Biology Notes - Cell Structure and Function

07/04/2024, 1:15 AM Describe negative sense viruses Negative sense RNA cannot be directly translated. Instead, a complimentary strand must be synthesized in the host cell. This complimentary strand can then be translated to produce viral proteins. In order to ensure the complimentary RNA strand is s...

07/04/2024, 1:15 AM Describe negative sense viruses Negative sense RNA cannot be directly translated. Instead, a complimentary strand must be synthesized in the host cell. This complimentary strand can then be translated to produce viral proteins. In order to ensure the complimentary RNA strand is synthesized, negative sense viruses carry an enzyme called RNA replicase (RNA dependent RNA polymerase) which synthesizes the complimentary strand described previously. Describe positive sense viruses Positive sense means that the viral genome can be directly translated by the ribosomes of the host cell, just like mRNA. Describe the cell wall in gram positive cells Gram Positive cell wall's consist of a thick layer of peptidoglycan and lipoteichoic acid. GRAM NeedtomakemRNA PLUS(POSITIVE)SENSERNAGENOMES Outermembrane Lipoproteins Peptidoglycan proteins Periplasmic space (tve)sensemRNAAAA Cytoplasmic membrane Describe the cell walls in Gram Negative bacteria Gram Negative bacteria have a thin layer of peptidoglycan. They also have an outer membrane beyond the peptidoglycan which is studded with lipopolysaccharides. Note periplasmic space in diagram X Poin How do bacteria use the des Protein Electron Transport Chain without mitochondria? Do Eukaryotic cell walls have peptidoglycan? They use their own cell membrane to house the ETC enzymes. No. Peptidoglycan is only present in bacterial cell walls. file:///Users/aliaalmarri/Desktop/print.html Page 1 of 21 07/04/2024, 1:15 AM How does a lysosome digest something? How do prokaryotic ribosomes contrast with eukaryotic ribosomes? Prokaryotic ribosomes are made of a 30S and a 50S subunit, while eukaryotic ribosomes are made of a 40S and a 60S subunit. How does the environment in the nucleus compare to the environment of the rest of the cell? file:///Users/aliaalmarri/Desktop/print.html How do the concentration of organelles in different cell types vary? The concentration of organelles is different from cell type to cell type. These differences are functional. For example, cells that need a lot of energy have a lot of mitochondria. Cells that secrete a lot have high RER and Golgi Apparatus. Whether it is digesting food or unneeded organelles, the lysosome must interact with a membrane bound carrier of some sort(usually something ending in some). The lysosome will fuse its membrane with the carrier, inject its hydrolytic enzymes into the new macro structure, and digest whatever the original carrier was carrying. Lysosomes fuse with vesicles to exert their effects! How is the DNA of prokaryotic cells stored? Prokaryotic DNA exists as a single, circular molecule which floats in a region of In what 3 ways are Archaea similar to Bacteria? Page 2 of 21 07/04/2024, 1:15 AM Because the nuclear membrane is selectively permeable, the environment in the nucleus is separate and distinct from the environment in the rest of the cell. space known as the nucleoid region. The presence of the nuclear envelope permits the separation of what two steps of the central dogma of biology? In what 3 ways are Archaea similar to Eukarya? 1. Archaea start translation with Methionine like Eukarya 2. Archaea Contain similar RNA polymerases to Eukarya 3. Archaea associate their DNA with histones like Eukarya Archaea have a singular circular chromosome, divide by binary fission or budding, and share a similar overall prokaryotic structure to Bacteria. The nuclear membrane is a double membrane. Transcription and Translation What are nuclear pores? Nuclear pores allow selective two way exchange of material between the cytoplasm and the nucleus. What are cristae? What are lysosomes? Cristae are the infoldings of the inner mitochondrial membrane. These foldings increase the surface area available for electron transport chain enzymes. Lysosomes are membrane bound structures containing hydrolytic enzymes. They are found floating in the cell's cytoplasm file:///Users/aliaalmarri/Desktop/print.html Essentially, nuclear pores are the doors into and out of the nucleus. Page 3 of 21 07/04/2024, 1:15 AM What are tail fibers? What are some examples of connective tissues? Tail