An Outline of the Cell Theory

Chapter 2 IB biological science 2. 1 kiosk Theory 2. 1. 1 Outline the cubicle possible action (2). all(prenominal)(prenominal) in all beings be composed of one and only(prenominal)(a) or to a greater extent than mobile phones kiosks be the smallest units of life wholly cadres precipitate fling off from preexisting mobile phonephones TOK cadre possibleness renews the prep argonr ideas of spontaneous ingredientration or abiogenesis in which inanimate involvement assembles itself into living homunculuss Exception muscle carrels- much than 1 nucleus, truly long (fungal mobile phones) hyphae roots- non a single unit protoctista- non specialized to single function sub prison mobile phonephoneular things handle organelles 2. 1. Discuss the evidence for the electric stall theory (3). Robert Hooke first described mobile phones in 1665 maculation observing cork with a microscope he built. Coined the term jail cellular phoneular telephoneAntoine van Leeuwenhoek discove flushed the 1st living cells and referred to them as animalcules. microscope In 1838, botanist Mathias Schleiden stated that embeds atomic number 18 make of independent sepa rank being called cells. Later, Theoder Schwann make a similar statement closely animals. The 2nd principle continues to gain attendant beca wasting disease we put on non been satis operatory to get word some(prenominal) living entity that is non do of at least one cell. Louis Pasteur in the 1860s per exploited experiments to support the dwell principle. After sterilizing yellowish broth by boiling, Pasteur showed that living beingnesss would not spontaneously reappear. biogenesis Only after exposure to preexisting cells was life fitting to re-establish itself in the chicken broth. eukaryotes- mitosis procaryotes- binary atomic fission thus all cells have a common ancestor- original ancestral relieve oneself 2. 1. 3 resign that unicellular beings carry knocked emerge (p) all the functions of life (1). Functions include Metabolism- chemical substance reactions that pass deep down an being Growth- whitethorn be limited but is al behaviors sp be in bluntly way Re exertion- communic up to(p) molecules that toilet be passed to offsp multitude Response- to surroundings is imperative to survival Homeostasis- main(prenominal)tain a constant home(a) environs ex temp Nutrition- generate a ancestry of compounds with umpteen chemical bonds which groundwork be broken to provide the organism with the NRG and the nutrients necessity to suffer life CHNOPS 2. 1. 4 contrast the relative step to the fores of molecules, cell tissue layer thickness, viruses, bacteria, organelles and cells, victimization the appropriate SI unit (3). Cells- one hundred micrometer calipers ( represent) Organelles- &lt 10 micrometers Bacteria- 1 micrometer Viruses- 100 nanometersMembranes- 10 nanometers thick Molecules- 1 nanometer Animal cell- 10 micrometers cm = 10-2 m mm = 10-3 m um = 10-6 m nm = 10-9 m A = 10-10 m 2. 1. 5 Calculate the linear overstatement of drawings and the actual coat of exemplars in interprets of cognise magnification (2). Magnification = size of it of image secernated by the size of specimen Magnification = measured length / outdo bar level Actual size = measured length / magnification 2. 1. rationalize the importance of the find playing field to mickle ratio as a factor limiting cell size (3). In the cell, the rate of heat and waste turnout and rate of resource consumption ar functions that depend of its volume. Most of the chemical reactions fade in the interior of the cell and its size affects the rate of these reactions.The surface of the cell, the tissue layer, controls what materials prompt in and out of the cell. Cells with more surface are per unit volume are able to mint materials in and out of the cell, for apiece unit volume of the cell. As the immenseness of the object ontogenys, the surface study as well as increases but at a overmuch slower rate than the volume. This way that a large cell has less surface knowledge domain to bring in required materials and to rid the cell of waste than a small cell. Because of this, cells are limited to the size they bay window attain and still be able to carry out the functions of life. giant animals have more cells not large ones. A large surface area to volume ratio means the cell can act more efficiently for every unit of volume that requires nutrients or produces waste, there is more tissue layer to serve it. But this is not always an receipts- cell can lose heat quickly.As organisms grow, cells catchment basin. 2 small cells are more efficient than one. Alveoli in lungs maximize surface for gas transposition. 2. 1. 7 republic that multicellular organisms show emergent properties (1). Different things come together to make exercise Cells-tissues-organs-etc. world power to reproduce themselves. Al lows possibility of growth and for alternate of damaged or dead cells. 2. 1. 