Biology Exam 2

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Chapters 4,5,6,7,8
Courtney Judd
Flashcards by Courtney Judd, updated more than 1 year ago
Courtney Judd
Created by Courtney Judd over 8 years ago
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Question Answer
What is the cell membrane? The cellular envelope that holds all cells together.
What is the cell membrane composed of? -Phospholipids, fats, proteins, and some carbohydrates. -Has pores; Permeable
What follows the fluid mosaic model? The cell membrane
What is the fluid mosaic model? -Describes the structure of the cell membrane. -A flexible layer made of lipids is sprinkled with large protein molecules that act as channels through which other molecules enter and leave the cell.
What is the Cell Wall? Provides structural support in plants
What is the cell wall composed of? Overlapping layers of cellulose fibers.
What is pectin? -A polysaccharide - Can act as a cellular glue to hold cells together by bonding the cell walls of adjacent cells.
When can the secondary cell walls be formed? -Older cells may develop a secondary wall. -Incorporates other compounds such as lignin.
What is the cytoplasm? The internal cellular fluids and all of the organelles except for the nucleus.
What is cyclosis? Internal currents in the cytoplasm that can hasten diffusion.
What are organelles? -The internal cellular inclusions which are packaged in one or two membranes. -Have distinctive features. -Carry on specific biochemical functions.
What is the nucleus? -The control center of the cell -Storehouse of DNA -Responsible for direction of the cell metabolism and cellular production.
What does the nucleus consist of? -Bi-layered nuclear membrane -Large pores -Chromatin
What is chromatin? -Chromosomes. -Consists of DNA and proteins.
Why is DNA stored in the nucleus? So it is safe and protected.
What is the nucleolus? Small dense areas within the nucleus which are the site of ribosome RNA synthesis.
What is RNA? Gives instructions for making protein.
What stains much darker than the nucleus? The nucleolus.
What is the Endoplasmic Reticulum (ER)? -A complex series of membranes found in the cytoplasm. -Continuous with the nuclear membrane -Receive ribosomes from the nucleus -Act as internal means of communication
What is the difference between smooth and rough ER? -Rough ER has ribosomes -Smooth ER lacks ribosomes
What are the responsibilities of smooth ER? -Lipid & Steroid Synthesis -Detoxification of Poisons (ex. alcohol) -Carb Transformations (ex. glucose to glycogen) -Storage of Calcium
What is the responsibility of rough ER? It is the site of protein synthesis.
What are ribosomes? -A type of RNA -Produces protein
Where does protein go when it escapes the pore of the nuclear membrane? The Endoplasmic Reticulum.
What is the Golgi Apparatus? -Double walled membrane that packages the proteins produced by the rough ER. -Provide a means for removing products from the cell by exocytosis. -Contribute building materials to the cell membrane and synthesize cellulose.
What is the Golgi Apparatus composed of? A complex series of membrane bound vesicles.
What are vesicles? -Flattened sacks -Small bundles of packaged proteins and enzymes produced by the Golgi Apparatus -They are moved to the cell membrane and dumped outside to the cell as needed.
What does the Golgi Apparatus package? Secretions and hormones.
What are lysosomes? -Bags of digestive enzymes -Phagocytosis -Single membrane bound structures -Aid developmental changes -Contain hydrolytic enzymes used to breakdown ingested products (foods, bacteria and other cells) and for self destruction of damaged cells.
What is the mitochondrion? -Energy transformation organelle. -Site of energy production (glucose to ATP) in the cell. -Contain an internal series of folded membranes called cristae. -Have their own DNA -Can reproduce themselves at will, independently.
What are plastids? Membrane bound structures that contain pigments.
What are the characteristics of chloroplasts? -Plastids -Contain chlorophyll in membrane stacks called grana. -Responsible for photosynthesis within the cells of the plants. -Have their own DNA -Can reproduce themselves at will, independently.
What are vacuoles? -Large membrane bound fluid filled chambers within the cell. -Act as reservoirs of cell products (starch, sugar, pigment) and water. -Important storage areas for water used for osmotic properties of cells. -May also be depositories for cell waste and toxic cell byproducts.
