Chapter 1: The Cell Flashcards
(32 cards)
What is are 4 basic tenets of cell theory?
- All living things are composed of cells.
- The cell is the basic functional unit of life.
- Cells arise only from preexisting cells.
- Cells carry genetic information in the form of deoxyribonucleic acid (DNA). This genetic material is passed on from parent to daughter cell.
Name differences between a prokaryotic and eukaryotic cell.
- prokaryotic organisms are always single-celled
- eukaryotic organisms can be unicellular or multicellular
- eukaryotic cells contain a true nucleus enclosed in a membrane
- prokaryotic cells do not contain a nucleus
Why the nuclear envelope important?
Because it creates two distinct environments within the cell (separates the nucleus from the cytoplasm). This allows for the compartmentalization of transcription.
Discuss the outer and inner membranes of the mitochondria.
outer membrane - serves as a barrier between the cytosol and the inner environment of the mitochondrion.
inner membrane - is arranged into numerous inholdings called cristae and it contains molecules and enzymes of the ETC.
Define cristae
the inner membrane of the mitochondria which is arranged into numerous inholdings is called the cristae, and contains molecules and enzymes of the electron transport chain.
What is the space between the inner and outer membrane called in the mitochondria?
the space between the inner and outer membrane is called the intermembrane space.
What is the space inside the inner membrane called? (mitochondria)
the space inside the inner membrane is called the mitochondrial matrix.
How is the mitochondria semi-autonomous? What is this an example of?
Mitochondria are semi-autonomous in that they contain some of their own genes and replicate independently of the nucleus VIA binary fission.
This is an example of cytoplasmic or extranuclear inheritance - the transmission of genetic material independent of the nucleus.
What is the thought of how mitochondria originated?
mitochondria are thought to have originated when the engulfing of an aerobic prokaryote by an anaerobic prokaryotic resulted in a symbiotic relationship.
What are lysosomes?
lysosomes are membrane-bound structures containing hydrolytic enzymes that are capable of breaking down many different substrates.
What are endosomes?
endoscopes transport, package, and sort cell material travelling to and from the membrane.
What is the endoplasmic reticulum?
the ER is a series of interconnected membranes that are actually contiguous with the nuclear envelope.
Describe the structure of the ER.
the double membrane of the ER is folded into numerous invaginations, creating complex structures with a central lumen.
What is the difference between the rough ER (RER) and the smooth ER (SER)?
- the RER is studded with ribosomes, which permit the translation of proteins destined for section directly into its lumen.
- the SER lacks ribosomes and is utilized primarily for lipid synthesis (such as phospholipids in the cell membrane) and the detoxification of certain drugs and poisons. also transports proteins from the RER to the Golgi apparatus.
What is the function of the Golgi apparatus?
- cellular products may be modified by the addition of groups like carbohydrates, phosphates, and sulphates.
- Golgi apparatus may also modify cellular products through the introduction of signal sequences which direct the delivery of the product to a specific cellular location.
What is peroxisomes and what is it’s function?
Peroxisomes contain hydrogen peroxide.
One of the primary functions of peroxisomes is the breakdown of very long chain fatty acids VIA β-oxidation.
What is the cytoskeleton?
the cytoskeleton provides structure to the cell and helps it to maintain its shape and provides a conduit for the transport of materials around the cell.
What are microfilaments composed of and what is its function?
microfilaments are made up of solid polymerized rods of actin.
microfilament are resistant to both compression and fracture, providing protecting for the cell.
What is the role of microfilaments in cytokinesis?
during mitosis, the cleavage furrow is formed from microfilaments, which organize as a ring at the site of division between the two new daughter cells. as the actin filaments within this ring contract, the ring becomes smaller, eventually pinching off the connection between the two daughter cells.
What are microtubules composed of and what is its function?
microtubules are hollow polymers of tubular proteins.
microtubules radiate through the cell providing the primary pathways along which motor pathways like kinesin and dynein carry vesicles.
What is 9+2 structure? Where is it found? What are some examples of a 9+2 structure?
a 9+2 structure is composed of nine pairs of microtubules forming an outer ring, with two microtubules in the centre.
a 9+2 structure is seen only in eukaryotic organelles of MOTILITY.
cilia and flagella are motile structures composed of microtubules in the 9+2 structure.
What are centrioles and what is its function?
centrioles are found in region of the cell called the centrosomes. they are the organizing centres for microtubules.
What is kinetochores and what is its function?
the microtubules emanating from the centrioles attach to the chromes VIA complexes called kinetochores and exert force on the sister chromatid, pulling them apart.
What are intermediate filaments, and what is their function?
intermediate filaments are a diverse group of filamentous proteins, which includes keratin, design, vimentin and laming.
many intermediate filaments are involved in cell-cell adhesion or maintenance of the overall integrity of the cytoskeleton.