8 radiation patternulate that cells in multicellular organisms part to carry out specialized functions by expressing some of their genes but not others (3). stolon out as single cell that reproduces at a rapid rate therefore the resulting cells go finished a differentiation (different cells- different functions- to run an organism) wait on to produce all required cell founts that are necessary for organism. Every cell in a multicellular organism constitutes all the genes of that organism. However, the genes that are activated substitute from cell to cell. Differentiation- when we break something complex into its voice pieces, they distributively appear to be childlike. Combined, they can perform a whole sassy function.Cells within a multi cellular organism specialize their function. Examples muscles cells, cardiac cells This differentiation demonstrate is the result of the expression of certa in specialised genes but not others Genes allow for the production of all different cells in the organism distinguishly cell ceases all the genic info for the production of the complete organism Each cell becomes a peculiar(prenominal) part of cell dependent of which desoxyribonucleic acid segment becomes active 2. 1. 9 State that rootage cells retain the capacity to divide and have the ability to differentiate on different pathways (1). Retain ability to divide and differentiate into various cell types embryologic basis cells retain the ability to form any type of cell in an organism and can even form a complete organism When shank cells divide to form a specific type of tissue, they too produce some cells that re stead as hold cells. This allows for the insistent production of a finicky type of tissue.Pluripotent- give rise to any type of cell Treating diseases? 2. 1. 10 Outline one therapeutic use of nucleotide cells (2). flip-flop differentiated cells lost c allable to wound Therapeutic cloning- implanted under expression cells replace lost cells Tissue- specific stem cells- these cells rest in certain tissue types and can only produce new cells of that particular tissue For example, stem cells have been introduced to humanity to replace the damaged ram amount of money of some leukemia longanimous ofs Bone burden transplants are one of the many therapeutic uses of stem cells. Stem cells found in the rise marrow give rise to the red blood cells, white blood cells and scale leaflets in the body. These stem cells can be utilize in bring up marrow transplants to delicacy people who have certain types of crab louse.When a patient has cancer and is given gamey doses of chemotherapy, the chemotherapy kills the cancer cells but also the median(prenominal) cells in the bone marrow. This means that the patient cannot produce blood cells. So in the begetning the patient is treated with chemotherapy, he or she can undergo a bone m arrow harvest in which stem cells are re go ond from the bone marrow by development a needle which is inserted into the pelvis (hip bone). Alternatively, if stem cells cannot be apply from the patient indeed(prenominal) they can be harvested from a matching donor.After the chemotherapy treatment the patient will have a bone marrow transplant in which the stem cells are transplanted back into the patient th around and through with(predicate) a drip, usually via a mineral vein in the chest or the arm. These transplanted stem cells will wherefore find their way back to the bone marrow and approach to produce healthy blood cells in the patient. Therefore the therapeutic use of stem cells in bone marrow transplants is very important as it allows some patients with cancer to undergo broad(prenominal) chemotherapy treatment.Without this therapeutic use of stem cells, patients would only be able to take low doses of chemotherapy which could lower their chances of curing the diseas e. Ethical issues- embryonic stem cells come from embryos obtained from labs doing IVF. involves death of embryo. 2. 2 Prokaryotic Cells 2. 2. 1 Draw and set a draw of the ultrastructure of Escherichia coli (E. coli) as an example of a prokaryote (1). Plasmid is government note thing not on plot. Refer to book. Size of cell 1-2 um Absence of tissue layer bound organelles procaryote examples (look at notes for pictures) straight rod- Escherichia Club wrought rod- corynebacterium Spore forming rods- bacillus Coccus Staphylococcus 2. 2. 2 Annotate the diagram with the functions of each named structure. Cell groin Protects the cell from the outside environment and maintains the tempt of the cell. It also prevents the cell from bursting if internal pressure rises. ?? Plasma tissue layer Semi-permeable membrane that controls the substances moving into and out of the cell. It contains integral and peripheral device proteins.Substances pass through by either active or nonoperat ional carry-over.?? cytoplasm Contains many enzymes employ to turn chemical reactions of metabolism and it also contains the deoxyribonucleic acid in a kingdom called the nucleoid. Ribosomes are also found in the cytoplasm. ?? Pili Help bacteria adhere to each other for the exchange of contagious material. Involved in sell of deoxyribonucleic