Characteristics of All Cells Flashcards
+ différences between viruses and cells, prokaryotic cells and eukaryotic cells . (15 cards)
What ia a cell? And what are the 4 principles of modern cell theory?
A cell is the simples organization that can still be considered “alive”
1. Every living organism is composed of one or more cell
2. The smallest living organisms are single cells, and cells are the functional units of multicellular organisms
3. All cells come from pre-existing cells
4. Cells contain hereditary material, which they pass to their offspring when they reproduce
What does all the cells have in common?
They share a common evolutionnary ancestor
What is an organelle?
A complex assemble of molecules forming a structure that performs a specialized function for the cell
organs of the cell
Basic characteristic of all cells
What are the characteristics of the plasma membrane (cellular membrane)? (5)
- Selectively isolates the cell’s internal contents from the external environment
- Regulates the flow of materials into and out of the cell
- Allows for interactionwith other cells and the extracellular environment
- Regulates some biochemical reactions
- Helps attach cells together
Basic characteristic of all cells
What is the cytoplasm composed of ? (2)
- A fluid-like medium containing the organelles, between the plasma membrane and the region holding the DNA
- Cytosol = only the fluid part
Basic characteristic of all cells
How does the cell uses DNA as the molecule of heredity?
It uses DNA as “molecular blueprint”, which holds instructions on how to build and operate parts of the cell or build another cell
Basic characteristic of all cells
Why are cell microscopic in size?
- Their ability to obtain nutrients depends on surface area (+ SA = ++ Volume)
- If the cell is too big, it can’t provide itself with anout nutrients
What are the differences between prokaryotic cells and eukaryotic cells?
Size
Pro: small
Eu: large
Organelles found on the surface of the cell
Pro: pili, capsule (unique to pro.)
Eu: cilia, pseudopods (unique to eu.)
Organelles found in the citoplasm
Pro: few
Eu: many different
Pro rhymes with NO!, Eu rhymes with DO!
What are the characteristics of viruses that makes them not to be considered as cells?
4
- Not alive but acts as if it was
- Can’t reproduce on their own (must hijack the DNA replication machinery found in the host cell in order to reproduce)
- Don’t have a plasma membrane or cytoplasm
- Smaller than the smallest cell
What is the cytoskeloton made of? What is its functions (4)? And which type of cell has it?
Its a network of protein filaments that run throughout the cell
Functions:
1. Transport of substances in the cell
2. Movement of the cell
3. Shape of the cell
4. Cell division
Found in all cell types
What is the nucleus? What does it contains? What are the roles of each of these elements? And which type of cell have one?
It’s an organelle that holds the cell’s DNA
It consists of:
1. A nuclear envelope
- Selectively isolates the contents of the nucleus from the rest of the cytoplasm.
2. Nucleolus
- Location where the ribosomes are built.
3. Chromatin
- Storage form of DNA, contains the information required to operate the cell.
Found only in Eukaryotic cells
Ribosomes produces proteins in the cell
The Rough Endoplasmic Recticulum is called The Rough ER
What is the Rough ER made of? What is its functions? And in which cell type is this found?
It is made of a long series of winding, flattened, membranous sacs covered with ribosomes
It is the location where proteins destines for the plasma membrane take on their final folded shape
It repairs proteins that don’t get folded correctly
In other words: It takes the proteins to make sure they have the right structure
Found only in Eukaryotic cells
What are vesicles (structure)? Their function? And in which cell type are they found?
Structure: Small, hollow organelles that are surrounded by a membrane.
Function: Transport and store substances inside the cell. Difference between cell types: only found in eukaryotic cells BUT NOT IN PROTISTS CELLS)
What is a mitochondria?
Structure: Small, double-membraned organelles.
Function: Use oxygen to produce the majority of the cell’s energy (aerobic cellular respiration). Difference between cell types: only found in eukaryotic cells.
What are chloroplasts?
Structure: Small, double-membraned organelles.
Function: Use light, H2O, and CO2 to form their food in the form of simple sugars (photosynthesis). Difference between cell types: only found in plant and some protist cells.
