Bio Final

• Ribosomes in both bacteria and archaea are similar in size and function, but their primary structure of RNA and protein components differ slightly.
• Prokaryotic cells have distinctive structures and functions, contain at least one chromosome, ribosomes, and phospholipid structures differ between bacteria and archaea.
• Ribosomes are macromolecular machines built of large and small subunit, composed of RNA molecules and proteins, and are essential for protein synthesis (translation).
• Prokaryotic cells may also contain circular, supercoiled DNA molecules called plasmids, which code for additional life support services such as antibiotic resistance.
• All cells contain proteins that perform most of the cell’s functions, nucleic acids that store, transmit, and process information, and carbohydrates that provide chemical energy, carbon, support, and identity.
• The chromosome is the most prominent structure inside a prokaryotic cell, consisting of a large DNA molecule which contains instructions for essential proteins.
• The cell membrane serves as a selectively permeable membrane barrier and is composed of phospholipids (and other various molecules).
• Cells are divided into two fundamental types based on physical traits: Eukaryotes contain a membrane-bound nucleus, while Prokaryotes do not contain a membrane-bound nucleus.
• Each of these cells contain additional specialized structures called organelles, whose structures are specific to their functionality.
• The primary structural component of the cell wall of prokaryotes is polysaccharide (carbohydrate).
• Most eukaryotes have a cell wall composed of a tough, fibrous layer surrounding the plasma membrane.
• internal photosynthetic membranes convert energy in sunlight to chemical energy.
• Prokaryotes contain enzymes and pigment molecules required for reactions to occur.
• Nuclear proteins contain a 17-amino-acid-long nuclear localization signal (NLS) that marks proteins for transport through nuclear pore complex and allows them to enter the nucleus.
• Prokaryotes maintain cell shape.
• The nucleus is perforated with pore-like openings called nuclear pore complexes that allow things to enter/leave the nucleus.
• Eukaryotes may be unicellular or multicellular and belong to the Domain: Eukarya, Kingdoms: Fungi, Plantae, Protista, and Animalia.
• The nucleolus connects the inside of the nucleus with cytosol of the cell.
• The nucleus contains a distinctive region known as the nucleolus, where ribosomal RNA (rRNA) is synthesized and ribosome subunits assembled, but these processes do not occur here.
• Many prokaryotes interact with the environment through specialized structures that extend from their plasma membrane, the two most prominent being flagella and fimbriae.
• The import of large molecules into the nucleus is very selective and serves as a gate to control passage.
• Eukaryotes contain internal organelles, while prokaryotes do not.
• The Nuclear envelope separates the nucleus from the rest of the cell and consists of ~30 different proteins.
• The nucleus is a large, highly organized membrane-bound compartment surrounded by a double-membrane nuclear envelope and contains the genetic material (DNA) of the cell.
• Prokaryotes do not contain membrane bound organelles.
• Transport vesicles leaving the Golgi apparatus that are destined to leave the cell exit via exocytosis.
• Proteins enter Golgi apparatus at cis face, are modified as they move within compartments at different stages of maturation, and leave Golgi apparatus with molecular tag and placed inside transport vesicles.
• Smooth endoplasmic reticulum does not have ribosomes, contains enzymes that catalyze reactions involving synthesis or breakdown of lipids, serves as a reservoir for Ca 2+ ions, and is involved in cell signaling.
• Rough endoplasmic reticulum is studded with ribosomes, is dark, knobby looking, and is the site of translation.
• Golgi apparatus is constantly changing, new cisternae form at cis face, old cisternae break off from trans face and are replaced by cisternae behind them, and different cisternae contain different proteins.
• Most proteins leaving RER must pass through Golgi apparatus, arrive in vesicles, and the Golgi apparatus processes, sorts, and ships proteins synthesized in RER.
• Some ribosomes are free in the cytosol and manufacture proteins that are in cytosol or are imported to other organelles.
• Ribosomes are complex molecular machines that manufacture proteins and are membrane-bound organelles.
• Endoplasmic reticulum is an extensive membrane-enclosed factory with a nuclear envelope and two regions with distinct structure and function: Rough endoplasmic reticulum (rough ER or RER) and Smooth endoplasmic reticulum (smooth ER or SER).
• Rough endoplasmic reticulum manufactured proteins move to RER (i.e., opening) and inside the RER lumen, proteins are folded and processed (post-translational modification).
• Proteins made on RER may carry to other cells, act as membrane transporters or pumps by inserting into plasma membrane, or catalyze reactions.
• Golgi apparatus is a membranous network of stacked, flat, membranous sacs called cisternae, has two distinct sidedness or polarity, and functions by processing, sorting, and shipping proteins synthesized in RER.
• Some ribosomes are attached to endoplasmic reticulum and manufacture proteins with other fates, such as the cell.
• The Second Draft of the Genetic Modification Project is due on Friday (10/27) by 11:59 pm.
• The cell wall is located outside of the plasma membrane and provides a durable outer layer to give structural support to the cell.