Biology: Cells and Eukaryotic Cells

Study Notes

Cells are the smallest unit of life that can replicate independently.
They are the basic building blocks of life, and all living organisms are made up of cells.

Both animal and plant cells are eukaryotic cells.
They have a cell membrane that controls what substances can pass in and out of the cell.
They have a nucleus that contains the genetic material (DNA) and controls the activities of the cell.
They are filled with a gel-like substance called cytoplasm, where chemical reactions take place.
They have mitochondria that provide energy for the cell through aerobic respiration.
They have ribosomes that are the site of protein synthesis.

Plant cells have a rigid cell wall around the entire cell, made up of cellulose.
The cell wall provides support and structure to the cell.
They have a permanent vacuole, a large sac that contains cell sap (a mixture of sugars, salts, and water).
They have chloroplasts, where photosynthesis occurs, and contain chlorophyll, which absorbs light energy.

Bacterial cells are prokaryotic cells and consist of a single cell (unicellular).
They have a cell membrane, a cell wall, ribosomes, and cytoplasm.
They do not have mitochondria or chloroplasts.
They do not have a nucleus; instead, they have a single circular strand of DNA (circular chromosome or nucleoid) that contains all the genes needed for survival and reproduction.
Some bacteria have additional small rings of DNA called plasmids, which carry extra genes like antibiotic resistance.
Some bacteria have flagella, thread-like structures that allow them to move around.

Rigid cell wall provides support and structure to the cell.
Cell wall is made up of cellulose.
Permanent vacuole is a large sac that contains cell sap (a mixture of sugars, salts, and water).
Chloroplasts are where photosynthesis occurs and contain chlorophyll, which absorbs light energy.

Bacterial cells are single-celled (unicellular).
Cell membrane, cell wall, ribosomes, and cytoplasm are present.
Mitochondria and chloroplasts are absent.
A single circular strand of DNA (circular chromosome or nucleoid) contains all genes needed for survival and reproduction.
Plasmids are small rings of DNA that carry extra genes like antibiotic resistance.
Some bacteria have flagella, thread-like structures that allow them to move around.

Rigid cell wall provides support and structure to the cell.
Cell wall is made up of cellulose.
Permanent vacuole is a large sac that contains cell sap (a mixture of sugars, salts, and water).
Chloroplasts are where photosynthesis occurs and contain chlorophyll, which absorbs light energy.

Bacterial cells are single-celled (unicellular).
Cell membrane, cell wall, ribosomes, and cytoplasm are present.
Mitochondria and chloroplasts are absent.
A single circular strand of DNA (circular chromosome or nucleoid) contains all genes needed for survival and reproduction.
Plasmids are small rings of DNA that carry extra genes like antibiotic resistance.
Some bacteria have flagella, thread-like structures that allow them to move around.