Cellular Transport PDF

CELLULAR TRANSPORT 2. Hypertonic Solution → Has a stronger tendency to cause Passive Transport water movement fro...

CELLULAR TRANSPORT 2. Hypertonic Solution → Has a stronger tendency to cause Passive Transport water movement from another The movement of substances across membranes solution. without the use of energy.- → * If a cell is placed in this type of Diffusion- the net movement of solute solution, it will shrink because water substances from an area of higher concentration of the cytoplasm will be drawn out to an area of lower concentration normal Molecules move HIGH to LOW concentration no solute concentration is higher than need of energy that inside the cell, water leaves the For example: If you spray air freshener in a cell, causing it to shrivel and die. certain part of your room, you will notice that the o flaccid air freshener you just sprayed will slowly diffuse o The water moves out, causing the or spread to other parts of the room. This plasma membrane to pull away from happens because the molecules of the air the cell wall and the to wilt or freshener diffused from the higher concentration plasmolyze (plasmolysis) (the area where you sprayed) to areas of lower 3. Isotonic Solution concentration in the room. → Two solutions that have equal OSMOSIS amounts of water and solutes. The diffusion of water molecules across → * If a cell placed in this type of a selectively permeable membrane solution, it can maintain its The process where solvent molecules equilibrium; therefore, there will be such as water move from region of less no change in the cell concentrated solutions (hypotonic lysed solution) to a region of more Cells survive wherein the solute concentrated solution (hypertonic concentration is equal to that inside solution) through selectively permeable the cell. membrane. o turgid When these two regions have equal o There is no net gain of water, the concentrations of solute )their solutions plant cells lose their turgor have a equal concentrations), the water pressure—the pressure exerted by molecules will stop moving. the cell membrane against the cell OSMOTIC SOLUTIONS wall due to water intake. Without 1. Hypotonic Solution this pressure, the cells become → Has a lower tendency to gain water flaccid, and the plant may wilt from the another solution. because the cells are not firm → If a cell is placed in this type of enough to support the plant's solution, water will enter the cell, structure causing it to bulge or become turgid FACILITATED DIFFUSSION and could lead to cell rupture Another form of passive transport. Shriveled It is the movement of solutes through Concentration lower than inside the protein channels down the cell concentration gradient without energy Harmful to a living cell expenditure o Plasmolysed Water and certain hydrophilic (water o The inward movement of water loving) solutes cross the membrane builds up the turgor pressure of the cell, and the cell then become very firm 1. Carrier Proteins’  Change in shape, which is triggered by Sodium (Na+): The pump kicks out the binding and release of a substance it sodium ions from inside the cell to the transports outside. This is important because too 2. Channel Proteins much sodium inside the cell can make it → Open and close as they respond to swell and not work properly stimuli. Potassium (K+): At the same time, the → Some channel proteins open and pump brings in potassium ions from the close when specific substance, other outside to the inside of the cell. than the substance to be Potassium helps the cell perform its transported binds to the channel functions, like sending signals in nerves and muscles Active Transport Energy: The pump uses energy (from a Uses energy in moving solutes across a molecule called ATP) to do this job. It membrane by moving up the concentration works against the natural flow of these gradient ions, which is why energy is needed Carrier protein – A process requires the So, the Sodium-Potassium Pump keeps expenditure of energy through transport the right balance of sodium and proteins. potassium inside and outside of the cell, The movement in active transport across making sure the cell stays healthy and membranes is unidirectional. functions correctly. LOW to HIGH concentration need ATP Bulk Transport Water and small solutes enter and leave Essential to the cell mainly for THREE reasons: the cell through passive and active 1. It enables the transport of nutrients to diffusion. However, large molecules, the cell even when the concentration on such as polysaccharides cross the inside is already higher. \ membranes in bulk through the 2. It makes the removal of waste materials processes of exocytosis and endocytosis from the cell possible despite the higher 1. Exocytosis concentration outside the cell 3. It enables the cell to maintain the → rocess of removing materials concentration of essential ions such as from the cell through the K+, Na+,Ca2+, and H+ vesicles that fuse with the Sodium-Potassium Pump plasma membrane, thus, Molecules move against the subsequently releasing their concentration gradient. It involves the contents outside the cell.- use of energy through ATP hydrolysis → Common when a cell has to wherein ATP is hydrolyzed to ADP. secrete substances for export.- The enzyme Na+/K+- ATPase involved. → An example is the secretion of This is necessary to maintain greater digestive enzymes from the amounts of Na+ ions outside the cell epithelial cells of digestive membrane and greater amounts of K+ organs to the food passing ions inside the cell through the digestive system This unbalanced charge transfer is 2. Endocytosis necessary in the performance of action → The reverse process of potential, particularly in nerve cells. The exocytosis wherein cells engulf whole process helps maintain the materials concentration of essential ions in the cell → A substance outside the cell is captured when the plasma membrane merges with that substance and engulfs it.  → The engulfed substance then The length is responsible for the difference enters the cytoplasm while it is between fast dividing cells and slowly enclosed in a vesicle. dividing cells. → Happens either phagocytosis or pinocytosis. Slowed down by reducing the nutrients available in the cell; thus the cell will take longer to build Phagocytosis up the resources needed for cell division. “cellular eating” the cell grows and gathers nutrients. It also The most common form of endocytosis.- Occurs makes proteins and organelles needed for later when dissolved material enters the cell. stages, getting ready for DNA replication. The plasma membrane wraps around the solid 2. SYNTHESIS (S) STAGE material and engulf Very crucial part because this is the time This describes how single-celled protists (e.g., when DNA is synthesized. Amoeba)capture food. Begins with the replication of cellular DNA. “Another example is how white blood cells engulf When DNA has been replicated, the cell bacteria has twice as many chromosomes as Pinocytosis before; it is then ready to move to the G2 stage. “cellular drinking” DNA synthesis is the process where the Occurs when dissolved substances enter the cell makes an exact copy of its DNA. cell. - During the Synthesis (S) stage of Like phagocytosis, the plasma membrane wraps interphase, the cell copies its DNA so around the material and forms a vesicle that that each new cell will have a complete contains the engulfed material set after division. “For example, the human egg cell’s uptake of 3. GAP 2 (G2) STAGE nutrients from its surroundings Comes after DNA synthesis. The cell synthesizes more proteins needed for mitosis. CELLULAR REPRODUCTION During this stage, proteins necessary for cell division, such as kinase and histones, INTERPHASE are synthesized including microtubules Longest phase in the cell cycle. that will comprise the spindle fibers. The cell prepares for cell division. The chromosomes start to condense and Taking in nutrients and growing. become visible, and the cell enters Interphase is the longest phase in the cell cycle prophase, the first phase of mitosis. because the cell spends this time getting ready to In Gap 2 (G2) phase, the cell continues to divide. grow, makes final preparations, and It uses the nutrients to build new cell parts, make checks for any DNA errors before proteins, and copy its DNA. dividing. "Condense" means to make something Stages of Interphase more compact or concentrated. 1. GAP 1 (G1) STAGE THE CELL CYCLE VARIES AMONG CELLS First stage that comes before the synthesis of DNA. Some embryo cells can complete the cycle in 20 Cell increases in mass and/or size and the minutes. organelles increase in number in preparation Fruit fly lasts only eight minutes. for cell division.  ▪ Simply pass the G1 and G2 stages, and One of the important external regulators is the the whole period id divided between S growth factor that stimulate the growth and and M stages. division of cells. Mammalian cell spends more or less 24 hours to Cell growth and division are needed in healing complete the cycle. wounds and embryonic development. ▪ More time is spent for growth during Chemical balance, particularly involving the interphase (G1, S & G2). It only takes molecules like growth factors, nutrients, only around 24 hours to stay at the hormones, and ions. mitosis (M) phase of the cycle. ❖ Growth Factors: Stimulate cell division. Most often, cells atop in G1 before DNA ❖ Hormones: Promote cell growth and division. replication and enter the Go stage or the resting ❖ Cytokines: Regulate immune cell division and stage, where cells may stay at this stage for days inflammation. to years before proceeding to cell division. ❖ Contact Inhibition Proteins: Prevent Most of the time, cells in the body are in G0 overcrowding by stopping cell division when cells phase, such as muscle cells and nerve cells, and touch. may even remain in this stage permanently, ❖ Adhesion Molecules: Influence cell division while liver cells may resume the cycle as the based on cell attachment. need arises. ❖ Inhibitory Factors: Halt division in response to The G0 phase is a resting stage where the cell stress stops dividing and performs its regular functions. ❖ Nutrient Availability: Ensures cells only divide Some cells stay in this phase permanently, while when sufficient resources are present. others can re-enter the cell cycle later. CELL CYCLE CHECKPOINTS REGULATING THE CELL CYCLE - checkpoints in interphase refer to specific PROTEINS THAT HELP REGULATE THE CELL CYCLE: control mechanisms within the cell cycle that ensure the cell is ready to proceed to the next a) Internal regulators phase. Proteins found inside the cell. - Checkpoints in cell division are like quality Regulates the processes that happen inside the control stations. They ensure that a cell is cell. dividing correctly and only when it's safe to do Include proteins that make sure that mitosis does so. not occur unless the chromosomes have - "Adequate" means enough or sufficient to meet replicated. a need or requirement. ❖ Cyclins and CDKs: Drive the cell cycle forward by activating specific processes at each stage. 1. G1/S CHECKPOINT ❖ Tumor Suppressors (e.g., p53): Prevent Checks for the size of the cell, nutrient uncontrolled cell growth by repairing DNA or levels available and needed for cell initiating cell death. division, cues from outside the cell, as ❖ Checkpoint Proteins: Monitor DNA integrity and well as the integrity of its DNA. pause the cycle for repairs if needed. Cells that do not reach their adequate ❖ APC/C: Ensures correct chromosome separation size or those that have DNA damage during mitosis. arrested, unless they are corrected. ❖ Mdm2: Regulates p53 levels, allowing cell cycle Normal cells allowed to proceed to the arrest or apoptosis in response to DNA damage. next cell cycle phase. b) External regulators 2. G2/M CHECKPOINT Proteins or molecular signals that respond to The checkpoint prior to mitosis. events outside the cell. It checks the integrity of the DNA and Examples of these outside events are chemical any replication damage. balance and sufficient nutrients of the cell.  