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EBIO 1210 FINAL EXAM STUDY GUIDE QUESTIONS WITH
ACCURATE ANSWERS
List examples of monosaccharides, disaccharides, and polysaccharides -- Answer ✔✔ monosaccharides: Glucose, galactose, and fructose Disaccharides: lactose, maltose, and sucrose Polysaccharides: the storage forms of glucose in plants and animals predict the formula of sugars composed of more than one monosaccharide -- Answer ✔✔ Disaccharides Formula: C12H22O Disaccharides: consist of two single sugars (two hexoses). a disaccharide is formed when dehydration synthesis joins two monosaccharides Formula: C12H22O explain how high fructose corn syrup causes health problems through its effect on human taste buds, sugar transporters, and the microbiome -- Answer ✔✔ HFCS produced cheaply from corn starch tastes extra sweet: human taste buds detect fructose better than glucose sugar transporters in human gut are slow at taking up extra fructose:
- gut microbes will digest the extra fructose
- depending on gut microbiome, a gas is formed and causes farts and diarrhea
- diarrhea removes essential gut microbes and can lead to mineral deficiencies interferes with oral contraceptive efficiency explain how lactose tolerance is related to lactase production and the human diet over evolutionary history -- Answer ✔✔ lactase in baby guts splits disaccharide lactose in milk into the monosaccharides glucose and galactose in hydrolysis. many adults no longer make this, lactose left in the gut is digested by gut microbes which leads to gas diarrhea and discomfort. lactose intolerance has a genetic component. lactose intolerance is the original human condition for hunter-gatherers. in ancient human
populations that raised dairy cows, adults who were lactose intolerant had a lesser chance of survival and reproduction. some people are lactose tolerant because their ancestors consumed a lot of milk. list the polysaccharides (starch, glycogen, and cellulose) and the organisms in which these are found -- Answer ✔✔ Starch; energy storage cabs in plants glycogen: energy storage carbs in animals Cellulose: major cell wall component for structural support in plants explain how the structures of polysaccharides determine digestibility and function -- Answer ✔✔ glucose can form two different rings: one ring type forms the spiraling helices of the easy to digest storage carbs starch and glycogen. the other ring type forms the straight fibers of the hard to digest structural carb cellulose describe the general structures of the starches amylose and amylopectin and explain the differences in the speed of their breakdown and their effect on blood sugar and fat storage -- Answer ✔✔ amylopectin: highly branched starch found in rice, white flour, or baking potatoes digested very quickly leads to pronounced spikes in blood sugar Amylose: long, unbalanced strands of starch found in beans digests more slowly leads to more balanced blood sugar levels glycogen: humans store highly branched glycogen in liver and muscles a quickly mobilized energy source but also quickly exhausted fat takes a little longer to mobilize, but provides a more lasting energy supply
Explain what happens to the energy of sunlight in the ecosystem with producers and consumers -- Answer ✔✔ Examples of photosynthetic organisms on land and water our plants, photosynthetic protists, and photosynthetic bacteria. Energy enters the system as sunlight. solar energy is converted to chemical energy by producers via photosynthesis. Chemical energy from food is used by consumers to power body functions. Energy leaves the system as heat. Know that photosynthesis produces not only food but also oxygen -- Answer ✔✔ Describe where in a plant photosynthesis takes place in what the inputs and outputs of photosynthesis are as a whole process -- Answer ✔✔ The inputs of photosynthesis are carbon dioxide and water and the outputs of photosynthesis are glucose and oxygen gas. photosynthesis happens in the chloroplast List the specific locations and all inputs and outputs of the light reactions and carbon conversion reactions in the Calvin cycle. -- Answer ✔✔ Inputs: H2O, sunlight , ADP+P, NAPH+ Outputs: O2, ATP, NADPH The energy of the sun is used to make energy-rich ATP this ATP is used to make energy-rich sugars. The hydrogen for carbon-hydrogen bonds in the sugar comes from water. Energized electrons and H+ from water are taken on by NADP + which becomes NADPH and goes on to the Calvin cycle Explain why ATP is not the end product of photosynthesis and why ATP is used to make sugar -- Answer ✔✔ ATP is too unstable to store energy there for carbon- hydrogen bonds in energy-rich molecules like sugars are used to store energy and release the energy again later to form ATP for cellular work inputs and outputs of Calvin cycle -- Answer ✔✔ inputs: CO2, ATP, NADPH outputs: G3P sugar (to make glucose), ADP+P, NADP+ describe what creates electron flow in chloroplast -- Answer ✔✔ sunlight creates a flow of energized electrons along a biological electron transport chain
- powers production of ATP
- provides the energized electrons for C-H bonds
describe the sequence of energy transformation from sunlight to be excited electrons and electron flow, then to a proton gradient, then to ATP and NADPH, and ultimately to sugar molecules -- Answer ✔✔ 1. sunlight energizes electrons of chlorophyll and are continuously replaced by electrons from water
