Bio Chapter 2 Notes PDF

Levels of Chapter 2 Organization Lesson 2.1: The Cell as an Efficient, Open System All characteristics of life come from a highly ordered structure. It star...

Levels of Chapter 2 Organization Lesson 2.1: The Cell as an Efficient, Open System All characteristics of life come from a highly ordered structure. It starts very _______________ and each new level becomes more complex. simple We know that ____________ are the basic unit of life and, as such, they organism cells facilitate life processes such as: Intake of Nutrients Exchange of Gases Movement and Growth WasteRemoval Response to Stimuli Reproduction There are two basic types of cells: ______________________________ (before nucleus) Trokaryotes is o Organisms without a cell _______________ nucleus Increase in complexity S o No membrane bound organelles o _______________ celled organisms no nucleus Single o Very small in size ______________________________ (true nucleus) Eukaryotenfaeus o Contains a _______________ organ o Has many organelles surrounded by a membrane o Larger than prokaryotes o Can be _______________ or ____________-cellular organisms single multi Eukaryotes Chemical Composition of Cell Structures tissue The major elements making up the structure of plant and animal cells are _______________, carbon hydrogen _______________, _______________ and _______________. These elements are organized oxygen nitrogen into four major organic compound groups: Lipids o _______________ – fats and oils o ______________________________ – sugars, starches, cellulose Carbohydrates cell o _______________ – muscle fibre o _______________ Acids – main component of genetic material DNA Both plant and animal cells have an internal network of fibres, called the ______________________________, made of proteins and lipids. cytoskelftforts The cytoskeleton _______________ the cell. organelle 1 Cell Organelles An organelle is a structure that performs a specific function within in a cell. Cell Structure Function A protective membrane that allows the transport of materials into Cell Membrane and out of the cell. FOUND IN PLANT CELLS ONLY Cell Wall A rigid frame that provides strength and support. A gel-like substance where organelles and nutrients are suspended. Cytoplasm The physical nature of the cytoplasm allows for easy movement of (Cytosol) molecules within the cell (called cytoplasmic streaming). Directs all cellular activities and contains the genetic material of the Nucleus cell (DNA). The nucleus is surrounded by a nuclear envelope (membrane) that has pores to allow transport of material. Site of cellular respiration in the cell. Chemical energy in sugars is Mitochondria converted to energy the cell can use. “The powerhouse of the cell.” Flat, disc-shaped sacs that receive substances from the endoplasmic Golgi Apparatus reticulum and packages them for transport out of the cell. Granules where amino acids are combined to make proteins (protein Ribosomes synthesis). May be attached to the rough endoplasmic reticulum or free-floating. A series of small, interconnected tubes that branch from the nuclear membrane. Materials can be transported through these tubes. Endoplasmic Rough ER: has ribosomes attached and is associated with protein Reticulum synthesis. Smooth ER: does not have ribosomes attached and is associated with fat and oil production. In general vacuoles are used for storage and vesicles are used to transport substances throughout the cell. Both vacuoles and vesicles Vacuoles and are bounded by a membrane and are used to store products of Vesicles secretion, nutrients, and fats. In animal cells: There are many small vacuoles that store food, cell products and excess fluids. In plant cells: There is one large central vacuole used to store water. FOUND IN PLANT CELLS ONLY Contain chlorophyll (green pigment) and is the site of Chloroplasts photosynthesis. Energy from the sun is used to convert carbon dioxide and water into sugars that can be used by the plant. FOUND IN ANIMAL CELLS ONLY. Lysosomes Membrane bound sacs that contain digestive enzymes. Lysosomes also defend against bacteria, and break down/recycle damaged cells. FOUND IN ANIMAL CELLS ONLY. Centrioles Two short rods made from microtubules thought to be involved in cell division. 