What are peroxisomes? Things that contain hydrogen peroxide.
What is the process of sunburn? 1. Excessive UV light kills living skin cells 2. Dead cells auto-destruct due to lysosome action 3. Results in inflammation because dead cells trigger attack by white blood cells 4. Darker pigmentation
What are contractile vacuoles? Expels water from the cell.
Why are there toxic cell byproducts? Some cells produce poisons like cyanide to protect themselves against animals. Ex. cherry tree, poison ivy.
What are the parts of the cytoskeleton? The microtubules and microfilaments
What are Microtubules? Fine hollow tubes which make up a soda-straw like cytoskeleton for the support and shape of the cell.
What are microtubules made of? Protein
What are microfilaments? -Protein strands which effect intracellular movements like cytoplasmic streaming (cyclosis) and movement of the chromosomes. -"Muscle of the cell" - contractile proteins -Hair-like -Move and change shape
What are cilia? -Short hair-like projections from the cell membrane -Move in wave-like fashion, front to back.
What are flagella? -Long whip-like projections. -Help cells to propel and move through water
What are basal bodies? -Small cellular inclusions which anchor flagella and cilia -Similar in structure to centrioles.
What do flagella and cilia have in common? -Both organelles for motion -Consist of a central pair of microtubules surrounded by nine pairs of microtubules.
What are centrioles? Responsible for the movement of the chromosomes during cell division.
What are other cytoplasmic inclusions? -Granules -Crystals (ex. Pyrenoids -starch crystals or Guanine crystals found in fish scales) -Globules of pure substances (fat)
How does a light microscope work? A beam of light is concentrated, passed through a thin slice of tissues or cells and then the converging light image is magnified through a series of lenses. -Microscope used in lab.
How does a Transmission Electron Microscope work? A beam of electrons is focused with a series of magnets through a very thin section of tissue which has been impregnated with metal. The resulting image is much like an X-ray of this section. Much high resolution and magnification can be attained with the electron beam.
How does the Scanning Electron Microscope work? Coats the entire surface of cells and organisms with a thin metal coating and then bounces electrons off the tissue to create a photographic image much like using sunlight for taking a photograph.
How are phospholipids arranged? In two layers forming a matrix or bi-lipid sandwich: -Polar "head" end oriented to the outside of the membrane; hydrophilic -Non-polar "tails" are oriented to the inside; hydrophobic
What are phospholipids? -Permit the passage of lipids through the membrane, weak polar molecules (H20, CO3) and some small ions. -Can be added or removed as needed by cell. -Motion of individual molecules is limited.
How do phospholipids orient themselves on water?
What are Transport Proteins? Proteins which pass through both layers of the bi-lipid sandwich and protrude on either side. -Hydrophobic, but ends are polar. -Responsible for transport in facilitated diffusion and active transport.
What are Channel proteins? Allow charged ions like Sodium, Potassium, and Chlorine into cell.
What are carrier proteins? If a molecule wants to come in, the permease enzymes will open and change shape to accept the molecule. Ex. How glucose gets into cell.
What are receptor proteins? Receive signals and trigger reactions within cell based on the signals, like chemical reactions. Ex. testosterone triggers male hormones.
Other than receiving signals, what are the 4 functions of receptor proteins? 1) Sites for hormone interactions 2) receptor sites for communication 3) Some carrier molecules 4) Perform some enzymatic reactions
What are Recognition Proteins? Identify cells based on proteins attached to cell membrane. Self=yours Non-self=Any other foreign proteins.
What are glycocalyx and what are they responsible for? When recognition proteins are bonded to proteins or lipids, they are collectively called glycocalyx's They are responsible for proper embryological development and immune responses as well as cellular recognition.
Many kinds of cancers that spread lack what? Glycocalyx's and cellular recognition codes.
What is cholesterol? -Restrains the lateral movement of phospholipids but allows the fluid nature of the membrane to persist. -At colder temperatures, the cholesterol keeps the membranes from solidifying.
What is glycophorin? The protein responsible for recognition of the different human blood groups (A, B, AB, or O).
How will solubility affect the permeability of a membrane? Substances more soluble in lipids will more readily pass through a membrane.