- water is split into electrons, H+ and oxygen
- The energized electron flow through the photosynthetic electron transport chain
- Pump H+ from the stroma into the thylakoid space
- Next, H+ flowing through the ATP synthase turn the turbine
- energized ATP formation by the ATP synthase
- Light energizes electrons again for loading onto NADP+
- NADPH and ATP of to the Calvin Cycle to make sugar explain where and why water is used and oxygen is produced in photosynthesis -- Answer ✔✔ 1. sunlight energizes electrons of chlorophyll and are continuously replaced by electrons from water
- water is split into electrons, H+ and oxygen Explain how active and passive transport are involved in the formation and utilization of a proton gradient across the thylakoid membrane -- Answer ✔✔ electron transport builds a proton gradient by pumping H+ from low concentration in the stroma to ever higher concentration in the internal thylakoid space. protons (H+) flow through the ATP synthase from high to low concentration back in the stroma the ATP synthase turbines utilizes the energy of the proton gradient to form ATP in the stroma Protons (H+) are piled up in the inner thylakoid space like water behind a dam and flow back through the ATP synthase from high to low H+ concentration the ATP synthase turbine utilizes a proton gradient and enables facilitated diffusion explain how and why the plant maintains a source/sink balance between its leaves as the source of sugar and the rest of the plant as a sink for sugars -- Answer ✔✔ plants adjust the growth of leaves/shoot (sugar source) and other non green parts (sugar sink) to match each other for a balanced source sink ratio
cellular respiration -- Answer ✔✔ hemoglobin transports O2 through the blood stream to body cells hemoglobin then transports the CO2 waste produced by the body cells back to the lungs to exhale Hemoglobin’s o2 binding capacity is regulated by CO2 concentration muscles release CO2 from cellular respiration into the blood. CO2 decreases hemoglobin’s O2 binding capacity muscles release CO2 in blood from cellular respiration and causes hemoglobin’s binding capacity of O2 to decrease hemoglobin releases O2 to muscles, Co2 is taken away from muscles by blood fluid, lungs release CO2 into air, the drop in CO2 in the blood increases O2 binding capacity in the lungs , O2 inhaled by the lungs binds tightly to hemoglobin hemoglobin binds O2 in the lungs an releases it into the muscle; binding capacity of hemoglobin for O2 is high in the lungs and low in the muscle region when those muscles are being used describe what happens to the high energy electrons from food molecules in glycolysis and the citric acid cycle -- Answer ✔✔ To produce ATP: energy from a food molecule is converted from one form to another several times each step releases just a little energy step by step sugar breakdown in cellular respiration: to extract high energy electrons sugars are broken down in a series of little steps (starting with glycolysis in the cytosol, continued by the citric acid cycle in mitochondria) NADH shuttles high energy electrons and H+: during the breakdown of sugars, high energy electrons + protons are extracted from C- H bonds. these electrons and protons are transferred to NAD+ to form NADH. NADH delivers high energy electrons to the electron transport chain that pumps protons across a membrane to fuel the synthesis of a lot of ATP CO2 is released as byproduct from mitochondria: by the end of the citric acid cycle, all carbon atoms of the original sugar have been turned into CO
list where in the cell CO2 is released in aerobic cellular respiration -- Answer ✔✔ CO is released as byproduct from mitochondria by the end of the citric acid cycle, all carbon atoms of the original sugar have been turned into CO List the final electron acceptor of the mitochondrial electron transport chain and explain its essential role in ATP production -- Answer ✔✔ the final acceptor oxygen picks up electrons and H+ which forms water NADH delivers high energy electrons into the electron transport chain. oxygen pick up these electrons at the end of the chain, adds 2 H+ and forms H2O with electrons tightly held by oxygen oxygen is the final acceptor of the electron transport chain ATP -- Answer ✔✔ adenosine triphosphate ATP is a ______ -- Answer ✔✔ nucleic acid When one of the three phosphates is broken off ______ -- Answer ✔✔ It releases a lot of energy and becomes Adenosine diphosphate Aerobic cellular respiration (eukaryotes) -- Answer ✔✔ Chemical equation: C6H12O6+6O2 --> 6CO2+6H20+ATP energy Glucose is broken to make ATP energy Steps:
- Glycolysis - takes place in the cytoplasm doesn't require oxygen. glucose turned into pyruvate. Net yield from this step makes 2 ATP and 2 NADH ( coenzyme and transfers electrons)
- Krebs Cycle- "citric acid cycle" now in mitochondria. requires oxygen. initial conversion of pyruvate to Acetyle-CoA which makes 2 NADH before Krebs gets started. pyruvate is oxidized, CO2 is produced, 2 ATP is produced, 6 NADH, and 2 FADH (coenzyme, assists in transferring electrons )
