Cell Biology Flashcards
Define and describe ‘cytosol’.
A concentrated aqueous gel of large and small molecules.
- Also referred to as the intracellular fluid.
- Has a high water content.
- Site of many chemical reactions.
Define and describe ‘cytoplasm’.
A jelly-like substance of the cell, including all contents of a cell except for the nucleus in eukaryotic cells.
- Water based
- Contains organelles
- Components: filaments + fibers, fluids, storage.
Define and describe ‘mitochondria’.
A membrane bound organelle present in almost all eukaryotic cells, their primary function is to generate energy in the form of ATP.
- Has its own DNA.
- Bound by a double membrane.
- Breaks down fuel molecules.
Define and describe ‘nucleus’.
A membrane bound organelle that contains genetic material of eukaryotic organisms.
- Control centre
- Dounble membrane (nuclear envelope)
- Contains chromosomes
Define and describe ‘chloroplasts’.
Large, green organelles present in plants and green algae.
- Carries out photosynthesis.
- Double membrane
- Has its own DNA.
What is the endosymbiotic theory?
- Infolding in PM of ancestra prokaryotes gave rise to endomembrane compartments, including a nucleus and ER.
- Ancestral eukaryote ingested aerobic bacteria, which envolved into the mitochondria.
- Ancestral eukaryote ingested photosynthetic bacteria, which envolved into the chloroplasts.
- Both developed a symbiotic relationship with their respective eukaryotic cells.
Define and describe ‘lysosomes’.
Small organelles in which intracellular digestion occurs.
- Contains digestive enzymes.
- Aids in cell renewal.
- More common in plants.
- Contents: water, food, waste.
Define and describe ‘chromosomes’.
The thread-like structure that the DNA molecules are packaged into.
Define and describe ‘golgi apparatus’.
A membrane bound organelle in eukaryotic cells made up of a series of flattened, stacked pouches called cisternae.
- Synthesis of plant wall.
- Modifying and packaging molecules.
Define and describe ‘peroxisomes’.
Small, membrane bound organelles in the cytoplasm of eukaryotic cells.
- Provides a safe environment for a variety of reactions to take place.
- Including: hydrogen peroxide being used to inactivate toxic materials.
Define and describe ‘plasma membrane’.
A network of lipids and proteins that form the boundary between cell’s contents and the outside of a cell.
- Made up of phospholipids arranged in double layer.
- Also contains proteins and carbohydates (fluid mosaic model).
Define and describe ‘endoplasmic reticulum’.
A continious network of interconnected membranes forming flattened sacs within the cytoplasm.
- Helps with synthesis, folding, modification and transport of proteins.
- Rough ER and Smooth ER.
Define and describe ‘cytoskeleton.
A network of filaments and tubules that extends throughout a cell.
- Helps in molecule transport, cell division and cell signalling.
- 3 major filaments: actin filaments, microtubules and intermediate filaments.
Describe the characteristics of Rough ER.
- Contains many ribosomes (not all are attached).
- Tight proximity to the nucleus.
- Protein synthesis
- Can modify proteins from ribosomes.
Describe the characteristics of Smooth ER.
- Has enzymes to help build lipids and carbohydrates.
- No ribosomes