Order these substances in order of decreasing solubility: Ethyl alcohol, glycerol, ethyl ether. Ethyl alcohol Ethyl Ether Glycerol
How does molecular size affect the permeability of a membrane? Small molecules pass through more readily than larger molecules.
List these molecules in order of increasing size and decreasing ability to cross a membrane: Glycerol, urea, sucrose, glucose Urea Glycerol Glucose Sucrose
How does the charge of the molecule affect the permeability of a membrane? -Plasma membranes are more permeable to uncharged molecules than to charged molecules. -The stronger the charge, the more difficult it is for a molecule to cross a membrane, without assistance (transport proteins).
What is the process of poison ivy? 1) Contact 2) Has Arushinol in it 3) Skin changes membrane recognition codes for skin cells 4) Immune system attacks and destroys skin cells resulting in irritation and itchiness.
How do auto-immune diseases work? Recognition codes change and cells may be attacked by the immune system Ex. Type 1 Diabetes, Multiple Sclerosis, etc.
What is the process of Type 1 Diabetes? 1)Viral infection 2) Membrane changes code of Beta cells in pancreas 3) Immune system attacks beta cells + kills them 4) No insulin production = Diabetes Type 1
What does a rattlesnake do to cell membranes? The venom has an enzyme called phospholipase that breaks down phospholipids, so the tissue starts to dissolve.
What's the difference between benign and metastatic malignant tumors? Metastatic malignant spread to other parts of the body while benign do not.
What is diffusion? -The movement of molecules of a particular substance from areas of higher concentration to lower concentration. -Physical process
How can you increase the rate of diffusion? By increasing the rate of movement of the molecules.
What is the difference between active and passive diffusion? Active requires energy (ATP) and passive does not.
What is dialysis? The movement of small molecules or ions across a membrane. In the body, this is when blood is dialyzed by the kidneys to remove salts and urea.
What is urea? Nitrogen waste produced by liver and removed by the kidneys.
What is osmosis? Diffusion of water through a semi-permeable membrane from an area of greater concentration (lower osmotic pressure) to an area of lower concentration (higher osmotic pressure).
What is osmotic pressure? -A measure of the tendency of water to move in a solution. -The more solute in a solution, the greater the osmotic pressure. -The amount of pressure that must be exerted to keep it equilibrium when the two solutions are separated by a membrane.
What are the two relative osmotic conditions? Hypertonic and Hypotonic
What is hypertonic? A solution which has a higher concentration of osmotically active dissolved particles on one side of the membrane than the other, and thus a higher osmotic pressure.
What is hypotonic? A solution which has a lower concentration of osmotically active dissolved particles on one side of the membrane than the other, and thus a lower osmotic pressure.
What is isotonic? A solution which which have equal concentrations of osmotically active particles on either side of a membrane.
What is facilitated diffusion? Occurs when a substance that is unable to move across a membrane on its own because it is too large is moved across a membrane by its carrier molecule. Ex. Glucose>Blood>Insulin>Facilitated Diffusion in Cells.
What is active transport? -Movement of a substance across a membrane against the concentration gradient. -Requires carrier molecule and extra energy Ex. water leaking in boat, using bucket to put water back in ocean.
What is endocytosis? The process of allowing chemical or foreign bodies which are too large to pass through into the cell membrane.
What are the two subsets of endocytosis? Phagocytosis and pinocytosis
What is phagocytosis? Cell eating ex. White blood cells
What is pinocytosis? Cell drinking
What is exocytosis? The process of discharging wastes or cell products which are too large to diffuse across a membrane. Ex. hormones, proteins, waste.
How are cell membranes like the blood brain barrier? Both are selectively permeable, in that they allow certain substance to enter or leave a cell.
How does water and some other small molecules enter cells? By squeezing the molecules of phospholipids.
What is the concentration gradient? The difference in concentration of the solute when comparing 2 solutions.
What is osmotically active? Anything dissolved in water Ex. sugar, salt, etc.