- Electron transport chain- still in mitochondria. still requires oxygen. electrons are transferred from the NADH and FADH and to several electron carriers to create a proton gradient. the protons are used to power the enzyme ATP synthase. ATP
electron acceptor which oxidizes NADH into NAD+. lactate is product and makes muscles sore. Oxygen or Hydrogen has a higher attraction to electrons -- Answer ✔✔ oxygen because it is more electronegative which combo of these atoms H-H O=O and H2O result in bonds with evenly shared electrons or bonds with electrons tightly by oxygen and why -- Answer ✔✔ O=O H-H equal sharing of electrons electrical interactions in hydrogen bonds between water molecules -- Answer ✔✔ d- of H to d+ of oxygen transcription cohesion tension mechanism of water transport in plants -- Answer ✔✔ trees pull up on a string of water from the soil to their tops because water molecules stick to one another through cohesion provided by hydrogen bonds. According to the transpiration-adhesion-cohesion-tension mechanism of water transport in xylem, water evaporating through the stomata produces a tension, or negative pressure, that pulls the water column up the plant. the role of water in evaporative cooling in humans and plants and how cacti are adapted to desert environment -- Answer ✔✔ for every molecule that evaporates from a wet surface, the remaining liquid gets cooler because energy is consumed as a hydrogen bonds are broken. sweating/evaporation keeps many organisms from overheating. humans cool through sweating, leaves cooled by loss of water through tiny leaf pores. cacti in deserts with little soil moisture must conserve water ( no evaporative cooling) instead they are highly heat tolerant. they keep their pores tightly closed during the day. explain the relative attraction for electrons of the atoms sodium and chlorine and why pairing of these atoms result in electrically charged ions. -- Answer ✔✔ Cl has 7/ electrons in its outermost shell and aims to add one electron. Na only has 1/8 possible electrons in its valence shell and is happy to give up the lone electron in order to have a filled out outer shell. The electrical interactions between water molecules and between water and Na+ and Cl- as examples for positively or negatively charged particles. -- Answer ✔✔ they make
a lattice. Sodium is a cation with a +1 charge and chlorine has a - 1 charge making a crystal lattice structure predict how the type of bond formed between two oxygen atoms affect the solubility of oxygen in water and explain how the strong attraction of oxygen for electrons explains its roles in biology. -- Answer ✔✔ oxygen doesn't dissolve in water because it doesn't form hydrogen bonds. in your body, burning of food molecules with O2 releases energy to make ATP. Immune system uses activated oxygen to kill cancer cells and pathogens. antioxidants are needed to terminate the immune attack. oxygen molecule O2 has -- Answer ✔✔ no partial electric charge oxygen doesn't form hydrogen bonds with water -- Answer ✔✔ true deduce from its bonds or electrical charges whether a molecule as a whole is hydrophilic or hydrophobic. -- Answer ✔✔ water soluble = hydrophilic have + or - electrical charges. have positive and negative poles (d- or d+). "polar" with electrons held tightly by oxygen not water soluble = hydrophobic no (or too few) electrical charges (+ or - ) and now and no (or too few) positive and negative poles. they are "nonpolar". molecules are instead primarily composed of bonds with electrons held loosely by C and/or H. to be water- soluble a large molecule needs several points across its structure for formation of electrical interactions with H2O. C-H bonds have -- Answer ✔✔ no d- and d+ regions (neutral) C=O bonds have -- Answer ✔✔ d- and d+ regions water soluble vitamins and water non-soluble vitamins -- Answer ✔✔ Soluble: vitamins form multiple electrical attractions with water and are easily absorbed from supplements Insoluble (fat soluble) : vitamins form no of too few electrical interactions with water and must be eaten with foods containing fats or oils
List the three sub groups of lipids and their functions -- Answer ✔✔ Fats- highest energy content and thus best energy storage Phospholipids- Form biological membranes and provide structural support Steroids- hormones that regulate development and function List the major building block of a fat -- Answer ✔✔ C-H bonds ( with electrons that are loosely held between the atom) can be burned with oxygen to release energy. fats are made from two types of smaller molecules: a glycerol backbone to which 3 fatty acid tails are attached a fat is synthesized from glycerol+ fatty acids removal of H2O in dehydration synthesis forms new bonds between glycerol and fatty acids. predict whether hydrogen bonds can form between a fats fatty acid tails -- Answer ✔✔ hydrogen bonds wont form lipids -- Answer ✔✔ like fats, oils, or waxes consist mainly of bonds between carbon - carbon or bonds between hydrogen - carbon fats, oils, and waxes are very hydrophobic and do not mix with water. This is why oils form films on water. predict how many water molecules are needed to completely break down a fat into its monomers. -- Answer ✔✔ three, water molecules involved in the synthesis or breakdown of a larger molecule is = to the total number of monomer building blocks minus one explain how the differences between saturated and unsaturated fatty acids in the number of C=C and C-H bonds relate to their shape and fluidity. -- Answer ✔✔ kinks mean more fluid, no kinks mean solid describe saturated, monounsaturated, and polyunsaturated fatty acids -- Answer ✔✔ Saturated vs unsaturated fats- saturated = solid unsaturated = liquid at room temp saturated fats have no kinks in their glycerol things