DNA damage due to replication is - During interphase, the DNA has been replicated. corrected and repaired. Thus once the DNA has condensed into Cells that have irreparable DNA damage chromosomes during the prophase stage, the goes to apoptosis or cell death. total will be 92 chromatids or 46 double- Apoptosis is a natural process of stranded chromosomes composed of two sister programmed cell death in which cells chromatids. self-destruct in a controlled manner. This process is essential for maintaining the health of an organism by removing damaged, unnecessary, or potentially harmful cells. Unlike necrosis, which is a form of cell death caused by injury or disease and leads to inflammation, PROPHASE apoptosis is a clean and orderly process that helps with development, immune More chromosomes form from the chromatin. function, and tissue maintenance. Spindles appear at the opposite poles of the cell, 3. M CHECKPOINT while the nuclear envelope disappears. The checkpoint that happens during The nucleolus disappears. mitosis, particularly during the The chromatin fibers coil become chromosomes. metaphase stage. The resulting chromosomes have two It ensures that all of the chromosomes chromatids which are fused together at the are attached to the spindle in centromere. preparation for anaphase. The centrosome (the area where microtubules Wrong alignment and attachment are are produced) divides into two, each attached irreversible, so mitosis is halted unless pair of centrioles. strayed chromosomes are captured by The centrioles travel to the “poles” and form the spindle fibers. mitotic spindles. "Irreversible" means something that - In animal cells, these spindles appear around the cannot be undone or changed back to its centrioles as structures called aster. original state. In late prophase, the cell membrane has totally disintegrated and the cell is now ready to enter metaphase. CELL DIVISION: MITOSIS AND MEIOSIS In this stage, 46 double-stranded chromosomes equivalent to 92 chromatids are present. MITOSIS In prophase, the chromosomes become visible, Initiated after the completion of interphase (G1, the nuclear membrane breaks down, and the S, and G2). spindle fibers start to form. Takes place for only a short period of time. METAPHASE To understand how the chromosomal number of the parent cell is maintained in mitosis, the Characterized by the full development of the human chromosomal number (46 single- spindle fibers. stranded chromosomes) will be used. The chromosomes also align at the equatorial Mitosis is the process where a cell divides to plane. create two identical cells, each with the same The centrioles can be found at the center of the number of chromosomes as the original cell. cell. The chromosomes change position until they Replication of a chromosome (S phase- Mitotic phase connect to the fibers coming from both sides of the centromere.  There are still 46 double-stranded chromosomes o Contains two nuclei formed. because the sister chromatids have not o Separates the organelles and other separated yet. macromolecules such as ribosomes, ER, , the chromosomes line up in the middle of the Golgi bodies, and mitochondria. cell, and spindle fibers attach to them. o * In some cases, the two new cells formed are equal in size. ANAPHASE o Cytokinesis is the process during cell Characterized by the separation of the division in which the cytoplasm of a chromosomes. single eukaryotic cell is divided into two The chromosomes are pulled toward the cell’s daughter cells. opposite poles. o In telophase, the chromosomes reach The spindle fibers, which are not attached to the the opposite sides of the cell, and new chromatids, elongate the cell. nuclear membranes form around them. The centromeres in each chromosome begin to separate. The sister chromatids separate from each other MEIOSIS and are now considered a “full” chromosome. Takes place in sexually mature organisms. The spindle pulls the daughter chromosomes to Process that results in the reduction of the each pole at the opposite ends of the cell. chromosome number from diploid to haploid in At this stage ends, the two poles of the cell also germ cells ( the egg cell and sperm cell). move apart, each containing a complete set of Produces gametes that only have one haploid or single-stranded chromosomes. half of the set of chromosomes. There are now 92 single stranded chromosomes, Divided into meiosis I (reduction division) and with 46 chromosomes at each pole. meiosis II with a short phase between the two the chromosomes are pulled apart to opposite called interkinesis. sides of the cell. Interphase occurs before the actual meiotic TELOPHASE cycle. Meiosis is the process that creates four unique The complete sets of chromosomes during sex cells (sperm or eggs) with half the number of telophase are condoned off into new distinct chromosomes as the original cell. nuclei of the daughter cell. The polar spindle fibers continue lengthen, and the nuclei are prominent along the opposite poles. The two nuclear envelopes of the two nuclei start to reappear. They were derived from the parent cell’s nuclear envelope and pieces of the endomembrane system. The nucleolus also starts to reappear in each cell. Chromatin fibers of chromosomes uncoil. The cell finally divides into two new cells, each bearing 46 single-stranded chromosomes like the parent cells. Cytokinesis o Happens during telophase. o It occurs when the cytoplasm from the original cell divides and forms two new cells.  