2 Example 1 Label the organelles and structures in each of the cells given below. A. Cell Membrane H. Nucleus B. Cell Wall ant Only I. Nuclear Envelope C. Chloroplasts ant Only J. Pore D. Cytoplasm /Cytosol K. Rough Endoplasmic Reticulum E. Golgi Apparatus L. Ribosomes F. Lysosomes inima Only M. Smooth Endoplasmic Reticulum G. Mitochondria N. Vacuoles and Vesicles 0 Centrioes inima Only O G 3 I J G central J Vacuole C 3 4 I Lesson 2.2: The Role of the Cell Membrane in Transport A Model of the Cell Membrane equilibrium The cell membrane has a very important job of maintaining _______________________ inside of the cell. essential Movement in and out of the cell is ____________________ to survival. o ________, __________________, ons moleculesand other cells must be able to enter and leave the cell. matter energy o The cell is an ____________ system (free flow of both _____________ and _____________). open The cell membrane is a __________-______________________________ protective barrier. Everffffeable o Permeable means ____________________ can pass through it. o Impermeable means ____________________ can pass through it. nothing o So, a semi-permeable membrane is a selective filter that only lets certain substances in and out of the cell. It keeps the bad stuff out and the good stuff in. phospholipid bilayer The cell membrane consists of a ______________________________ _______________. o A phospholipid bilayer has both a hydrophobic and a hydrophilic side. Phosphates are _______________ and they love water (________________________) Lipids are _____________________ and they hate water (________________________) Bi means _________ (there are two rows of phospholipids). o Due to their nature, phospholipids naturally arrange themselves into a phospholipid bilayer. outward The hydrophilic heads love water so they point _________________________. The hydrophobic tails hate water so they point inward, toward each other. Fluid Mosaic Model The current description of the cell membrane is called the ________________________________. o The cell membrane is made up of many different parts (_______________). Mosaic fluid o The mosaic pieces are continually moving (_______________). The is flexible, not at all rigid like a wall. The cell membrane membrane also contains ____________________. proteins o Proteins are embedded in the cell membrane, floating in the phospholipid bilayer. o ____________________ channe Proteins tunnelsallowing passage of specific substances in and out of the cell. Act like ____________ Carrier Proteins o ____________________ Carrier proteins carry specific substances across the membrane both with and against the ______________________________ ________________________. concentration gradient 4  “I have no personal space” so the particles spread out. Diffusion high _________________________ is the natural movement of particles from an area of ___________ concentration to an area of ________ concentration. ow Each type of particle diffuses independently of other types of particles. The end result is a state of ______________________________, in which the particles are still equilibrium moving but they are maintaining an overall balanced, even distribution. The _______ rateof diffusion can increase by adding energy and increasing molecular movement. Diffusion is a form of ____________________ transport in which energy is NOT required. o The energy within passive the particles themselves is sufficient for the movement to occur. The particles move to balance out Diffusion in Cells difference Diffusion of water or solutes can occur across a cell membrane if there is a ____________________ between the concentration of water or solutes on either side of the membrane. This difference between the concentrations is called the concentration __________________. gradient o The concentration gradient determines the direction in which water or solutes will move. 5  The particles can't move (too big for the cell membrane) so the water moves instead. Osmosis If there is a concentration gradient across a cell membrane but the _______________________ can’t get through, the water will move across instead. molecules Water will flow to the ______________ concentrated side of the selectively permeable membrane. more o There are two ways to think about this: The water wants to make the concentration of solute the same on both dilute sides, so it will flow toward the side with more solute to ________________ it. The side with more solute has a “____________________ concentration of ower water”. The water flows to that side to obtain equilibrium. water todilute thesolin Reverse Osmosis ___________________________________ is the process of removing salt from sea water in order Desalination to make it suitable for drinking. Water is pumped through progressively smaller ____________________ that only allow filters smaller and smaller particles to pass through. The membrane removes salts and impurities from the water. o Called reverse osmosis, because the water moves from the high solute side the low solute side (the __________________ direction that osmosis would naturally flow). opposite Efficient but ____________________. expensive 6  To predict the direction of net movement for the water, we need to compare the concentrations of the solute. if et _________________________ Solution Hypertonic o Hyper means “more”, so hypertonic means “more solute”. o Hypertonic solutions have a ____________________ concentration of solute. higher Lower water concentration. o Hypertonic solutions _______________ water. gain _________________________ Solution t.name o Hypo means “less”, so hypotonic means “less solute”. o Hypotonic solutions have a ____________________ ower concentration of solute. Higher water concentration. o Hypotonic solutions _______________ water. i se _________________________ Solution Sotonic o Iso means “same”, so isotonic means “same solute”. o Isotonic solutions have _______________ concentrations of solute. equal they have reached equilibrium Substances that are soluble in water but not in lipids need some help crossing the membrane. Movement is still in response to a concentration gradient but requires help from a ____________________ facilitator. fed Diffusion ______________________________ Fa ____________________ is a form of passive transport. an open door This is where the proteins in the membrane come in: Channel proteins create channels through which small water-soluble molecules can gradient move in response to a concentration _________________________. o Channel proteins are used in ____________________ transport. passive Carrier proteins have the ability to changes shape, attach to ________________ molecules and physically move the molecule into the cell. arge original o The protein then returns to its ____________________ shape. o Carrier proteins are used in both _______________ and _______________ transport. passive active They require energy to go against the concentration gradient, but do not require energy to go with the concentration gradient. 7  Passive ____________________ Transport Requires _______ additional energy. nq.fi fea EEs Includes ____________________ and ____________________. Also includes ____________________ ____________________ on where a carrier protein or a channel protein assists a molecule that would normally not be able to cross the membrane to flow with the concentration gradient – the solute follows the concentration gradient, but the “door” is opened. Active ____________________ Transport It is sometimes necessary for molecules to move ______________ the concentration gradient. against o Special carrier proteins act as ____________________, to move substances against the concentration gradient. pumps o This is called active transport and requires energy ____________________. ad o The energy needed for active transport is called ________________________________________. yep triphosphate Endocytosis and Exocytosis Some molecules are simply too ____________ to be passed directly across the cell membrane. vestles o One last option: use ____________________ to surround the large particle and contain it. Endocytosis ________________________________________: think “enter” Esdo Enter into the cell. o Endocytosis means to bring “____________” Active membrane forms a pocket around the cell and engulfs it. o The cell ____________________ Transport ________________________________________: think “exit” Exocytosis o Exocytosis means to bring “__________” EI Efit out of the cell. fuses with o A vesicle surrounds the particle, moves to the cell membrane, ______________ ruptures it and then ____________________, releasing the contents outside the cell. Both endocytosis and exocytosis require ____________________ in the form of ATP from the mitochondrion. energy Endocytosis Exocytosis 8  Lesson 2.3: Applications of Cellular Transport in Industry and Medicine Transport of Protein Hormones _________________________ are secreted into the bloodstream and bind with receptors, Hormones causing the target cell to undergo a desired process. Example - ____________________ is a hormone that affects ____________________ levels. glucose Specialized cells in the ____________________ have channels that detect glucose in the Insulinpancreffretion bloodstream. This initiates the ____________________ of insulin into the blood. Insulin then goes to the receptor proteins of the target cells, where it ____________________ the cell to stimulates facilitated diffisvion take in glucose through ____________________ ____________________. Efficient natural systems are often used as ________________ for synthetic systems. models Knowledge of the cell membrane has prompted industrial use of synthetic membrane