Cells Flashcards
What is the function of the nucleus?
- Stores DNA as chromatin
- Coordinates cell’s activities, such as growth, protein synthesis and reproduction.
What is the function of the plasma membrane?
- Surrounds cell to provide a physical barrier to control exit and entry of substances
- Allows communication between cells
- Detects and responds to environmental changes
What is the function of the nucleolus?
- Produces rRNA and combines it with other proteins
- Releases them through nucleur envelope
What is the function of the Rough Endoplasmic Reticulum?
Ribosomes on the RER synthesis and package proteins into vesicles
What is the function of the Golgi apparatus?
Modifies proteins then repackages them into vesicles.
What is the function of lysosomes?
Break down cellular waste, such as dead/damaged organelles and pathogens.
What is the function of the Smooth Endoplasmic Reticulum?
- Contains enzymes which helps with the creation of important lipids
- Stores ions and helps cells detox
What is the function of ribosomes?
Site for protein synthesis to occur
What is the function of mitochondria?
Carries out aerobic respiration
What is the function of the chloroplast?
Carry out photosynthesis
What is the function of the permanent vacuole
Stores cell sap, which helps keep the cell turgid.
What is the function of centrioles?
Produces cillia during interphase
Produces aster and spindle during cell division
What is the function of the vacuole (many)
Play an important role in endocytosis and exocytosis is by storing waste material
Can destroy bacteria when the bacterium is engulfed
What is the function of the cell wall?
Provides cell with both structural support and protection
Acts as a filtering mechanism
What are the key differences between prokaryotic cells and eukaryotic cells
- Eukaryotes have a nucleus, pro don’t
- Eukaryotes have membrane-bound organelles, pro don’t
- Eukaryotes are typically bigger than pro
What is the prokaryote cell ultrastructure?
- Outer membrane
- inner membrane
- DNA
- ribosomes
- flagellum (some)
- cytoplasm
- cell wall
- bacterial chromosome
- pilli
Organelles involved in protein production.
Rough Endoplasmic Reticulum Ribosomes (on RER) Vesicles Golgi apparatus Cytoskeleton Cell surface membrane
Process of protein production and synthesis.
1) RNA produced by nucleus
2) Ribosomes attached to rough Endoplasmic reticulum carry out protein synthesis and package proteins into vesicles
3) Vesicles travel to Golgi apparatus via cytoskeleton
4) Vesicles fuse with cis. face of Golgi apparatus and proteins enter
5) In Golgi Apparatus, proteins are structurally modified and repackaged into vesicles
6) Vesicles travel via cytoskeleton and fuse with the cell surface membrane and proteins exit via exocytosis.
What is the ultrastructure of plants?
80s free ribosome Chloroplasts Tonoplast Golgi apparatus Nucleus Nucleuolus RER SER mitochondria Plasma membrane Cell wall
What is the difference in DNA in pro and eukaryotic cells?
Prokaryotes have
- Naked DNA
- Circular DNA
- No introns (usually)
Eukaryotes have
-DNA bound to protein
-Linear DNA
Has introns (usually)
What is the difference in reproduction between pro and eukaryotic cells?
Prokaryotic cells:
- Binary fission
- Single chromosome
Eukaryotic cells:
- Mitosis and meiosis
- Chromosomes paired
What is the difference in average size between pro and eukaryotic cells?
Prokaryotic cells:
- Smaller
- 1 to 5 micrometers
Eukaryotic cells:
- Larger
- 10 to 100 micrometers
What is the cytoskeleton composed of?
- Microfilaments
- Microtubules
- Intermediate fibres
What are microfilaments?
- Solid and smaller than microtubules
- Composed of actin
- Provide contractile motion
- Involved in cytokinesis
- Act as a skeleton to support the cell
- Responsible for cell movement
What are microtubules?
- Composed of globular tubular proteins
- Polymerise to form hollow tube that act as a scaffold
- This scaffold determines cell shape
- Acts as roads for vesicles and organelles
- Self assemble from hollow tube units to form cilia and flagella
- Forms spindle fibres that separate chromosomes during cell division.
What are intermediate filaments?
- Intermediate diameter between microtubules and microfilaments
- Entwined dimers of various proteins
- Add mechanical strength and help maintain integrity of the cytoskeleton.