MEIOSIS I The homologous pairs of chromosomes remain together. PROPHASE I The spindle fibers increase in number at attach The nuclear membrane and the nucleolus starts to the kinetochore of each chromatid to facilitate to disappear. movement. The cell shows visible chromosomes that are paired chromosomes line up in the middle of the already replicated during interphase. cell. The spindle fibers become visible. ANAPHASE I Each chromosomes is composed of two sister chromatids held together by a centromere and is The homologous pairs of chromosomes (dyad) called a dyad. separate and migrates towards their respective In prophase I of meiosis, chromosomes pair up poles. with their counterparts, and crossing over The sister chromatids still remain attached at occurs, where they exchange genetic material. their centromere and move together toward the Characterized by synapses or pairing of poles. homologous chromosomes. Still, at this stage, there are 46 double-stranded Same length, staining pattern, and position of chromosomes, which is equivalents to 92 the centromere. chromatids. Carry same genes but different alleles or type: the paired chromosomes are pulled to opposite one comes from the father, while the other from sides of the cell. the mother. TELOPHASE I Example: eye color In prophase I of meiosis, chromosomes pair up The two daughter cells are completely divided. with their counterparts, and crossing over The number of chromosomes in both cells is the occurs, where they exchange genetic material. same. Crossing over takes place between two non- A nuclear envelope and nuclei reappear, and the sister chromatids (one from the father, one for chromosomes become less visible. the mother) along a point called chiasma How many number of chromosomes and (chiasmata); the two other chromatids remain chromatids at this stage? uncrossed. 46 chromosomes and 92 chromatids A pair of homologous chromosomes is composed In telophase I of meiosis, the cell splits into two, each with a set of chromosomes. of four sister chromatids called tetrad. This crossing over results in genetic recombination and accounts for genetic variation. MEIOSIS II Plural-chiasmata - Meiosis II is similar to mitosis; it divides each of In prophase I of meiosis, chromosomes pair up the two cells from meiosis I into two new cells, with their counterparts, and crossing over resulting in a total of four unique sex cells. occurs, where they exchange genetic material. For example: Prophase II - For human sex cells, the number of double ❖ The nuclear envelope and nucleoli disappear, stranded chromosomes at this stage is 46, which and the chromatids start to shorten and thicken. is equivalent to 92 chromatids. ❖ The centrioles move to opposite poles, and the METAPHASE I spindle fibers arrange in preparation for the The paired homologous chromosomes (tetrads) coming metaphase. are moved by the spindle fibers to the equator of ❖ There are 23 double-stranded chromosomes, the cell. which equivalent to 46 chromatids.  ❖ , chromosomes become visible again in each of GAMETOGENESIS the two cells, and the nuclear membranes break The process where diploid cells undergo cell down. division and differentiation through meiosis to METAPHASE II form mature haploid gametes or sex cells. Usually takes place in the reproductive organs of ❖ Characterized by the movement of the body. chromosomes to the equator. process of creating sperm and egg cells, which ❖ Each chromosomes is composed of two sister are used for reproduction. chromatids that are joined by a centromere and SPERMATOGENESIS are attached to the spindle fiber. The process of sperm formation. ❖ chromosomes line up in the middle of each of A hormonally controlled process that begins in the two cells. males at the age of puberty. Inside the testes are numerous thin and tight coiled seminiferous tubules with immature cells ANAPHASE II called spermatogonia which develop into ❖ Centromeres joining the chromatids divide, mature sperm cells as the process goes on. allowing microtubules to attach to the Sertoli cells that abound along the inner walls of kinetochore to pull the sister chromatids apart. the tubules help nourish the immature germ ❖ The sister chromatids are no called sister cells by providing them nutrients and blood chromosomes as they move to the opposite products. poles. Spermatogenesis is the process of producing ❖ the chromosomes are pulled apart into sperm cells in males. individual chromatids, moving to opposite sides Puberty is the stage of life when a person’s body of each cell. changes and develops into an adult, capable of reproducing. It involves physical, hormonal, and TELOPHASE III emotional changes. ❖ As the spindle fibers dissolve, a nuclear The testes are the male reproductive organs that membrane forms around the chromosomes produce sperm and hormones like testosterone. uncoil and lengthen. As the mature cells develop into primary ❖ The cleavage furrow eventually produces a total spermatocytes, secondary spermatocytes, of two daughter cells, each with haploid set of spermatids, and finally into sperm cells, they are chromosomes. transported closer to the lumen of the ❖ A total of four (4) new cells haploid seminiferous tubules, and into the epididymis. chromosomes are produced. A haploid chromosome number is 22 autosomal ❖ How many chromosomes and chromatids does chromosomes (chromosomes other than sex each cell carry? chromosomes) and one sex chromosome, either ❖ 23- chromosomes and 23 chromatids. the X or the Y chromosome. ❖ In telophase II, new nuclear membranes form around the separated chromatids in each of the four cells, completing meiosis. OVOGENEIS/OOGENESIS DISEASE ASSOCIATED WITH ABNORMAL CHROMOSOME NUMBERS ❖ The process of egg formation. ❖ At the start of puberty takes place. 