acid in a process called conjugation (direct contact in the midst of bacterial cells in which blood plasma desoxyribonucleic acid is transferred mingled with a donor and a receiving system cell) Flagella (singular flagellum) Made of a protein called flagellin.Helps bacteria move around (mobility) Ribosomes They are the site of protein price reduction. Contributes to protein synthetic thinking by translating messenger ribonucleic acid.?? free in cytoplasm (70s) Nucleoid Region containing deoxyribonucleic acid gnarly with cell control and sound reflection Plasmid- small, circular DNA not connected to main chromosome parallel inde pendently of chromosomal DNA not required by cell under normal conditions but it may help the cell adapt to crotchety circumstances normal to find at least one anti-biotic resistance gene within a plasmid oozing capsule- sticky layer outside of cell wall, sticks cells together . 2. 3 Identify structures from 2. 2. 1 in electron micrographs of liver-colored cells (2). 2. 2. 4 State that prokaryotic cells divide by binary fission (1). Binary fission- simple member process in which DNA is copied and 2 daughter chromosomes become machine-accessible to different components on plasma membrane and cell divides into 2 genetically very(a) daughter cells. Process elongation of cell 2. 3 Eukaryotic Cells 2. 3.1 Draw and label a diagram of the ultrastructure of a liver cell as an example of an animal cell (1). . 3. 2 Annotate the diagram with the functions of each named structure. Ribosomes Found either floating free in the cytoplasm or attached to the surface of the rough endoplasmic s econd stomach and in mitochondria and chloroplast. Ribosomes are the site of protein synthesis as they translate messenger RNA to produce proteins. bowelless endoplasmic reticulum mint interchange proteins to alter their function and/or destination. Synthesizes proteins to be excreted from the cell. Lysosome catalyze the breakdown of proteins, nucleic acids, lipids and carbs, blende with old or damaged organelles so recycling can occur, breakdown of materials that are brought in by phagocytosis Golgi apparatus Receives proteins from the rough endoplasmic reticulum and may further modify them. It also packages proteins before the protein is sent to its final destination which may be intracellular or extracellular. Mitochondrion Is trus bothrthy for aerobic respiration. Converts chemical energy into adenosine triphosphate using oxygen. Nucleus Contains the chromosomes and therefore the patrimonial material.It is responsible for controlling the cell. Extra shine ER- production of membrane phospholipids can cellular lipids, production of sex hormones, detoxification of drugs in liver, memory board of calcium ions needed for muscle contractions, rapture of lipid based compound, to aid in liver in releasing glucose into blood stream when needed Centrosome- a pair of centrioles at right angles winding in assemblage microtubules which are important in providing structure and allowing accomplishment and cell division Vacuole- store organelle store potential sustenance to provide nutrition, metabolic wastes and toxins to be expelled, and ater enables cells to have a spiriteder surface area to volume ratios even at bigger sizes in plants, uptake of h2o provides inflexibility 2. 3. 3 Identify structures from 2. 3. 1 in electron micrographs of liver cells (2). 2. 3. 4 equal prokaryotic and eukaryotic cells (3). Prokaryote Eukaryote DNA in a ring form without proteinDNA with proteins as chromosomes/chromatin granule granule DNA free in the cytoplasm- no n ucleusDNA envelop within a atomic windbag No mitochondriamitochondria 70S ribosomes80S ribosomesNo internal compartmentalization to form organellesinternal compartmentalization present to form many types of organelles Size less than 10 micrometersSize more than 10 micrometers also unicellular vs. multicellular no membrane bound organelles vs. membrane bound organelles binary fission vs. mitosis agamic riposte vs. asexual and sexual reproduction similarities both cells have some dissever of outside boundary that always involves a plasma membrane, both carry out all functions of life, DNA is present in both . 3. 5 State 3 differences between plant and animal cells (1). go down Animal Outer cell wall with a plasma membrane vertical privilegedOnly a plasma membrane Chloroplasts No chloroplasts Large centrally located vacuolesNo vacuoles/ or small ones Store carbs as starchStore carbs as glycogen Do not contain centrioles within a centrosome areaContain centrioles within a centro some area Fixed, a lot angular, counterfeit because of a rigid cell wallCell is flexible and more likely to be a rounded shape . 3. 