Chapter 5 - Cellular Biology Flashcards
What is the fundamental unit of all living things?
TheDCell.
Describe the 5 aspects of The Cell Theory:
1) All living things are composed of cells.
2) The cell is the basic functional unit of life.
3) The chemical reactions of life take place inside the cell.
4) Cells arise only from pre-existing cells.
5) Cells carry genetic info in the form of DNA - This genetic material is passed from parents cell to daughter cell.
What organelles can be located within cells?
Nucleus, ribosomes, endoplasmic reticulum, Golgi apparatus, vesicles, vacuoles, lysosomes, mitochondria, chloroplasts, and centrioles.
What are the 6 Kingdoms?
1) Bacteria
2) Archaea
3) Protista
4) Fungi
5) Plantae
6) Animalia
Describe prokaryotes vs. eukaryotes:
1) Prokaryotes
- “Before nucleus”
- Lack membrane-bound nuclei and organelles
- Consist mostly of ribosomes and genetic material
Describe the cell membrane in relation to its permeability, the fluid mosaic model, and carrier proteins:
The cell membrane encloses the cell and exhibits selective permeability which regulates passage of materials into and out of the cell.
The fluid mosaic model describes the cell membrane having a phospholipid membrane bilayer that has proteins embedded throughout.
- The phospholipid bilayer is arranged such that long, non-polar, hydrophobic fatty chains of carbon and hydrogen face each other (water-free region), with the phosphorous-containing, polar, hydrophilic heads facing outward (water region).
- This results in permeability to small, non-polar, hydrophobic molecules while larger and polar molecules cross the membrane via carrier proteins.
Describe the nucleus in regard to histones, chromosomes, nucleolus, and ribosomal RNA:
The nucleus controls all activities of the cell and is surrounded by a nuclear membrane - it contains the DNA which is complexed with structural proteins called histones that form chromosomes.
- DNA winds around histones to be compact, and the histones are involved with regulation of gene transcription.
The nucleolus is a dense structure in the nucleus where ribosomal RNA synthesis occurs.
Describe the ribosome in relation to production, synthesized, and free vs. bound ribosomes:
Ribosomes are the sites of protein production and synthesized by the nucleolus.
- Free ribosomes are found in the cytoplasm
- Bound ribosomes are found in he outer membrane of the endoplasmic reticulum
Describe the endoplasmic reticulum in relation to smooth vs. rough ER:
The ER is a network of membrane-enclosed spaces involved in transport of materials throughout the cells, mostly destined to be secreted.
- Smooth ER does not contain ribosomes and is involved with metabolism and production of lipids
- Rough ER contains ribosomes and is involved with protein production
Describe the Golgi apparatus:
The Golgi apparatus receives vesicles and their contents from smooth ER and packages them into vesicles to be distributed to the cell surface for exocytosis.
Describe the mitochondria:
The mitochondria is the site of aerobic respiration within the cell and supplies energy in the form of ATP
- They have an outer and inner phospholipid bilayer
Describe the cytoplasm:
Most of the cell’s metabolic activity occurs in the cytoplasm, which includes the cytosol and cellular organelles.
- Transport within the cytoplasm occurs via cyclosis
Describe the vacuoles/vesicles:
They are membrane bound sacs involved in transport and storage of materials ingested, secreted, processed, or digested by the cell
- Vacuoles are larger than vesicles and are more likely to be found in plant rather than animal cells
Describe centrioles:
Centrioles are composed of microtubules and are involved in spindle organization during cell division
- Not bound by a membrane
- Animals cells have a pair of centrioles organized at right angles to one another in a region called the centrosome
- Regulate progression of cell cycle
- Plant cells do not contain centrioles
Describe lysosomes:
Lysosomes are membrane-bound vesicles that contain hydrolytic enzymes involved in intracellular digestion
- Break down ingested material
- Injured/dying cells will self-destruct by rupturing the lysosome membrane and releasing the hydrolytic enzymes (autolysis)
Describe the cytoskeleton in relation tubulin, cilia, flagella, and actin:
The cytoskeleton supports the cell, maintains shape, and aids in motility - it is composed of microtubules, microfilaments, and intermediate filaments.
- Microtubules are hollow rods made up of polymerized tubulin that radiate throughout cell and provide support and organelle movement (ex. controls, cilia, flagella)
- Microfilaments are solid rods of actin which are important for cell movement and support, and move materials across the plasma membrane (ex. muscle contraction)
What types of cellular transport is there?
1) Active
2) Passive
What is simple diffusion? Energy required?
Net movement of dissolved particle down their concentration gradients from a region of higher concentration to a region of lower concentration.
- Passive process = requires no energy
Describe osmosis in relation to hypertonic vs. hypotonic vs. isotonic:
Simple diffusion of water from region of lower solute concentration to region of higher solute concentration
- Hypertonic: Cytoplasm of cell has lower solute concentration than ECM (cell shrivels)
- Hypotonic: ECM is less concentrated than cytoplasm of the cell (lyse/swell)
- Isotonic: ECM has same concentration as cytoplasmic of cell
What is facilitated diffusion?
The net movement of dissolved particles down their concentration gradient through special channels or carrier proteins in the cell membrane
- Does not require energy
What is active transport? Symporters vs. antiporters vs. pumps?
The net movement of dissolved particles against their concentration gradients with the help of transport proteins
- Requires energy
- Carrier molecules aid in regulation of cell’s internal content of ions and large molecules
- Symporters: Move two or more ions or molecules in the same direction across membrane
- Antiporters: Exchange one or more ions for another ion or molecule across the membrane
- Pumps: Energy dependent carriers (ATP) - Ex. NA/K Pumps
What is endocytosis? Pinocytosis vs phagocytosis?
It is a process in which the cell membrane invaginate, forming a vesicle that contains the ECM that allows the cell to bring in large volumes of ECM inside the cell
- Particles may first bind to receptors on the cell membrane before being engulfed
- Pinocytosis: Ingestion of fluids or small particles
- Phagocytosis: Engulfing of large particles
What is exocytosis?
A vesicle within the cell fuses with the cell membrane and released a large volume of contents to the outside
- Fusion of the vesicle within the cell membrane can play an important role in cell growth and intercellular signalling
Describe intracellular circulation in relation to Brownian vs. Cyclosis vs. Endoplasmic Reticulum:
Materials that move about within a cell in a number of ways:
- Brownian Movement: Kinestic energy spreads small suspended particles throughout the cytoplasm
- Cyclosis or Streaming: The circular motion of cytoplasm around the cell transports molecules
- Endoplasmic Reticulum: The ER forms a network of channels throughout the cytoplasm and provides a direct continuous passageway from the plasma membrane to the nuclear membrane