1. DOWN SYNDROME ❖ Inside the ovaries are primordial cells called May affect male and female. oogonia. Caused by an error in the process of ❖ These mature and develop into primary oocytes, meiosis. secondary oocytes, ootids, and finally into an Has an extra orpartialchromosome21 ovum or egg cell. This happens when homologous ❖ As the process continues, the chromosome chromosomes do not separate properly number of the original primordial cell is reduced (nondisjunction) during the process of to half of the original number, thus making the meiosis. cell haploid after the whole process. Happened in chromosome 21(Trisomy). ❖ 22 autosomal chromosomes and one sex Causes problems in brain and physical chromosome, the X chromosome. development as the child grows Physical features are a flattened face along the nose bridge area, a short neck, small ears, stunted height, small hands and feet, a tongue that tends to stick out of the mouth, and almond eyes, among others 2. TURNER SYNDROME Only effects female and is rare. Also caused by an error in the process of meiosis Lacks one chromosome. Has an XO chromosome, which means, DISEASE ASSOCIATED WITH THE CELL CYCLE they inherit only a single or partial X MECHANISM chromosome Experiences developmental problems. 1. CANCER Short, underdeveloped, and sterile A disease characterized by the females. uncontrolled division of cells.- Short fingers and toes, low set hairs, P53gene-culprits in cancer.- and a low hairline, among others o DNA damage is irreparable, p53 Puberty does not occur and their directs the cell to kill itself. secondary sex characteristics do not When cancer cells invade nearby normal develop. tissues or spread through the walls of Do not experience a menstrual cycle lymph vessels, they begin to infect other Diagnosed even before birth, during cells infancy, or early childhood in some Metastasis- the process by which cancer 3. KLINEFELTERSYNDROME cells spread from where they originated. Found only in males. o Cancer cells that have began to Having an extra X chromosome. metastasize invade other healthy cells, even tissues, Has XXY OR XXXY chromosomes ( XXY eventually depriving healthy syndrome). organs their nutrients and Undeveloped, sterile males, with some inflicting damage that is enough breast development. to be fatal. Slow learners but are not mentally retarded  Testicles and the penis are smaller than average 4. MARFANSYNDROME Cause: Genetic disorder affecting connective tissue. Symptoms: Tall stature, long limbs, heart problems, and eye lens dislocation. 5. TOURETTE SYNDROME Cause: Neurological disorder, possibly genetic. Symptoms: Involuntary vocalizations. tics and 6. ASPERGER SYNDROME Cause: Previously considered part of the autism spectrum, but now categorized under Autism Spectrum Disorder (ASD). Symptoms: Difficulties in social interactions and nonverbal communication, alongside restricted and repetitive behaviors.. 7. RETT SYNDROME Cause: Genetic mutation in the MECP2gene Symptoms: Loss of motor skills and speech, primarily affecting girls 8. GUILLAIN-BARRE SYNDROME Cause: Immune system attacking the nervous system, often after an infection. Symptoms: Weakness and tingling in the limbs, which can progress to paralysis 9. WILLIAMS SYNDROME Cause: Deletion of genetic material from chromosome7 Symptoms: Intellectual disability, cardiovascular problems, and a distinctive cheerful demeanor 10. CRUSHING’S SYNDROME Cause: Prolonged exposure to high cortisol levels. Symptoms: Weight gain, thin skin, high blood pressure, and a round face.  CELL THEORY: THE UNIFYING FOUNDATION OF CELL Blood Cell BIOLOGY - Can change shape, helping them digest and ROBERT BROWN kill disease causing germs that invade the Botanist body 1820s, he first observed the spherical structure Leaf cell in plant cells.- “nucleus” More ball-shaped THEODORE SCHWANN A single leaf cell may be designed to simply Zoologist photosynthesize, or create sugars from the He discovered the presence of cells in animal energy in light tissues Pollen cell MATTHIAS SHLEIDEN Botanist Round, ovule, triangular, disc or in a bean-shape He concluded that all plant tissues are composed with a smooth to spiky texture. of cells Used for transferring haploid male genetic RUDOLF VIRCHOW material from the anther of a single flower to the Physician by profession stigma of another in cross-pollination He studied the growth and development of cells Sperm cell and discovered that all cells arise from pre- existing cells. oval head with a long tail TENETS/POSTULATES: Provides half of the genetic material needed to form a fertilized zygote or embryo during sexual a) Cells are the smallest unit of life. All living things reproduction with an egg in the female body are composed of one or more cells. b) Cells are the basic unit of organization of all INTERNAL ORGANIZATION organisms. For example, a plant and animal cell. c) Cells come from preexisting cells. These two cells show great variations in parts Two additional key points: because they function differently to perform specific task. a) Cells carry and pass on the offspring heredity For example, glandular cell. units during cell division Produces secretory materials such as mucus b) All cells are relatively the same in terms of and hormones, which is why they are chemical composition and metabolic activity. provided with more ribosomes and Golgi CELL STRUCTURES AND THEIR FUNCTIONS bodies. Muscle cells, on the other hand, are provided with more mitochondria to CELL SIZE produce more energy needed in muscle contraction. Bacterial: 1-10 μm Plant and animal: 10-50 μm CELL SHAPE Neuron/Nerve Cell has a cytoplasmic extensions, such as axons and dendrites, that are important in the performance of its functions. Skin Cell - has a cytoplasmic extensions, such as axons Flat cells that help cover the body from the external environment.  