Cell Biology: Eukaryotes, Prokaryotes, and Cell Structures

Practice vocabulary flashcards defining key cell biology terms, organelles, and distinguishing features of animal, plant, and bacterial cells.

Cells

The basic building blocks of life, defined as the smallest unit of life that can replicate independently.

Multicellular

Organisms containing loads of cells, such as animals and plants, where cell division functions primarily for growth or replacing dead cells.

Subcellular structures

The different parts that make up a cell, also referred to as organelles.

Cell membrane

The structure surrounding a cell that controls which substances can pass in and out of the cell.

Nucleus

The structure containing the genetic material or DNA of the cell that effectively controls the activities of the cell.

Cytoplasm

A gel-like substance resembling jelly where subcellular structures sit and where chemical reactions take place.

Mitochondria

Organelles whose job is to provide cells with the energy they need to function by breaking down sugars like glucose.

Aerobic respiration

The process in mitochondria that breaks down sugars such as glucose to release energy the cell can use.

Ribosomes

Subcellular structures common to both animal and plant cells that serve as the site of protein synthesis.

Cellulose

A really strong material that makes up the rigid cell wall in plant cells.

Cell wall

A rigid outer layer in plant cells made of cellulose that provides support and structure to prevent the cell from bursting if too much water enters.

Permanent vacuole

A large sac in plant cells that takes up much of the cell space and stores cell sap.

Cell sap

A mixture of sugars, salts, and water stored in the permanent vacuole that the cell can use when needed.

Chloroplasts

Subcellular structures found in plant cells where photosynthesis takes place.

Photosynthesis

The process by which plants use energy from the sun to make sugars such as glucose.

Chlorophyll

A green substance inside chloroplasts that absorbs the light energy required for photosynthesis and gives plant leaves their green color.

Unicellular

A one-cell organism, such as a bacterium, where each individual cell constitutes an entire organism.

Circular chromosome (nucleoid)

A single circular loop or strand of DNA in bacteria that floats freely in the cytoplasm and carries all the genes required to survive and reproduce.

Plasmids

Additional small rings of DNA present in some bacteria that carry extra genes, such as antibiotic resistance.

Legella

Thread-like structures protruding from some bacteria that rotate to propel the organism along, allowing it to move around.