technologies to mimic natural functions. Synthetic Membrane Technologies ______________________ are man-made, fluid filled sacs surrounded by a phospholipid bilayer. Liposomes o Liposomes are identical to the cell membrane in human cells and can be used to deliver drugs to infected body tissue. Water trapped inside the liposomes can be used to administer water-____________________ soluble fat medications, while the phospholipid bilayer is able to store _______-soluble medications. I iiiiiiii.fi EfEEi Medication, wrapped in liposomes, can by introduced to the bloodstream and circulate providing targeted delivery of medication. infected ____________________ throughout the body, attaching to ____________________ cells, or o Advantages harm Drugs target the infected cells and do not ___________ the healthy cells. Disease can sometimes be stopped before it has a chance to take hold. discomfortto the patient. In general, there is less overall ____________________ ________ HIV and ________________ Cancer therapies rely on liposomes to deliver medication. Cancer research also uses _________________________ ____________________ to stimulate the immune defe detsf.EE system, promoting the ____________________ and _________________________ of cancer cells. on A cell’s ability to recognize molecules is important in the development of new drug therapies. 9 Membrane Proteins __________________________ Proteins Recognition o Embedded in the cell membrane, but stick ________ into the cell’s surroundings. out o They act as an _______________________ tag, allowing cells to recognize one another. identification o Cells of the human ____________________ system recognize and destroy bacteria, immune viruses, or newly arisen cancer cells. Receptor ____________________ Proteins o Bind to certain molecules and bring them into the cell through ________________________. endocytosis Lock and ________ Model __________ key Desired molecules fit into the receptor protein. The binding of the receptor protein with the desired molecule triggers the process of endocytosis. o Binding reactions on the surface of a cell can trigger many different activities within the cell. o Some viruses like human immunodeficiency virus (HIV), hepatitis, and influenza, use the binding reaction to _______________ human cells. target ____________________ Proteins and Disease Membrane o Many viruses (like HIV) attack human cells by attaching to receptor proteins. o If the virus has a “key” that fits the “lock” of the receptor protein, it is brought into the cell. blocked o If the attachment point on the receptor protein is ____________________, the virus will not be able to enter the cell. This would be like filling a key-hole with _______________. cement o Researchers trying to find treatments and cures for constantly changing viruses, such as HIV, focus on recognition or ____________________ proteins that appear to be the attachment point for the virus. receptor The hope is to develop drugs that will cover the “keyhole” to ______________ the virus from being able to attach. prevent Dialysis The purpose of ____________________ is to rid the blood of toxins, wastes and excess fluid produced dialysis by the cells of the body. Normally, healthy ____________________ would perform this task, sending wastes to be eliminated in the urine. kidneys There are two types of dialysis: ____________________ dialysis and __________________________. peritoneal hemodialysis Both are based on the principles of ____________________ and ____________________ and the diffusion operation of concentration ____________________. osmosis gradient 10 Peritoneal Dialysis In humans, cells form a membrane called the ____________________ which lines the abdominal cavity. peritoneum catheter A small plastic tube (____________________) is surgically inserted into the abdominal cavity. ____________________ dialysate fluid is pumped into the abdominal cavity. steriledialysate o The ____________________ has a composition similar to human body fluids. o The dialysate does not have any ____________________ or ____________________. toxins waste The concentration of waste materials in the blood is much ____________________ than the concentration of waste materials in the sterile dialysate fluid. higher Wastes from the body ____________________ across the membrane into the dialysate fluid. diffusseaturated As the cleansing fluid becomes ____________________ with wastes, it is removed from the body, disposed of, and replaced with fresh dialysate. The patient is able to perform peritoneal dialysis at _____________ while carrying out home most daily activities. Hemodialysis In _________________________, blood