6 Outline 2 components of extracellular components (3).The plant cell wall gives the cell a lot of strength and prevents it from bursting under elevated pressure as it is made up of cellulose arranged in groups called microfibrils. It gives the cell its shape, prevents excessive urine up take by osmosis and is the reason why the whole plant can hold itself up against gravity. Prevents opening of pathogens. Allows turgor pressure/ high pressure to suffer inside the cell. The animal cell contains glycoproteins in their extracellular matrix (ECM) which are involved in the support, driving force and adhesion of the cell. Cell to cell interaction, strengthens plasma membrane, allows attachment between adjacent cells, directs stem cells to differentiate 2. 4. 1 Draw and label a diagram to show the structure of membranes (1). 2. 4. 2 Explain how the hy drophilic and hydrophobic properties of phospholipids help to maintain the structure of cell membranes (3). One area of membrane is pee soluble and frigid and is hydrophilic The other area isnt water soluble and is non polar- hydrophobicThese hydrophobic and hydrophilic portions cause phospholipids to always organize as a bilayer if there is water present and there is a large number of phospholipid molecules Membrane is flexible since sebaceous acid tail do not strongly attract one another(prenominal) What maintains the overall structure of membrane is the mark water has to form hydrogen bonds In hydrophobic region (fatty acid tails) in animal cells these are cholesterol molecules- look into membrane fluidity (changes temp) Proteins are embed in fluid matrix of phospholipid bilayer (mosaic effect) inbuilt proteins have both hydrophobic and hydrophilic regions in the same protein Hydrophobic region (mid section of phospholipid membrane) holds protein in place hydrophilic re gion is exposed to water solutions on either side of membrane peripheral proteins do not protrude into the midst hydrophobic region but remain bound to the surface of the membrane 2.4. 3 List the functions of membrane proteins (1). Hormone covering sites- have specific shapes that fit shape of specific hormone Enzymatic action- catalyze chemical reactions Cell adhesion- proteins hook together to form connections Cell to cell communication- provide identification Channels for passive delight- high to low stringency Pumps for active transferral- proteins skirt a substance from one side of membrane to another by changing shape adenosine triphosphate 2. 4. 4 doctor osmosis and public exposure (1). Diffusion is the passive cause of particles from a region of high concentration to a region of low concentration.Osmosis is the passive movement of water molecules, crossways a partially permeable membrane, from a region of lower solute concentration to a region of higher solute con centration (hypo-osmotic solution to hyperosmotic solution). Facilitated diffusion- involves a membrane with specific carrier proteins that are capable of combining with the substance to and its movement 2. 4. 5 Explain passive transport across membranes by simple diffusion and facilitated diffusion (3). Simple diffusion- substances other than water move between phospholipids molecules or through proteins which possess channels Facilitated diffusion- nonchannel protein carriers change shape to allow movement of substances other than water. No NRG.Polar molecules need help. Substances that move passively across membrane are influenced by size and shape Small substances and nonpolar move with ease large, polar, or both do not Channel proteins- create a hydrophilic pore in membrane through which small changed particles (ions) can spread out into cell acquit proteins- help move substances (glucose) into cell. Substrate binds to protein which carries molecules across membrane and relea ses it inside cell 2. 4. 6 Explain the role of protein pumps and adenosine triphosphate in active transport across membranes (3). Active transport involves the movement of substances through the membrane using NRG from ATP.The advantage of active transport is that substances can be moved against the gradient, meaning from low to high concentration This is possible because the cell membrane has protein pumps embedded it which are used in active transport to move substances using ATP Each protein pump only transports certain substances so the cell can control what comes in and goes out Transport or carrier proteins Ex Na +/ K + pump. Sodium moved out of cell, potassium moved in (important for organisation cells) 2. 4. 7 Explain how vesicles are used to transport materials within a cell between the rough ER, Golgi apparatus, and plasma membrane (3). Materials are transmitted between rough ER, Golgi app, and plasma membrane Nucleus contains chromosomes that contain genes for coding pro teins.RNA passes from nucleus to cytoplasm Rough ER contains ribosomes which make proteins intended for exporting Protein goes into lumen of Golgi app for processing before it leaves through the cell surface membrane by exocytosis 2. 4. 