fibers are extensions of a bacteriophage that allow it to recognize and connect to target cells. Bone, cartilage, tendons, ligaments, fat tissue, and blood. What are the characteristics and 3 roles of Intermediate Filaments? What are the 9 main differences between Eukaryotes and Prokaryotes? Intermediate filaments are a diverse group of filament proteins, e.g. Keratin, Desmin, vimentin, and Lamin. Intermediate filaments are able to withstand a lot of tension, which makes the cell structure more rigid and is important in the overal maintenance of the cytoskeleton. Intermediate filaments also file:///Users/aliaalmarri/Desktop/print.html What are the 3 functions of the peroxisome? Because of their hydrogen peroxide, peroxisomes are important in the breakdown of long chain fatty acids (Beta Oxidation). Peroxisomes also participate in the synthesis of phospholipids and contain some enzymes for the Pentose Phosphate Pathway. What are the characteristics and 3 roles of Microfilaments? Microfilaments are solid polymerized rods of Actin. When organized into bundles and networks, Actin filaments provide resistance to compression and fracture for the cell. Actin filaments can also generate force for movement by interacting with Myosin. Finally, Actin Filaments are Page 4 of 21 07/04/2024, 1:15 AM anchor organelles to certain locations in the cell. Finally, Intermediate filaments are important in cell-cell adhesion. important for the formation of the cleavage furrow in mitosis/meiosis. This is accomplished by an actin ring which forms at the site of division between cells. The ring contracts, and the cell gets pinched into two. What are the characteristics and 3 roles of Microtubules? Microtubules are hollow polymers of Tubulin proteins. Microtubules radiate throughout the cell, providing pathways along which vesicles can travel. This is accomplished by motor proteins like Kinesin and Dynein, which travel along the microtubules and drag vesicles with them. Microtubules are also important in the structures of Cilia and Flagella. What are the characteristics of Archaea? Archaea are single-celled organisms that look like bacteria, but have genes and metabolic pathways that are more similar to Eukaryotes. What are the components of viruses? 1. Genetic Material 2. Protein Coat, also known as Capsid 3. Envelope (Optional) They were historically considered extremophiles and they are notable for their ability to employ chemosynthesis, an ability to generate energy from inorganic compounds like sulfur and nitrogen. Finally, Centrioles are composed of microtubules and use them to exert their effects during mitosis. What are the four steps of a Gram Stain? What are the four stages of file:///Users/aliaalmarri/Desktop/print.html 1. Stain the bacterium with Crystal Violet 2. Add Iodide, which binds the crystal violet and traps it in the cell. 3. Ethanol is added to disrupt the membrane and wash the crystal violet out. In Gram Positive cells, the What are the four tenets of Cell Theory? 1. All Living things are composed of cells. Page 5 of 21 07/04/2024, 1:15 AM bacterial growth? 1. Lag Phase 2. Log Phase 3. Stationary Phase 4. Death Phase thick layer of peptidoglycan will withstand the ethanol and keep the violet in. In Gram Negative cells, the thin layer of peptidoglycan will be washed away, along with the violet color. 4. The bacterium is counterstained with Safranin (Pink). 2. The cell is the basic functional unit of life. 3. Cells arise only from preexisting cells. 4. Cells carry genetic information in the form of DNA. This genetic material is passed on from parent to daughter cell. What are the functions of the epithelial tissues? What are the functions of the Centriole? What are the four tissue types? 1. Epithelial Tissue 2. Connective Tissue 3. Muscle Tissue 4. Nervous Tissue The Centriole is the organizing center for the Microtubules within a cell. Also, the centrioles play an important role in the separation of chromosomes during mitosis. Epithelial tissues cover the body and line its cavities. These tissues, being exterior tissues, provide protection against infection and dessication (drying out). In some tissues, epithelial cells are also involved in absorption, secretion, and sensation. What are the three components of bacterial flagella? 1. The Filament 2. The Basal Body (Apparatus) 3. The Hook What are the three domains of life? Eukarya, Archaea, and Bacteria What are the three forms of genetic recombination seen in Bacteria? 