TYPES OF CELL PLASMID A small, circular, extrachromosomal DNA PROKARYOTIC CELL molecule found in the cytoplasm. Have a relatively simple organization. It is separate from chromosomal DNA Mostly microscopic, measuring from 1-10 μm NUCLEOID Unicellular Region where DNA is concentrated pro “before” CYTOPLASM Karyon “kernel” Do not have a membrane-bound. The whole inside region of the cell where Archaebacteria and Eubacteriia chromosomes, ribosomes, and other cellular inclusions are suspended RIBOSOME The site where proteins are synthesized or created PILUS (PILI) A short, hairlike appendage on the surface of bacteria. It helps bacteria adhere to the surface of host GLYCOCALYX/CAPSULE cells. It can also be used to transfer genetic material An outer layer that provides protection. from one bacterium to another, in which case it Important virulence factor since it protects is called sex pilus disease-causing bacteria. FLAGELLUM/FLAGELLA It helps hold on to surfaces and protects them from being engulfed by macrophages. A long, threadlike structure that facilitates Exists as a rigid capsule or a more unstructured movement in bacteria slime layer FIMBRIAE CELL WALL Bristle-like fibers that are shorter than pili. A structure that confers rigidity and shape to the It is primarily used for bacterial attachment to cell. tissue surfaces. Found outside of the plasma membrane and composed of peptidoglycan PLASMA/CELL MEMBRANE A structure that prevents the loss of water and electrolytes inside the cell. Prevents the entry of unwanted substances into the cell. Composed of phospholipid bilayer  EUKARYOTIC CELLS ❖ Fluid Mosaic Model Garth Nicolson Complex than prokaryotic cell. Jonathan Singer Measures 10-100 μm in diameter. Proposed the fluid mosaic model of the Bigger than prokaryotic cells. plasma membrane. Eukaryotic cells are those from animals, plants, It states that at normal temperature, the protists, and fungi plasma membrane behaves like a thin layer of fluid covering the surface of the cell and that individual phospholipids diffuse rapidly throughout the surface of the membrane. It is termed mosaic because it includes integral proteins that protrude above or below the lipid bilayer, peripheral proteins, cholesterol, and other molecules. CELL MEMBRANE/PLASMA MEMBRANE A thin layer that separates the cell from its external environment. The outermost covering of animal cells and functions as a selective barrier that regulates the entrance and exit of substances into out and of GLYCOCALYX cells. Selectively permeable membrane. The external coating of the cell membrane and is It provides shape and flexibility for the cell. made up of glycoproteins and polysaccharides. Functions: Two models: - provides protection ❖ Classical Model (1935) - enables cell-to-cell recognition James Daniell - contains receptor or contact sites for Hugh Davson enzymes and hormones. Proposed the classic model - allows the cell to respond to changes in Hypothesized that cell is covered by a electrical potentials. thin, flexible envelope made up of - acts as a filtration barrier phospholipid bilayer and proteins. CYTOPLASM Through the help of the early electron microscopists, it was confirmed that the region of the cell that surrounds the nucleus. phospholipid membrane has It is semifluid matrix, and it is the largest interior hydrophobic and hydrophilic ends part of the cell where organelles and cellular Sandwich inclusions are suspended.  CYTOPLASMIC ORGANELLES MITOCHONDRION The power plant of the cell. ENDOPLASMIC RETICULUM It contains enzymes that help in the chemical oxidation of food molecules and produces network of intercommunicating channels of energy on the form of ATP. membrane-enclosed sacs and tubules. A single liver cell have more mitochondria many serves as an intracellular highway through which as 2, 500 mitochondria, while skin cells will have molecules can be transported from one part of only a few hundreds the cell to another ROUGH ER (RER) Mitochondria have their own ribosomes and - Looks rough due to the presence of DNA, which means that new mitochondria arise ribosomes on its membrane surface. only when existing one divide - A cell with more RER produces a large LYSOSOMES amount of proteins to be inserted into small, spherical, membrane-bound organelles the membranes or exported to the which contains various kinds of enzymes. outside They protect a cell from invading bacteria and other pathogens breakdown damaged or worn out cell parts. They can engulf and digest targeted molecules SECRETORY GRANULES Large, dense granules with membranes. These fuse with the cell membrane to secrete substances such as enzymes, proteins, and SMOOTH ER (SER) signaling molecules out of the cell - More tubular and nongranular due to LIPID DROPLET the absence of ribosomes. Store fatty acids and sterols. - Involved in the synthesis of steroids in They take up much space and volume in gland cells, breakdown of toxic adipocytes or fat cells. substances by liver cells, and regulation They appear as black spherical bodies of varying of calcium levels in muscle cells sizes when stained CELLULAR MACROMOLECULES RIBOSOMES Not considered organelles because they are not surrounded by membranes. Each ribosomes is an assemblage of two organic GOLGI APPARATUS compounds, namely proteins and RNA. Similar to the ER, is also a system of membranes. They are the molecules that synthesize proteins. It appears as a series of flattened sacs with a Proteins that are needed by the cell itself are characteristics convex shape. produced by the free ribosomes, while proteins It is responsible for the processing, packaging, that will be inserted into the cell membrane or and sorting of secretory materials for use within exported outside of the cell are produced by the cell or for exocytosis (cell secretion) those attached to the endoplasmic reticulum. CENTROSOME Part of the cytoplasm that produces microtubules. In animal cells, it forms two small parts called centrioles.  