What swells? Hypertonic, Hypotonic, Isotonic Hypertonic
What shrinks? Hypertonic, Hypotonic, Isotonic Hypotonic
What neither swells nor shrinks? Hypertonic, Hypotonic, Isotonic Isotonic
Which type of diabetes lacks insulin? Type 1 - Juvenile Diabetes
Which type of diabetes lacks insulin receptors? Type 2 - Adult Onset
How do sharks keep from dehydrating? They have holes that allow salt water to bathe their digestive organs.
What are "unwashed" oysters? Oyster comes from salt water High concentration of salt "wash" Soaks in fresh water Swells because it is hypertonic to water
What are restricted by the blood brain barrier? Opiates, barbiturates, and other pharmaceuticals which are given to control mind, and mental imbalances.
Why are sleeping pills and alcohol deadly? Alcohol broadens the permeability of the barrier so the effects of both are greater making it deadly.
What is entropy? The loss of orderliness and high energy level to an increase in randomness and low energy level.
What is the first law of thermodynamics? Matter and energy are interchangeable ex. energy can be stored as matter and then converted to energy.
What is the second law of thermodynamics? No transformation of energy is complete; some energy is lost in the process. This creates a steady decrease in the energy available to do work.
What is ATP? -The energy currency of life -Energy is stored in the form of chemical bonds between phosphate molecules (like batteries) -As these bonds are broken, the energy is released for work.
What does ATP stand for? Adenosine Tri-Phosphate
What does ADP stand for? Adenosine Diphosphate
What does Pi stand for? inorganic phosphate
What is phosphorylation? The process of making ATP
What does cyanide do? Stops ATP production
What is potential energy? Stored energy available to do a reaction.
What is kinetic energy? Active energy, or energy available to do work.
What is a calorie? Measure of energy, defined as the amount of energy required to raise 1cc of H20, one degree celcius.
What is a Kcal? a Kilocalorie, or 1000 calories. dietary calories "Big calorie"
What are anabolic reactions? Building reaction small to large. Ex. photosynthesis
What are catabolic reactions? Breaks down reactions large to small Ex. respiration.
What are endergonic reactions? Energy level of the reactants is less than the energy level of the products, thus energy is required. Ex. photosynthesis
What are exergonic reactions? Energy of the reactants is higher than the products, thus energy is released in the process. Ex. respiration.
What is energy of activation? Energy required or added to start up a reaction process. ex. lighter on a barbecue supplies EoA.
What do enzymes do to the Energy of Activation Minimized it by concentrating the reactants attraction to active sites; could change shape.
What is the Biological Electron Acceptors? NAD
What is NAD? Nicotinamide Adenine Dinucleotide Acts as an electron acceptor in many of the oxidation-reduction reactions associated with cell respiration.
Describe each reactant: NAD + 2e- + H+ ---> NADH- e- = Electrons transferred for energy reactions H+= a Hydrogen ion NAD= Oxidized (no extra electrons) NADH= Reduced has two electrons plus a H+ This compound acts to transfer electrons for biological reactions.
What doe it mean to be hydroscopic? To draw water.
What is oxidation? Loss of electrons
What is reduction? Gain of electrons
What are our energy sources? -Petroleum -Natural Gas -Coal -Electricity -Geothermal -Nuclear -Wind/Solar
What do most carbon compounds produce when burned? CO2 H2O Energy (ATP)
What are the characteristics of enzymes? -Catalyze very specific biological reactions without being altered. -Highly specific in their reactivity. -Has a primary, secondary and tertiary structure. -Can't be used up; recyclable.
What factors affecting enzyme activity are needed for a successful reaction? 1. Concentration of substrates 2. Optimal pH 3. Optimal temperature 4. Appropriate substrate and enzyme concentrations 5. Some enzymes also require co-enzymes to assist the reaction 6. No inhibition
What is the inhibition of enzymes? The blocking or altering of the active site of the enzyme.
What is competitive inhibition? -A different molecule blocks the active site so that the appropriate substrate molecule cannot react. -Reversible because the increasing concentration of the appropriate substrate can overwhelm the presence of the competitor.
What is a non-competitive inhibitor? -A non-substrate molecule binds to another part of the enzyme molecule and the shape of the enzyme and the active site is changed (deformed) and the enzyme is rendered inactive. -May be reversible.