is physically ____________________ from the body, cleansed hemodialysis removed using dialysate fluid in a special machine, and then returned back to the body. Hemodialysis must be performed in a ____________________ facility because the patient is not free to move about. heath care 11 Lesson 2.4: Surface Area and Volume of Cells 5 __________ is a real problem for a cell. ____________________, _______________, and _______________ must reach all parts of the cell. Nutrients water oxygen waste products must be eliminated from the cell before they poison it. _____________ surface The rate at which the materials can enter or leave the cell is limited by the ______________ ____________ of the cell membrane. doors o The ____________________ the surface area, the more membrane exposed to the greater environment, the more materials can move into, or out of, the cell. feed As the cell grows larger, more materials are needed to ____________________ the cell and more waste products are produced which must be eliminated. __________________ volume determines how far materials must move to diffuse throughout the cell. o An increase in volume makes it more difficult for a cell to ____________________. survive Surface Area to Volume Ratios SA vs V Tell us the amount of surface area that is available per unit of volume (cm2/cm3). In order to ____________________ transportation potential, each individual cell must have largffimize the ____________________ possible surface area to volume ratio. If the surface area of the cell increased at the same rate as its volume, a large cell might be possible - but this is not the case. o As a cell gets ____________________, it’s surface area to volume ratio ____________________. bigger This limits the possible size of the cell. decreases o If a cell gets too ________, it can no longer efficiently transport materials. big Volume Calculations Surface Area Calculations =6 = =2 +2 + = 4 =4 = 3 12  Example 1 Calculate the surface area to volume ratio for each of the following cubes. Fraction Surface Area Volume SA/V Ratio Cube (cm2) (cm3) (cm2/ cm3) Height: 1 cm SA 652 53 6cm cm Width: 1 cm SA 6C 13 1am I Length: 1 cm 62 SA 6 cm cm 6 cm cm Height: 2 cm SA 652 V 53 24 cm 8cm Width: 2 cm 6 1272 23 2cm IT Length: 2 cm SA SA 24 cm V 8am 3 cm cm B Height: 3 cm SA 652 V 53 54cm 27cm Width: 3 cm SA 6 1372 Length: 3 cm SA 54 cm v 27cm 2 m Height: 4 cm SA 652 V 53 96cm 64cm Width: 4 cm SA 6 1472 Length: 4 cm SA 96 cm V 64cm 3 1.5 cm cm Sketch a graph of the surface area to volume ratio as a function of side length. SA V as a F nation ofSideLength 1 5 fÉÉÉÉ3 2 0 1 2 3 4 13 Side Length cm The graph shows that, as the side length of a cube ____________________, the surface area to increases volume ratio ____________________. This is a significant problem for a very large cell. decreases It would be harder (and take longer) for the cell to remove waste products and to deliver nutrients through the cell membrane to where they need to go. Example 2 Determine the surface area to volume ratio for the following spheres. Surface Area Volume SA/V Ratio Sphere (cm2) (cm3) (cm2/ cm3) no sa 4Er y er 1309 0.11309 SA 4 I 0.32 SA 1.13097 cm 4 0.33 1309 cm 0.11309 cm = 0.3 cm 0.11309 cm 0cm cm 18.0955 7.238 SA 4Tr2 V 4ger 2 SA 4 to 1.2 tt 1.23 8.0955 cm = 1.2 cm 7 238 cm SA 18.0955 cm 7.238 cm 2.5 cm cm SA 4Tr2 V 43 r 113.097 113.097 2 SA 4 I 3.0 I 3.03 113.097 cm = 3.0 cm g 113.097 cm SA 113.097 cm 113.097 cm 1 0 cm cm 14 Maximizing Potential maximize their surface area without increasing Cells have developed into shapes that ____________________ their ____________________ volume all that much. Your small intestine has small finger like projections called ____________. nutrie These villi increase the surface area and maximize ____________________ absorption. root The cells that line the roots of plants have microscopic projections called __________ hairs __________. Root hairs increase the amount of surface area available and maximize the nutrients water and ____________________. intake of ________________ Although cells can adopt special shapes, sooner or later they reach a size where their surface inadequate area is __________________________ to support the volume within. multicellular In order to grow any larger, the organism must become _________________________. divides o The cell __________________. Multicellular organisms need transportation systems (like our ______________________ system) to increase the efficiency of material transportation. circulatory ascellsslayers 125cells one giant cell iii cells me SA 652 SA 66572 Tell SA 150 SA 66 125 ga 6 750 55 V 53 53 13 125 125 125 SAN SAN 15 1501125 750 125 12 6