Centrioles NUCLEUS - small cylindrical structures made of The most visible part of eukaryotic cell is the short microtubules arrange in a circle. nucleus. - To assist in cell division - studies shown that certain cells continue site where nucleic acids are synthesized. to divide even without them Serves as the site for the storage of heredity factors. CYTOSKELETON Source of ribonucleic acid (RNA), a molecule responsible for converting genetic instructions in Provides motility and strength for the cell DNA into functional substances such as proteins the collective term for the network of filaments Some cells, however, such as blood cells and and tubules that extends throughout the cell. platelets, lose their nucleus as the mature Types of Fibers 1. Nuclear Membrane Microtubules Composed of two layers which separate the - Long, slender, protein tubes. nucleus from the cytoplasm. - It is composed of linear polymers of contains ribosomes on its outer membrane. tubulin. also continuous with the endoplasmic - A network of microtubules forms the reticulum spindle apparatus that appears 2. Two Layers during cell division. Nucleoplasm - dense, protein-rich substance - These also form the cores of the cilia inside the nucleus. and flagella of the sperm cells and Nucleolus - Spherical, unbound (structures play a role in maintaining cell shape responsible for ribosomes formation) Microfilaments 3. Nuclear Pores - It supports the cell to maintain its Openings in the nuclear membrane. structure and shape, as it provides Act as selective channels between the resiliency against forces that can cytoplasm and the inside of the nucleus, alter its shapes. selectively allowing molecules that come in - Spindle fibers- and out the nucleus. o aid in the movement of The proteins that make up the nuclear pore chromosomes during cell complex are arranged radially with a large division. central hole o Important in cytoplasmic 4. Chromatin streaming or cyclosis. Made up of DNA and proteins and forms GLYCOGEN GRANULES chromosomes during cell division. Chromosomes contain the genes inherited Abundant in liver cells. by the offsprings from their parents. Play an important role in glucose metabolism Humanhave46chromosomes. BIOLOGICAL PIGMENTS Each organisms have its own specific number of chromosomes. Abundant in plant cells, particularly in Abnormalities in the chromosomes structure photosynthetic cells. or aberration in the chromosome number Found in plastids, such as the can lead to a genetic disorder or even death chloroplastids/chloroplasts, where chlorophyll pigments abound.  CELL MODIFICATIONS AND ADAPTATIONS ANIMAL TISSUE CELL MODIFICATION 1. Epithelial tissue Refers to a process in which an ordinary or Consist of sheets of cells that cover and line generic cell is transformed into a specialized cell cavities. in order to do specific task for the body. Different types of epithelial tissues cover the Contributed much to the adaptation and survival surfaces of the mouth, stomach, lungs, heart, of organisms. and blood vessels. Some have microvilli, while others are not. They also form glands that secrete substances, Microvilli- Cytoplasmic extensions that increase such as the sebaceous and salivary glands. the surface area of a cell, hence, increasing the Vary in shape (Squamous, Columnar, Cuboidal, or absorption of nutrients ciliated. CELL MODIFICATION IN ANIMALS Joined by zonulae desmosomes, and other 1. Nerve Cells junctions Mostly facilitate elongated, the Epithelial tissues can be classified according to transmission of impulses from the brain the following: to the spinal cord and different parts of a) Number of cell layers: simple or stratified the body b) Shape of cells on free surface: 2. Red Blood Cells squamous, cuboidal, or columnar Have a biconcave-disc shape and are c) Surface specialization: cilia, keratin, or highly deformable. glands 2-3 μm in diameter allows for easy Types: movement through the blood vessels. Simple squamous – heart Red blood cells and platelets lose their Simple cuboidal – kidneys nucleus when they mature. Transitional – bladder Losing the nucleus increases the surface Stratified squamous – skin area for gas exchange, enabling the Simple columnar – intestines optimal oxygenation of tissues in the Ciliated cell – respiratory tract body 2. Connective Tissue 3. Sperm Cell Tendons usually bind a muscle to a bone, while Have a tail, the flagellum, which propels ligaments connect a bone to another bone. them toward the egg for fertilization. Notice that blood is considered a supportive Have plenty of mitochondria along their tissue because its primary function is to supply middle piece, which power that the body with the nutrients and the gases that it flagellum to move them toward the egg needs. This is an example of a supportive cell function 3. Muscle Tissue CELL MODIFICATION IN PLANTS Voluntary Muscles 1. Root Hairs - Can be controlled at will by the Mostly elongated outgrowths from the organism. outer layer of root cells that help absorb - Controlled by the somatic system. water minerals. - For example: skeletal muscles attached They increase absorption and the area to bones capacity of the roots Involuntary Muscles 2. Guard Cells in Leaf’s Stoma - Move without the organism’s conscious The presence of cell-cell junctions, the control. point where two cells come together. - Controlled by the autonomic nervous Through the cell junctions, the cells are system. joined in long term associations, thus forming tissues and organs  - For examples: muscles of the digestive Kinds of MT Based on Location tube and heart a) Apical Meristems Types of Muscle tissues - Found at the tips of the shoots a) Skeletal Muscle - Made up of a very long and roots. cylindrical, multinucleated cells capable - Responsible for the increase in of quick and forceful contractions that length of roots and stems. are usually controlled voluntarily. b) Intercalary Meristems b) Visceral / Smooth Muscle - Found at the vicinity of nodes - Collections of cells that do not which occur at intervals along show cross-striations. stems. - They are the largest at their - They increase the length of midpoints and taper toward stems. their ends. c) Lateral Meristems - Their contraction process is slow - Found along the sides of some and involuntarily. roots and stems. c) Cardiac Cells - Increase the girth or diameter of - Composed of elongated, plants branched individual cells that 2. Non-meristematic or Permanent Tissues are configured parallel to each These are tissues formerly derived from the other. meristems but have already developed, - They are capable of involuntary, matured, and assumed various shapes and vigorous, and rhythmic sizes related to their specific functions. contractions. Most of these no longer undergo cell division - Intercalated discs connect adjacent cells and ensure the Structure and Function synchronicity of cardiac 1. Surface tissues serve as the outermost covering of contractions plants. 