Grade 8 Cell Biology: Organelles, Living Things, and Transport

Comprehensive vocabulary flashcards reviewing Grade 8 cell organelles, characteristics of living things, cell theory, and diffusion/osmosis concepts.

Nucleus

The organelle described as the "control center" of the cell that controls cell activities and contains DNA.

Cell membrane

A selectively permeable boundary that controls what enters and leaves the cell, allowing small molecules to pass while blocking others.

Cell wall

A supportive layer located outside the cell membrane that provides structure and support in plant cells that animal cells lack.

Mitochondria

Organelles surrounded by $2$ layers of membrane that release energy from food and convert it into usable energy (ATP) through cellular respiration.

Cytoplasm

The fluid portion of the cell that holds organelles in place and allows materials to move around.

Chloroplast

An organelle found in plant cells (but not in animal cells) that captures sunlight to make food through photosynthesis.

Granum

Pancake-like stacks found inside chloroplasts where photosynthesis actually takes place.

Ribosomes

Organelles responsible for producing proteins; they are found floating in the cytoplasm and attached to the rough ER.

Endoplasmic Reticulum (ER)

An organelle that works together with ribosomes to help make proteins and produce other materials needed by the cell.

Rough ER

The region of the endoplasmic reticulum that is studded with ribosomes and aids in making proteins.

Smooth ER

The region of the endoplasmic reticulum that lacks ribosomes and has the main job of producing non-proteins needed by the cell.

Golgi apparatus

An organelle compared to an Amazon warehouse because it packages and ships proteins around the cell or out of the cell.

Lysosome

An organelle containing enzymes that break down biomolecules, cellular waste, and old cell parts.

Central vacuole

A large organelle in plant cells that mainly stores water and helps maintain cell shape; animal cells tend to have much smaller vacuoles.

Cellular respiration

The metabolic process carried out by mitochondria that converts food energy into usable energy (ATP) for the cell.

Photosynthesis

The process occurring in chloroplasts that uses sunlight to provide food for plant cells.

Characteristics of living things

The $8$ essential traits an organism must display to be considered alive, including reproducing, requiring energy, producing wastes, and having a lifespan.

Unicellular organism

An organism consisting of only one single cell, such as a bacterium.

Sexual reproduction

A form of reproduction that requires two sex cells to produce offspring.

Asexual reproduction

A form of reproduction that requires only one parent cell.

Autotroph

An organism that gets its energy from the sun through the process of photosynthesis.

Heterotroph

An organism that gets its energy by consuming nutrients from its environment.

Cell Theory

A foundational biological principle stating that all cells come from pre-existing cells.

Theodore Schwann

The scientist credited with proposing that animals are entirely made of cells.

Diffusion

The automatic movement of matter from an area of high concentration to an area of low concentration (such as perfume spreading in a room or oxygen entering cells from blood).

Osmosis

The diffusion of water across a selectively permeable membrane from an area of high water potential to low water potential.

Water potential

A property describing the concentration of water in a solution; high in solutions with lots of water compared to solid material, and low when there is very little water.