monounsaturated have one kink in their glycerol thingy polyunsaturated have two or more kinks in their glycerol things nucleic acids, proteins, and large carbohydrates all consist of______ -- Answer ✔✔ long strings of monomers ( can all form polymers) lipids are formed from____ -- Answer ✔✔ just a few monomers fats are made by attaching_____ -- Answer ✔✔ 3 fatty acid tails to a glycerol backbone the saturated fatty acid shown is saturated with the maximal number of _____ -- Answer ✔✔ hydrogen atoms and CH-H bonds explain the connection between polyunsaturated fatty acids and defense hormones in plants and animals -- Answer ✔✔ plants make their own PUFAs ( polyunsaturated fatty acids) as needed animals/humans must consume dietary PUFAs to make the PUFA- derived hormones they need to regulate their immune system explain omega - 6 to omega-3 ratio of fatty acids in the diet and uncontrolled inflammation in humans -- Answer ✔✔ omega - 6 - derived prostaglandins trigger the immune response omega- 3 - derived prostaglandins terminate the immune response today’s diet has too much omega-6 PUFA and is deficient in omega-3 PUFA, which leads to chronic inflammation, disease, and poor immunity. uncontrolled inflammation is an attack of the immune system on healthy body cells as occur in an autoimmune disease describe how the structure of phospholipids, the electrical charges in their head groups, and hydrophobic bonds in their tails relate to their function in biological membranes. -- Answer ✔✔ phospholipids = phosphate+glycerol+2fatty acid tails(look like sperm with two tails) phospholipids form all biological membranes, the tails form an impenetrable barrier to most molecules.
polyunsaturated fatty acids offer more benefits for membranes o plants and microbes in cold places at _____ temp, membranes become too fluid at _____ temp, membranes become too rigid -- Answer ✔✔ hot cold when cold plants and microbes adjust their membranes to become more _____ -- Answer ✔✔ fluid at cold temp predict how a cell can increase fluidity of its membranes -- Answer ✔✔ increase the number of unsaturated fatty acids explain the role of cholesterol in membrane fluidity -- Answer ✔✔ acts as a temp buffer prevents hydrophobic tails from packing too closely increases fluidity at low temp limits lateral phospholipid movement stabilizes membranes at high temp describe how hydrophilic and hydrophobic molecules move across biological membranes and why -- Answer ✔✔ small hydrophobic molecules slip through a phospholipid bilayer of membranes with no help from proteins.( like oxygen) hydrophilic molecules cant slip through the bilayer
- they can only move from one side to the other with the help from transport proteins that span the entire membrane predict where amino acids with hydrophilic or hydrophobic side chains are found in proteins that transport substances across membranes -- Answer ✔✔ the building blocks (monomers) of proteins are amino acids amino acid sequence = primary structure of a protein the side chains on amino acids act like the ridges on a key- interact with other molecules to unlock the shape of a protein dehydration synthesis of proteins to amino acids
list the major human organs in which aquaporins play a role -- Answer ✔✔ mouth- regulation of saliva output stomach, small intestine - secretion of aqueous gastrointestinal juices during digestion Kidneys- concentration of urine lungs- lung hydration eyes- keep eyeballs moist; tears skin- aquaporins needed to cool body by sweating to allow passage of H2O molecules, the amino acids in aquaporins outer middle regions( in contact with membrane fatty acid tails) have to be _____ and the amino acids lining the proteins inner channel and its top and bottom portions have to be ____ -- Answer ✔✔ hydrophobic, hydrophilic explain how hydrophobic and hydrophilic substances are transported through the blood stream -- Answer ✔✔ water insoluble vitamins are transported through the bloodstream by proteins the inside of the barrel shaped protein that carries water insoluble vitamins through the water based fluid consist of hydrophobic amino acids, while its outside portions in contact with the blood fluid consists of hydrophilic amino acids water soluble vitamins move through the water based fluid without the help of proteins ( they just dissolve in the fluid) explain the role of the low density lipoprotein (LDL) in heart disease -- Answer ✔✔ Steroid cholesterol is transported in the bloodstream by LDL. LDL is like a life raft; it touches the water on all sides and shelters the water insoluble lipid inside the inside of the barrel shaped LDL protein consists of hydrophobic amino acids while the outside part consists of hydrophilic amino acids. cholesterol is removed from arteries by removing LDL from blood stream. the removal is inefficient in individuals with hypercholesterolemia.