What is feedback inhibition? -Sometimes the product of an enzymatic reaction continue to block the active site which reduces the enzyme reactivity. -When there's too much product molecule, lowering the concentration of the product will open up the active site. -Reversible.
What is the general chemical reaction for photosynthesis? CO2+H2O+sunlight ----> Glucose (C6H12O6) + O2
What is the biological basis for energy transfer? Hydrogen and electrons
How is O2 obtained as a product in photosynthesis? As a result of splitting the water molecule.
What is the electromagnetic spectrum? The range of energy levels in the universe.
From low energy to high energy, what is the electromagnetic spectrum? Radio waves, microwaves, infrared heat, VL, ultraviolet, x-rays, gamma rays
What is the visible spectrum? In the middle of the electromagnetic spectrum Interpreted as light
What are photons? Energy particles of light
What is the energy of the photon dependent on? The wavelength (color)
What wavelengths have more energy and which have less energy? -Shorter wavelengths have more energy (380 nm) -Longer wavelengths have less energy (780 nm)
What are colors of objects due to? The wavelengths not absorbed by the object.
What color reflects all wavelengths? White
What color absorbs all wavelengths? Black
What light contains all wavelengths? White light
What is chlorophyll? Large molecule with a porphyrin group (ring of 4 complex carbon compounds with an atom of Mg in the center and a long carbon tail) Many single and double bonds capable of absorbing energy.
What is chlorophyll responsible for? Absorbing sunlight energy and transferring the energy to charge electrons which are used to split water and produce ATP.
What is the absorption spectrum? Those wavelengths of light absorbed by the pigment.
What are the two main groups involved with the absorption spectrum? 700-650nm / red light 470-430nm / blue-violet light
What is the action spectrum? Those wavelengths of light which result in photosynthesis (measured by production of Oxygen and glucose)
What are carotenes? Orange, yellow pigment
What are xanthophylls? Yellow pigment
What are anthocynanins? orange, yellow, red pigment
What are antennae pigments? Harvest the light energy at wavelengths different from chlorophyll and transfer this energy to chlorophyll.
What purpose do the other pigments in chlorophyll serve? 1. As antennae pigments 2. Protects chlorophyll from UV destruction (oxygenation)
What are phycocyanins? Blue pigment
What occurs in fall when chlorophyl is reabsorbed from the leaves and why? These other pigments are no longer masked and the leaves turn color in order to conserve Magnesium.
What are phycobilins? algal pigments
What is phycoerythrin? Red pigment that acts to harvest wavelengths of light not absorbed by water (primarily green pigments).
What is the excitation of electrons? -Electrons may be boosted to another orbital by the addition of the energy. -Ex. in photosynthesis, chlorophyll electrons are boosted to a higher orbital by the energy from sunlight. -When the electron falls back to original orbital, the energy is released in a usable form.
What is florescence? -Photons of high energy wavelength excite electrons, when they fall back to the original orbital they emit photons of lower energy wavelength. -Reflects UV energy
What is the structure of chloroplasts? -Double membrane organelle -Series of lamellae with stacks of grana collectively called thykaloid disks -Fluid called stroma.
What are lamellae? Continuous membranes inside a chloroplast.
What are grana? Thickened areas of complex membrane.
What do thykaloid disks contain? -chlorophyll -phospholipids -carotenes -proteins
What is the balanced photosynthetic reaction? 6CO2 + 12H20 + sunlight + chlorophyll = 6O2 + C6H12O6 + 6H20
What are the basic components of photosynthesis? 1. Capturing of energy 2. Production of glucose 3. Electron receptor for photosynthesis
Photosynthesis is: Anabolic or Catatonic? Exergonic or Endergonic? Anabolic and endergonic
Respiration is: Anabolic or Catatonic? Exergonic or Endergonic? Catatonic and Exergonic
Where does the photosynthetic reaction take place? On the membranes of the thykaloid disks in the chloroplasts.