1. Transformation 2. Conjugation 3. Transduction file:///Users/aliaalmarri/Desktop/print.html Page 6 of 21 07/04/2024, 1:15 AM What are the three places an endosome can transport material to? 1. To and from the Plasma Membrane 2. To the lysosomes 3. To the trans-Golgi What are the three structural components of the Cytoskeleton? 1. Microfilaments 2. Microtubules 3. Intermediate Filaments What are the three shapes of bacteria? What are the three shapes of epithelium? 1. Cocci 2. Bacilli 3. Spirilli 1. Squamous 2. Cuboidal 3. Columnar What are the three types of anaerobes? What are the three types of layering found in epithelial cells? 1. Obligate anearobe 2. Facultative anaerobe 3. Aerotolerant anaerobe 1. Simple 2. Stratified 3. Pseudostratified What are the two types of Endoplasmic Reticulum? What are the two functions of the mitochondria? Rough ER and Smooth ER 1. The mitochondria file:///Users/aliaalmarri/Desktop/print.html Page 7 of 21 07/04/2024, 1:15 AM produce useful chemical energy in the form of ATP through the Citric Acid Cycle and the Electron Transport Chain What are the two types of bacetrial cell wall? 1. Gram Positive 2. Gram Negative 2. Mitochondria can induce apoptosis by releasing Electron Transport Chain enzymes. What color do Gram Positive and Gram Negative bacterium appear after Gram Staining? What are the two types of single stranded RNA viruses? Positive - Purple Negative - Pink What does it mean for a bacterium to be bacilli? Bacilli bacteria are shaped like rods. 1. Positive Sense 2. Negative Sense What does it mean for a bacterium to be cocci? Cocci bacteria are shaped like small spheres. What does it mean for a bacterium to be spirilli? Spirilli bacteria are shaped like long thin spirals What does it mean that mitochondrion are semiautonomous. It means that mitochondrion can do a couple of functions on their own independently from the cell. These functions are below. 1. Mitochondria contain some of their own genes (in the form of cicular DNA strands) and have their own ribosomes (That are similar file:///Users/aliaalmarri/Desktop/print.html Page 8 of 21 07/04/2024, 1:15 AM in size to prokaryotic ribosomes!) 2. Mitochondria can divide independently of the cell as a whole (by performing binary fission). What does it mean to be Columnar Epithelium? Columnar Epithelium is composed of long, thin, column shaped cells. What does it mean to be a eukaryotic cell? Eukaryotic cells are cells that have nuclei and membrane bound organelles. What does it mean to be Cuboidal Epithelium? What does it mean to be Squamous Epithelium? Cuboidal epithelium is composed of cube shaped cells. Squamous epithelial cells are flat, scale like epithelial cells. What does it mean to be a female bacterium? The female bacterium is F-, meaning it does not have a sex factor plasmid. Female bacteria accept the conjugation bridge and genetic info from the donor male. What does it mean to be a male bacterium? The male bacterium is the bacterium that has an F+ plasmid and therefore can construct a conjugation bridge. What does it mean to be pseudostratified epithelium? What does it mean to be a prokaryotic cell? Prokaryotic cells are cells that have no nuclei. file:///Users/aliaalmarri/Desktop/print.html Pseudostratified epithelium cells appear to be stratified, but are actually all attached to a basement membrane, like simple epithelium cells. What does it mean to be simple epithelium? Simple epithelium is epithelium that consists of a single layer. Page 9 of 21 07/04/2024, 1:15 AM What does it mean when we say epithelial cells are polarized? What does it mean to be stratified epithelium? Stratified epithelium consists of multiple layers. Because epithlelial cells cover the body and line its organs, one side of an epithelial cell will be attached to underlying structural cells and the other side will be exposed to the lumen of an organ or the outside world. Because of these dramatically different environments, the two sides of the epithelial cell are actually pretty different. We call this phenomenon polarization. What happens if a lysosome releases its enzymes? If a lysosome releases its enzymes, the enzymes will begin to break the cell down from the inside out in a process known as autolysis. What is Binary Fission? Binary fission is a simple form of asexual reproduction seen in prokaryotes. The prokaryote copies its genetic information and then splits into two. file:///Users/aliaalmarri/Desktop/print.html What