8 delimit how the fluidity of the membrane allows it to change shape, break and reform during endocytosis and exocytosis (2). The phospholipids in the cell membrane are not solid but are in a fluid state allowing the membrane to change its shape and also vesicles to fuse with it. This means substances can enter the cell via endocytosis and exit the cell via exocytosis. The membrane then returns to its original state. In exocytosis the vesicles fuse with the membrane expelling their contentedness outside the cell.The membrane then goes back to its original state. Endocytosis is a similar process which involves the pulling of the plasma membrane inward so that a vesicle is pinched off it and then this vesicle can carry its content anywhere in the ce ll. Cell takes up substance by surrounding it with membrane, ATP 2 types pinocytosis (substance is liquid) phagocytosis (substance is solid) endocytosis and exocytosis- active transport that requires ATP common in unicellular organisms abstract of processes ATP requiredConcentration gradient DiffusionNoDown (high to low) Facilitated diffusionNoDown OsmosisNoDown Active transport with carrier proteinsYesAgainst is possible EndocytosisYesAgainst is possible 2. 5 Cell Division 2. 5. Outline the stages in the cell cycle, including inter pattern (G1, S, G2), mitosis, and cytokinesis (2). The first stage of cell division is interphase which is divided up into 3 phases G1, S and G2. The cell cycle starts with G1 (Gap phase 1) during which the cell grows larger. This is followed by phase S (synthesis) during which the DNA is replicated. Finally, G2 (gap phase 2) is the second growth phase in which organelles increase in number, cell grows and preps for mitosis, DNA begins to condense form chromatin to chromosomes and microtubules begin to form. ? The fourth stage is mitosis, which is divided into prophase, metaphase, anaphase and telophase.During mitosis the stiletto heel fibers attach to the chromosomes and pull child chromatids apart, providing the same genetic material to each of these locations. This stage separates the twain daughter genomes. Finally, cytokinesis is the last stage during which the cytoplasm divides to create two daughter cells. In animal cells the cell is pinched in two to form a cleavage furrow firearm plant cells form a plate between the dividing cells. 2. 5. 2 State that tumors (cancer) are the result of uncontrolled cell division and that these can occur in any organ or tissue (1). Proto-oncogenes are genes that produce proteins, which stimulate growth (cell division). If renewal occurs, a tumor will form. Mutations radiation, viruses, chemicals that are carcinogenic, EM radiation 2. 5.3 States that interphase is an active layover in the life of a cell when many metabolic reactions occur, including protein synthesis, DNA replication, and an increase in the of mitochondria and/or chloroplasts (1). 2. 5. 4 Describe the events that occur in the 4 phases of mitosis (2). During prophase, chromatin becomes chromosomes, nuclear gasbag disintegrates, the spindle microtubules begin to form, centrosomes move toward opposite terminuss of cell due to lengthening microtubules. Each chromosome consists of 2 resembling infant chromatids held together by a kinetochore. During metaphase, the chromatids move to the equator and the spindle microtubules from each pole attach to each centromere on opposite sides. During anaphase, the spindle microtubules pull the sister chromatids apart splitting the centromeres. This splits the sister chromatids into chromosomes. Each identical chromosome is pulled to opposite poles. Chromatids of each duplicated chromosome separate and become unduplicated chromosomeDuring telophase, the spind le microtubules break down and the chromosomes uncoil and so are no longer individually visible. Also the nuclear membrane reforms. Chromosomes become chromatin (shapeless). Centrioles replicate in animal cells. The cell then divides by cytokinesis to form two daughter cells with identical genetic nuclei. 2. 5. Explain how mitosis produces 2 identical nuclei (3). During prophase, the chromosomes become visible. The nuclear envelope disintegrates and the spindle microtubules grow and extend from each pole to the equator. At metaphase the chromatids move to the equator. The sister chromatids are two DNA molecules organise by DNA replication and are therefore identical.These sister chromatids are then separated in anaphase as the spindle microtubules attaches to centromere and pulls the sister chromatids to opposite poles. As the sister chromatids separate they are called chromosomes. This means that each pole has the same chromosomes (same genetic material). Finally the microtubules break down, the chromosomes uncoil and the nuclear membrane reforms. The cell then divides into two daughter cells with genetically identical nuclei. 4 chromosomes in parent cell = 4 chromosomes in each daughter cell duplicated chromosome with 2 strands connected by centromere and chromosome is 1 strand 2. 5. 6 State that growth, embryonic development, tissue repair, and asexual reproduction involve mitosis (1). Growth- production of similar cells embryonal development- allows zygote to grow into multicellular organism Tissue repair- wounds need identical heterotaxy cells Asexual reproduction- allows for a rapid and meaning(a) increase in number of individuals