Cells Flashcards
What is a cell?
A cell is the basic building block of all living things. The human body is composed of trilions of cells, which provides structure for the body, takes in nutrients from food, convert those nutrients into energy and carry out specialized functions. These cells have different shapes and sizes.
Which categories of cells exist?
Cells can be separated into two broad categories:
- Eukaryotic cells (for example the protozoan)
- Prokaryotic cells (for example the bacterium)
How do eukaryotic and prokaryotic cells differ?
- Eukaryotic cells have a nucleus and other membrane-bound organelles. The nucleus, the largest organelle, encloses the genetic information (DNA). Eukaryotes may be multicellular or single-celled organisms.
- Prokaryotic cells do not have a nucleus or other membrane-bound organelles. Instead, the cell’s DNA is suspended in the cytoplasm. Most prokaryotes are microscopic single-celled organisms.
What is special about cells?
In general, cells trend to be microscopic in size and have similar building blocks. The are also enclosed by a cell membrane that controls the movement of materials into and out of the cell.
How does the cell structure of animal and plant cells differ?
Animal cells do not have:
- Chloroplasts
- Central vacuole
- Cell wall
Plant cells do not have:
- Centrioles
- Lysosomes
REMEMBER!
- Cells have an internal structure!
- Several organelles are involved in making and processing proteins!
- Other organelles have various functions!
- Plant cells have cell walls and chloroplasts!
- Prokaryotic cells lack a nucleus and most internal structures of eukaryotic cells!