is a bacteriophage? Bacteriophages are viruses that specifically target bacteria. What is a capsid? Capsid is another name for the protein coat in a virus. Page 10 of 21 07/04/2024, 1:15 AM What is a centriole? A centriole is a hollow structure composed of nine triplets of microtubules. What is a centrosome? What is a chromosome? A centrosome is the region of the cell where the centrioles are found. A chromosome is a DNA molecule with some or all of the genetic information of a cell. What is a cilia? Cilia are projections from a cell that are involved in movement of materials along the cell's surface. For example, cilia in the respiratory tract will undulate in order to move mucus. file:///Users/aliaalmarri/Desktop/print.html What is a flagella? What is a facultative anaerobe? Facultative anaerobes are bacteria that can switch between anaerobic and aerobic metabolism depending on the environment. Flagella are structures involved in the movement of the cell itself. They achieve this by spinning and flailing, generating force for movement. Page 11 of 21 07/04/2024, 1:15 AM What is a mitochondrion? What is a histone? A histone is a protein in the nucleus around which Eukaryotic DNA winds. This helps organize the DNA. What is a peroxisome? A peroxisome is a single membrane bound organelle containing Hydrogen Peroxide. This Hydrogen Peroxide is generated with the help of a crystalline core. What is a lumen? A lumen is the inside space of any hollow tubular structure. What is a plasmid? Plasmids are small pieces of circular DNA, usually acquired from the environment. Plasmids don't carry critical genetic information, but can sometimes carry genes that provide the bacterium an evolutionary advantage, e.g. antibiotic resistance. A mitochondrion is a double membraned organelle with structures in its inner membrane that allow it to generate ATP. What is a provirus or prophage? A provirus or prophage is a latent piece of viral genome that has been integrated into the host's genome. What is a retrovirus? Retroviruses are enveloped single stranded RNA file:///Users/aliaalmarri/Desktop/print.html What is a sex (F) factor? What is a sex pilus? Page 12 of 21 07/04/2024, 1:15 AM viruses that carry an enzyme called reverse transcriptase. This enzyme synthesizes DNA from RNA, which gets integrated into the host genome. HIV is the most famous retrovirus. A sex factor is a plasmid that allows bacterium to form sex pili with which they can conjugate to other bacteria. Sex pili are appendages that male bacteria use to form conjugation bridges. What is a tail sheath? The tail sheath is the long thin part of a bacteriophage. The tail sheath can act like a syringe, injecting the genetic info into the bacterium. What is a virulence factor? A virulence factor is a plasmid that specifically makes the bacterium more pathogenic. What is a transposon? Transposons are genetic elements that are capable of inserting and removing themselves from the host genome. What is a vesicle? Vesicle is the umbrella term for small membrane bound sacs. Lysosomes, endosomes, exosomes, etc. are all examples of vesicles. What is an Aerotolerant anaerobe? What is an anaerobe? Aerotolerant anaerobes are bacteria that cannot use oxygen in metabolism, but are not harmed by its presence in the environment. An anaerobe is any bacterium that doesn't need oxygen to survive. What is an endosome? file:///Users/aliaalmarri/Desktop/print.html Page 13 of 21 07/04/2024, 1:15 AM An endosome is an endocytic vesicle that pinches off from the membrane during endocytosis. What is an episome? An episome is a plasmid that can integrate itself into the host bacterium's genome. What is an obligate aerobe? An obligate aerobe is a bacterium that requires oxygen to survive. What is an organelle? What is an obligate anaerobe? An obligate anaerobe is a bacterium that dies in the presence of oxygen and therefore needs a nonoxygen environment to survive. What is bacterial conjugation? Conjugation is when a bacterium forms a conjugation bridge with another bacterium and shares genetic information (including the sex factor, so the recipient can then form file:///Users/aliaalmarri/Desktop/print.html An organelle is any specific sub unit within the cell that has a specialized function. These functions range from generating energy, protecting the cell, digesting things, transporting stuff, etc. What is apoptosis? Apoptosis is intentional/programmed cell death. This is a cell dying because it was