent

The substance that does the dissolving. example: water

Solution

a solution is a type of mixture where one substance, the solute, dissolves evenly and completely into another substance, the solvent, example: finished koolaid drink

Meiosis

a type of cell division that reduces the number of chromosomes in a parent cell by half, producing four daughter cells called gametes