4. Nervous Tissue a) Epidermis - the outermost layer of cells of all Mostly found in the brain and in the spinal cord. young plant organs. Types b) Periderm a) Sensory Neuron - Carry information the layer of cells that replaces the obtained from the interior of the body epidermis. and the outside environment to the It gives added protection and is usually central nervous system found in mature plants b) Motor Neuron - Carry impulses from the consists of several layers of dead cells central nervous system to effector impregnated with suberin, a waxy organs commanded by these centers substance. found in barks of trees. PLANT TISSUE 1. Meristematic or Embryonic Tissues Mostly located at the tips of the roots and shoots of the plant where cells actively divide. Responsible for the production of more cells 2. Fundamental tissues are designed to give support and strength to the plant. a) Parenchyma The most abundant of all types Found in almost all major soft parts of higher plants More or less spherical in shape When they mature, they push against each other and their thin pliable cells are flattened at the points of contact These are the groups that of cells mostly active in photosynthesis, secretion, food storage, and other plant activities b) Collenchyma Composed of thick-walled cells with uneven thickness. They often occur just beneath the epidermis These cells are “stretch” in nature to allow some parts of the plant to bend and not break c) Sclerenchyma Characterized by cells with thick and tough cell walls. Impregnated with lignin. Most of them are dead at maturity and function for support They are commonly found in pears and chicos. Also known as “stone cells” 3. Vascular tissues are involved in the transport of substances inside the body of plants. a) Xylem- Conducts water and minerals upward. b) Phloem- Translocate food material to the different parts of a plant. Who is a producer? SOUNDS A person who targets audiences by catering to Major-sounding scales and chords: brighter, their interests and providing platforms that cheerier sound would suit their needs and (Magpile, 2016 Minor scales and chords: darker, sadder sounds What is an audience? CAMERA SHOTS group of spectators in a public 2016 EXTREME LONG SHOT Who are stakeholders covers a wide area, thus, framing the subject including a vast amount of its surroundings. A group of people or organization that has the often used to provide context for the scene or same interest or concern with a particular group show far transportation (Magpile, 2016 also called extreme wide shots such as a large They are the direct beneficiaries of what the crowd scene or a view of scenery as far as the media produce. They are the ones whose needs horizon. It depicts distance, thus, covering a huge are satisfied. (Magpile, 2016) area What is language? LONG SHOT pertains to the technical and symbolic Intended to show a setting within a certain ingredients or codes and conventions that media distance and information professionals may select and Does not cover great distances unlike the use in an effort to communicate ideas, previous one information and knowledge. (Media and Information Literacy TG, 2016 MEDIUM LONG SHOT - shows a group of people in interaction with each other with part of their What are media languages? surroundings in the picture codes, conventions, formats, symbols and FULL SHOT- shows the subject fully, from head to toe in narrative structures that indicate the meaning of order to show action -used for dialogue sequences, and media messages to an audience. (Media and they allow the viewer to pick up on the character's Information Literacy TG, 2016 movements and gestures. What are codes and conventions? MEDIUM SHOT- shows a subject down to his/her waist, CODES are systems of signs, which create or chest (medium close up)-commonly used for meaning interviews or newscasting because it directs the viewers CONVENTION a standard or norm that acts as a to the subject rule governing behavior (MIL TG CLOSE UP SHOT- a full-screen shot of a subject’s face TYPES OF CODE showing the finest nuances of expression 1. Technical Codes EXTREME CLOSE UP SHOT- ways in which equipment is used to tell the story a shot of a hand, eye, mouth, or any object in (camera techniques, framing, depth of fields, detail lighting and etc.) removes all possible distractions, thus focusing include sound, camera angles, types of shots on the minute details and lighting. CAMERA ANGLES Aerial Shot Overhead Shot also called Bird’s Eye Shot  long or extreme long shot of the ground from the air High-Angle Shot Camera is positioned looking down. shows people or objects from above higher than eye level makes the subject look weak or vulnerable Low-Angle Shot Camera is positioned facing upwards shows people or objects from below, lower than eye level subject looks more dominant and powerful Eye-Level Shot views a subject from the level of a person’s eye neutral, normal viewing level gives the viewer sense of equality Canted/Dutch Angle an intentional camera tilt camera is not leveled in the horizon aims to make the viewers uneasy and creates imbalance 2. Symbolic Codes - show what is beneath the surface of what we see (objects, setting, body language, clothing, color, etc.) 3. Written Codes - use of language style and textual layout (headlines, captions, speech bubbles, language style, etc. )