Chapter 1 Flashcards
What are the three parts of the cell theory? What does the modern cell theory ask?
- All living things are composed of cells.
- Cells are the basic unit of life.
- All cells come from pre-existing cells.
Modern cell theory: Cells contain genetic material in the form of DNA that will be passed on from parent to daughter cell.
How does a prokaryote differ from an eukaryote?
A prokaryote is unicellular and does not contain a membrane-bound nucleus or other organelles. A eukaryote can be multicellular or unicellular, has a membrane-bound nucleus, and has major organelles.
Describe the structure of a nuclear membrane.
The nuclear membrane is a double-membrane that maintains a nuclear environment separate and distinct from the cytoplasm. Nuclear pores in the nuclear membrane allow selective exchange of material between the cytoplasm and nucleus.
Where is rRNA synthesized?
rRNA is synthesized in the nucleolus.
Describe the membrane structure and function of the mitochondria.
The outer membrane serves as a barrier between the cytosol and the inner environment of the mitochondrion. The inner membrane, arranged in multiple folds (cristae), contain the molecules and enzymes of the electron transport chain.
Which organelle is semi-autonomous? What does that mean?
The mitochondrion is semi-autonomous. They contain some of their own genes and replicate independently via binary fission.
What are lysosomes?
Lysosomes are membrane-bound structures containing hydrolytic enzymes that are capable of breaking down substrates via lytic enzymes.
What is the endoplasmic reticulum? What are the two subtypes and what are their functions?
The ER is a series of interconnected membranes that are contiguous with the nuclear envelope.
The RER is studded with ribosomes where translation happens.
The SER is primarily used for lipid synthesis and detoxification of certain drugs. It also transports proteins from the RER to the Golgi.
What is the Golgi apparatus and what is its function?
The Golgi apparatus consists of stacked membrane-bound sacs. The Golgi modifies proteins by addition of functional groups and allows targeting of a product to a specific cellular location.
What are peroxisomes?
Peroxisomes contain hydrogen peroxide and is responsible for the breakdown of very long chains of fatty acids via beta-oxidation.
The three components of the cytoskeleton are…
Microfilaments, microtubules, and intermediate filaments.
Describe the structure and function of microfilaments.
Microfilaments are made up of actin polymers which provides protection for the cell. They also play a role in cytokinesis.
Describe the structure and function of microtubules.
Microtubules are made up of tubulin proteins and provide pathways along which motor proteins (i.e. Kinesin/Dynein) transport vesicles.
What are cilia and flagella?
Cilia and flagella are motile structures composed of microtubules. Cilia are projections from a cell that are primarily involved in the movement of materials along the surface of the cell (i.e. Mucous). Flagella are structures involved in the movement of the cell itself.
What is the 9+2 structure?
The 9+2 structure describes the structure of cilia and flagella - 9 pairs of microtubules forming an outer ring with two microtubules in the centre.