What are light dependent reactions? -Water is split to release electrons (also H+) and Oxygen -Light energy is used to excite these electrons -Some of the light energy is used to make ATP by phosphorylation of ADP -Electrons are excited a second time so that they have enough energy to make NADPH, which will be used in the dark reactions along with ATP to make glucose. Water is split and energy is captured from light.
What is cyclic phosphorylation? -Electrons may be reused -Electrons return to chlorophyll, some of their energy is used to generate 1 ATP molecule and can be repeated many times; cyclic.
What is non-cyclic phosphorylation? When both photosystems I and II are intact, most of the electrons are not returned to the original molecules of chlorophyll and are used for ATP production and reduction of NADP.
What is photosystem I? -Uses a type of chlorophyll which traps wavelengths of light of 700nm and so it is called P700. -Excited by sunlight to energize 2 electrons, which are temporarily transferred to another substance called X, which removes the energy from the electrons so they may return to chlorophyll.
What is photosystem II? -Chlorophyll absorbs wavelengths of 680nm (P680) is energized to removed electrons (hydrogens) from water; water is split into H and O. -Electrons are then passed through a series of carrier substances to photosystem I.
Light Dependent Reaction Equation 2H20+2ADP+2Pi+2NADP ---> sunlight and chlorophyll ---> 2ATP + 2NADPH + O2
What are light independent reactions? -Products from light reactions, ATP and NADPH are used to reduce CO2 -Reduction of CO2 results in the formation of glucose. -"Raw materials" ADP and NADP are recycled to return to their light reactions. Energy is used and CO2 is "fixed" into glucose (stored energy)
What is C3 photosynthesis? -"typical" photosynthesis -Two 3-Carbon fragments (phosphoglycerate) are used in these reactions
What is required to make 1 molecule of glucose? The Calvin Cycle 12 NADPH 18 ATP
What is the Light Independent Reaction Equation? Ribulose Diphosphate+CO2+12NADPH+18ATP = ribuluse diphosphate +12NADPH+18ATP+18Pi+6CH2O glucose equivalent
Where does the light independent reaction take place? The stroma of the chloroplast.
What is photorespiration? A process in which products of photosynthesis are metabolized to produce energy. Ex. when plant CO2 levels drop below critical level because of either intense sunlight, high temperature and low humidity, or water loss, it results in the shut down of gas exchange in the leaf because of the closing stomata which the products are cannibalized for their available energy so they they may be produced again.
What is C4 Photosynthesis? -An alternative form of photosynthesis. -CO2 is added to a 3 carbon compound (phosphoenolpyruvate). -New C4 compound is transported to another area of leaf where the CO2 is removed and put into the normal Calvin Cycle. This requires more ATP than usual but do not exhibit photorespiration, and can photosynthesize in adverse conditions. -Has evolved independently in many groups of plants and is found in many tropical plants and grasses such as crab grass and corn.
What are the ecological aspects of photosynthesis? -Plants use different intensities of light -Desert plants use CO2 at night -Aquatic plants absorb red and blue wavelengths -Algae are most efficient at converting sunlight to energy -Dynamic system in regard to changes in the atmosphere.
Why do plants use different intensities of light? Plants have different efficiencies when using light at low intensity. Ex. Shade and Sun plants.
Why do desert plants use CO2 at night? -They incorporate it at night when temperatures and water loss are relatively low. -Carbon dioxide is stored in the form of organic acids at night -During the day these acids are decomposed to released CO2 and photosynthesis proceeds.
Why do aquatic plants absorb red and blue wavelengths? It is absorbed by the water. To compensate for this, algae typically have several pigments which are capable of absorbing the energy of the green and yellow wavelengths.
Why are algae most efficient at converting sunlight to energy? -The range is between 10-40% efficiency. -Most terrestrial plants have an efficiency of only 1-2%. -This increased efficiency of algae is the basis on which some scientists believe that a harvest of algae could feed the world.
Why is photosynthesis a dynamic system in regard to changes in the atmosphere? If the Carbon Dioxide level if increased 12 times (36% of the air), photosynthesis increases by 400-500%. If the water level is adequate, photosynthesis may give a two fold yield. Scientists are excited with the idea of putting a C4 gene into a C3 plant. Result=plants that are very productive and enrich soil in hostile, dry conditions.
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