IB BIO TOPIC 2.2 : PROKARYOTIC & EUKARYOTIC CELLS Flashcards
What is the definition of a Prokaryotic cell ?
The prokaryotes are a group of organisms whose cells lack a membrane-bound nucleus.
What is the definition of a Eukaryotic cell ?
A eukaryote is an organism whose cells contain a nucleus and other structures enclosed within membranes.
What 5 functions does the cell wall have in a prokaryote ?
- ) It is always present
- ) It is composed of Peptidoglycan
- ) it provides physical protection
- ) It maintains cell shape
- ) prevents bursting in hypotonic environments
What are the 5 main functions of plasma membrane ?
- ) thin layer mainly composed of phospholipids pushed up against the inside of the cell wall.
- ) Provides selectively permeable barrier between homeostatically controlled interior and fluctuating exterior environments.
- ) Controls entry and exit of substances
- ) Can produce ATP by cell respiration
- Can also pump substances in and out by active transport
State the 4 main functions of the pili
- ) Protein filaments protruding from the cell wall.
- ) can be pulled in or push out by ratchet mechanism (laptop)
- ) used when bacteria stick together to form aggregations of cells
- ) Used when two cells are exchanging DNA during conjugation.
State the 4 main functions of the flagella
- ) structures protruding from cell wall with a corkscrew shape
- ) base is embedded in the cell wall.
- ) Using energy, they can be rotated to propel the cell from an area to another.
- ) Unlike eukaryotic flagella, they are solid and inflexible, working like a propeller.
State the 6 main functions of the cytoplasm
- Fluid filling the space inside the plasma membrane
- Water with many dissolved substances
- contains many enzymes
- contains ribosomes
- does NOT contain any membrane bound organelles
- carries out the chemical reactions of metabolism
State the 3 main functions of the ribosomes
- small granular structure (70S)
- smaller than eukaryotic ribosomes wich are 80S
- site for protein synthesis
State the 4 main functions of the nucleoid
- region of the cytoplasm containing the genetic material (1molecule of DNA)
- DNA is circular and naked (not associated with protein)
- Total amount of DNA is much smaller than in Eukaryotes
- the nucleoid is stained less densely than the rest of the cytoplasm because there are fewer ribosomes.
How do prokaryotic cells divide ?
By binary fission
Give 2 examples of prokaryotic cells
Bacteria for ex. E.Coli
Cyanobacteria for ex. Blue and Green Algae
State the 15 parts of a Eukaryotic cell
- Nucleus
- Microtubule
- Mitochondrion
- Rough endoplasmic reticulum (RER)
- Lysosome
- Microfilaments
- Vacuole
- Ribosomes
- Golgi complex
- Cell membrane
- Centrosomes
- Smooth endoplasmic reticulum (SER)
- Nucleolus
- Centriole
- Vesicle
What are the 2 main functions of free ribosomes ?
- Site for protein synthesis for use within the cytoplasm.
2. Ribosomes are constructed in the nuclear region called nucleolus.
State 3 main functions of Lysosomes
- spherical vesicles formed by Golgi apparatus
- Contain hydrolytic/ digestive enzymes
- Enzymes for breaking down ingested food, damaged organelles or entire cells.
State 5 main functions of Golgi apparatus
- consists of flattened membrane sacs called cisternae
- unlike ER, cisternae are curved shorter and lack ribosomes
- Proteins received from arriving vesicles are processed
- Carbohydrate added to proteins to form glycoproteins.
- Vesicles of glycoproteins exit Golgi for exocytosis or intracellular use.