told to die and it listened, not because it was just randomly killed. What is bacterial transduction? Transduction is when a virus accidentally traps the genetic information of one bacterium in itself and then incorporates that genetic information into the genome of another What is bacterial transformation? Transformation is when a bacterium picks up foreign genetic material and Page 14 of 21 07/04/2024, 1:15 AM a bridge with new bacteria). bacterium. integrates it into its own genome. What is exocytosis? What is chemotaxis? The ability of a cell to detect and move towards or away from chemical stimuli. What is rough ER and what is its function? Rough ER is ER studded with ribosomes. These ribosomes take in ingredients from the cytosol, but secrete their proteins directly into the lumen of the ER. This is the function of the ER, and believe it or not, being able to make proteins that are file:///Users/aliaalmarri/Desktop/print.html Exocytosis is when material is packaged into a secretory vesicle, the secretory vesicle fuses with the plasma membrane, and the contents of the secretory vesicle are released outside of the cell. What is parenchyma and of which tissue type is it usually comprised? Parenchyma are the functional parts of an organ. For example, nephrons in the kidney or acid producing cells in the stomach. The parenchyma is usually made up of epithelial cells. What is smooth ER and what are its 3 functions? Smooth ER is ER that takes on a tubular form and has no ribosomes in its membrane. What is the Cytoskeleton? The Cytoskeleton is a large network of 3 structural components that provides shape and structure to the cell. These structural Page 15 of 21 07/04/2024, 1:15 AM protected from the cytosol is actually pretty useful. These Rough ER Proteins are usually sent to the Smooth ER where they will be packaged and sent to the Golgi Apparatus. What is the Endoplasmic Reticulum? (ER) The Endoplasmic Reticulum (ER) is a series of interconnected membranes that are contiguous with the nuclear envelope. file:///Users/aliaalmarri/Desktop/print.html components also serve as paths by which things can be transported to various locations in the cell. Smooth ER is where lipids are synthesized (for example the phospholipids in bilayers and steroids). Smooth ER also detoxifies certain drugs and poisons. Finally, proteins that were synthesized into the Rough Endoplasmic Reticulum travel to the Smooth ER so they can be packaged and transported to the Golgi Apparatus. What is the Golgi Apparatus' function? The Golgi Apparatus' function is to receive materials from the ER and modify these materials by adding various functional groups. These functional groups serve to both modify the function of the materials and to direct them to certain locations in the cell. Once the material has been modified and has a location-determining functional group, the material will leave the Golgi Apparatus in an appropriate vesicle and travel to its intended location. This intended location can be inside the What is the Golgi Apparatus? The Golgi Apparatus is a series of stacked membrane bound sacs inside of the cell. Page 16 of 21 07/04/2024, 1:15 AM cell, outside the cell, or back to the Endoplasmic Reticulum. What is the Lysogenic cycle? What is the Lag Phase? What is the Log Phase? The lag phase is when the bacteria are adapting to the environmental conditions. The Log Phase is when the bacteria have adapted to the environment and start to grow exponentially. The lysogenic cycle is another way bacteriophages can spread. In the lysogenic cycle, the bacteriophage incorporates itself into the host genome. As the host replicates, the bacterial DNA replicates with it, and each daughter cell will carry the information to make viruses. What is the Lytic cycle? The Lytic cycle is one way bacteriophages can spread. In the Lytic cycle, the cell's machinery is hijacked to produce new viruses. The viruses accumulate, destroy the cell, and spread to new cells. Viruses in this cycle are said to be Virulent file:///Users/aliaalmarri/Desktop/print.html What is the basal body? What is the bacterial flagellum filament? The filament is a long hollow helical structure composed of flagellin. The basal body is a complex structure that anchors the flagellum to the membrane and provides the motor force necessary to activate the flagellum. Page 17 of 21 07/04/2024, 1:15 AM What is the basement membrane? The basement membrane is an underlying layer of connective