facilitated diffusion- allows hydrophilic substances to reach the same concentration on both sides of the membrane. moves with the concentration gradient. no energy (passive transport) proteins help molecules pass through the membrane. examples are H+ or Na+ or Ca2+ during muscle relaxation. collapsing a gradient of a hydrophilic substance requires a facilitating protein but not energy input. protein is needed to move substances across membranes- polar molecules or molecules that are too big( like glucose). collapsing a gradient of a hydrophilic substance requires a facilitating protein but not energy input. when ATP energy from the cell is needed- the movement of molecules from low to high concentration( takes energy). Active transport. accumulation of a substance on one side of a membrane requires a pump and energy (ATP) to fuel the pump. building gradients -- Answer ✔✔ our bodied build gradients to utilize these gradients to contract muscles or produce nerve impulses. describe the role of the Ca2+ pump in accumulating Ca2+ on one side of a membrane and the role of the Ca2+ channel collapsing this gradient during muscle function. -- Answer ✔✔ a muscle cell uses Ca2+ to connect muscle fibers for muscle contraction. calcium is stored in a membrane surrounded pouch (sarcoplasmic reticulum=SR) in the muscle cell. a nerve signal initiates muscle contraction by opening Ca2+ channels in the membrane of the pouch (SR) to let calcium flow out of the pouch and into the cytosol. Sudden appearance of Ca2+ in the cytosol of the muscle fiber allows thin and thick filaments to bind to each other and pull past each other ( contracts the muscle). muscle relaxation is promoted by Ca2+ channel closure and the pumping of Ca2+ back into the SR pouch with the help of ATP fueled calcium pump. Summarize the conversion of ATP energy to an energy-containing gradient and on to heat energy. -- Answer ✔✔ muscle relaxation is promoted by Ca2+ channel closure and the pumping of Ca2+ back into the SR pouch with the help of ATP fueled calcium pump. the gradient is built with ATP energy. when the gradient is utilized, its energy is converted into unusable heat.
explain the role of the Na+/K+ pump and of Na+ and K+ channels in building gradients in nerve function -- Answer ✔✔ the Na+/K+ pump builds gradients of two substances Na+ and K+ Na+ is pumped from low concentration inside the cell to high concentration outside the cell K+ is pumped from low concentration outside the cell to high concentration inside the cell. the Na+/K+ pump builds an electrochemical gradient. the rapid collapse of this gradient forms an action potential= nerve impulse. Compare the roles of pumps and channels in nerve and muscle function -- Answer ✔✔ the Na+/K+ pump builds an electrochemical gradient. the rapid collapse of this gradient forms an action potential= nerve impulse. Na+ and K+ channels utilize their gradients across the nerve cell membrane to generate a nerve impulse. Ca2+ channels utilize the gradient across the SR membrane to trigger muscle contraction. the electrical part of the gradient: -- Answer ✔✔ more positive charges on the outside of the cell because for every 2K+ accumulates inside, 3Na+ are accumulated outside the cell list three major building blocks of ATP, which part of ATP is a nucleotide, and the three kinds of cellular work fueled by ATP -- Answer ✔✔ building blocks - three phosphate groups, each phosphate group adds more negative charges that repel each other. cellular work fueled- transport work, ATP energy is used to build gradient of Na+ K+ or Ca2+. Chemical work, ATP energy is converted to chemical energy of large molecules. Mechanical work, muscle contractions, movement of vesicles explain what features of ATP make it a good energy donor to fuel cellular work -- Answer ✔✔ three phosphates, C-H bonds Describe the position of ATP between energy providing pathways that drive ATP formation and energy requiring processes fueled by ATP -- Answer ✔✔