tissue to which groups of epithelial cells will be attached. This is so the epithelial cells stay close together and can remain a cohesive unit. What is the cell envelope? The cell envelope is the name for all of the layers of the cell extending outward from the membrane. For example, in bacteria with a cell wall and a capsule, the envelope would be the membrane, the cell wall, and the capsule. What is the cell wall? What organisms have them? The cell wall is a rigid structure that forms the outer barrier of the cell. Cell walls are found in almost all prokaryotes and in certain Eukaryotes (plants, algae, fungi). In bacteria without a capsule, the envelope refers just to the membrane and the cell wall. What is the extracellular matrix? What is the death phase? The death phase is when the bacteria have completely consumed nearby resources and begin to quickly die out due to starvation. file:///Users/aliaalmarri/Desktop/print.html The extracellular matrix is a vast collection of extracellular molecules secreted by cells that provide structural and biochemical support to the individual cells within a tissue. The extracellular matrix allows cells to associate and communicate with one another without being directly attached. What is the function of connective tissue? Connective tissue's function is to support the body and provide a framework for the epithelial cells to carry out their function. Connective tissue cells also secrete the various molecules that make up the extracellular matrix, such Page 18 of 21 07/04/2024, 1:15 AM as collagen and elastin. What is the function of lysosomes? To digest both foreign material that has been brought into the cell and damaged/uneeded organelles. also degrades misfolded proteins What is the function of the mitochondria's outer membrane? The mitochondrial outer membrane serves as a selective barrier between the cytosol and the inner environment of the mitochondrion. What is the hook? The hook connects the filament and the basal body in order to facilitate the motion in the filament that propels the bacterium forward. What is the nucleolus? What is the intermembrane space? The space between the outer and inner membrane of the mitochondrion. What is the mitochondrial matrix? The mitochondrial matrix is the space inside the mitochondrion's inner membrane. The nucleolus is a structure in the nucleus that synthesizes ribosomal RNA (rRNA). It appears as a large dark spot in the nucleus. What is the order of taxonomy from most general to most specific? file:///Users/aliaalmarri/Desktop/print.html Page 19 of 21 07/04/2024, 1:15 AM Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species. What is the nucleus? The nucleus is the control center of the cell. The nucleus is a region of space within the cell that is surrounded by a double membrane envelope. This region houses all of our genetic information and machinery. What is the shared structure of flagella and cilia in eukaryotic cells? The 9 + 2 structure, which is 9 doublets of microtubules surrounding a central doublet. MNEMONIC: Kids Play Cod On Fuzzy Green Sofas What is the restriction on bacterial conjugation? F+ Bacteria can only conjugate to F- Bacteria. F+ Bacteria cannot conjugate with other F+ Bacteria. What is the stationary phase in bacterial growth? The stationary phase is when the bacteria have reduced resources to the point where they are starting to run out and can no longer grow as quickly. What is the stroma and of which tissue type is it usually composed? The stroma is the support structure of an organ upon which the parenchyma depends. It is made of connective tissue. file:///Users/aliaalmarri/Desktop/print.html Page 20 of 21 07/04/2024, 1:15 AM What is viral lysis? What is viral extrusion? Viral extrusion is when a virus leaves a cell by exocytosis instead of just killing the cell. Viruses using this are in Productive cycle Viral lysis is when a virus kills the host cell. The host cell spills out its contents, including the virus, which goes off to infect new cells. Disadvantage because cell can't make any more virions What kind of genetic information can viruses carry? Basically any kind. The genetic info in viruses can be linear or circular, DNA or RNA, and single stranded or double stranded. What kinds of proteins are usually found in the Rough ER? Proteins that are destined for secretion or proteins that are destined for integration into a membrane. file:///Users/aliaalmarri/Desktop/print.html Page 21 of 21