Biology Questions

E coli uses which of the following enzymes to regulate membrane fluidity Glucose 6 phosphatase Desaturase Fatty acid convertase Gangliosidase

The backbone of phospholipids is Oglycerol Opolar phosphate head disaccharide chains a protein core

Elastin molecules are crosslinked to each other by covalent bonds between lysines covalent bonds between prolines hydrogen bonds between hydroxylysines and hydroxyprolines hydrophobic interactions between hydroxyprolines and glycines

Cerebrosides are prominent in membranes of kidney cells liver cells brain and nerve cells O O cardiac muscles

obligate aerobes cancer cells facultative organisms obligate anaerobes Question 40 1 point 1 Listen Which of these is NOT a key enzyme in glycolysis phosphofructokinase 1 hexokinase Opyruvate kinase

Which of the following would you expect to find predominating in the plasma membrane of a unicellular eukaryotic organism thriving in glacier ice 20 carbon long saturated fatty acids 18 carbon long saturated fatty acids 18 carbon long fatty acids with 1 double bond 16 carbon long fatty acids with 3 double bonds

The sequential process of fatty acid catabolism to acetyl CoA is called the citric acid cycle the glyoxylate cycle the oxidative phosphorylation pathway the B oxidation pathway

Consider the following list of phosphorylated compounds with their free energies of phosphate hydrolysis Glucose 1 phosphate 5 0 kcal mol PEP 14 8 kcal mole ATP 7 3 kcal mol Which of these molecules could phosphorylate an unknown compound whose free energy of phosphate hydrolysis is 10 3kcal mol Glucose 1 phosphate only PEP only ATP only All three could phosphorylate the unknown compound

A cell biologist exposes both sides of a membrane to a fluorescent chemical that nonspecifically labels proteins exposed to the aqueous solvent but not portions of those proteins exposed to the interior of the membrane environment Which of the following proteins would NOT be labeled on both sides of the membrane multipass a multisubunit protein that is extractable only by using detergent singlepass an integral monotopic protein

Aerobic respiration generates up to 24 38 2 16 ATP molecules per glucose molecule

While investigating a medical condition you discover that the patient has an defective fibroblasts This disorder would most likely affect annulus formation hyaluronate lubrication of joints collagen production primary cell wall deposition

During oxidative phosphorylation protons are pumped into intermembrane space of the mitochondria matrix of the mitochondria ribosomes O cytosol

Each of the following molecules is an electron carrier in the electron transport system except iron sulfur proteins coenzyme A iron containing cytochromes flavoproteins

Which of the following functions like a fence to block membrane protein movement between the apical and basolateral regions of an intestinal epithelial cell plasma membrane Gap junctions Desmosomes Adherens junction

Which of the following aspects of collagen would be directly affected by a defect in procollagen peptidase Synthesis Secretion Extracellular assembly Binding to fibronectin

Which of the following is associated with the lubrication of joints Keratan sulfate Lignins Pectins

Polarized cells are characterized by being surrounded on all sides by a basement membrane random orientation within a tissue distinct apical and basolateral ends of the cell Ojunctions only to ECM and not to other cells

Each of the following cell junctions is found in intestinal epithelial cells except gap junctions tight junctions desmosomes plasmodesmata

N CAM mediates interactions between neural cells and is a member of which of the following protein families Immunoglobulin superfamily IgSF proteins Catenins Lectins

The composition of the outer and inner monolayers of cell membrane lipid bilayers is identical in each monolayer highly random for each monolayer asymmetrical i e different in each monolayer lipids are twice as concentrated in the inner monolayer as in the outer monolayer

Fermentation directly Oregenerates NADH from NAD Oregenerates NAD from NADH Ogenerates ATP produces acetyl CoA

X ray crystallography can be used to determine fatty acid composition of cell membranes O determine carbohydrate structures determine the structure of proteins determine phospholipid composition of cell membranes

Regarding oxidative phosphorylation all is true EXCEPT ATP synthesis is dependent on electron transport uncouplers allow continued electron transport in the absence of ATP synthesis electron transport is dependent on ATP synthesis it involves the creation of a proton pump gradient

Each of the following is true about basal lamina except it underlies epithelial cells it serves as a structural support it is composed primarily of fibronectin it contains collagen type IV proteoglycans laminins and entactin

Pyruvate can be a substrate or product involved in each of the following except Ofermentation aerobic glycolysis glucose oxidation cheminsmoric

Why are mitochondria so prevalent in skeletal muscle Mitochondria produce energy anaerobically O Mitochondria provide energy for muscle contraction Mitochondria provide the muscle elasticity to contract Mitochondria are primarily involved in repairing damage accumulated during exercise

Which of the following is NOT true of the citric acid cycle it serves to provide a majority of reduced coenzymes to the electron transport system it produces CO2 it serves to produce a small amount of ATP All of the above is true

Bacteriorhodopsin is a protein fatty acid anchored single pass Omultipass GPl anchored

Connexin is part of the structure of tight junctions cadherins adherens

PFK 2 is involved in allosteric regulation of CAMP PFK 1 Epinephrine Glucagon

Membrane phospholipids are asymmetrically oriented in phospholipid bilayers as a result of the ease or restriction of mobility with respect to the plane of the membrane Which of the following is NOT a correct thermodynamic interpretation of the phospholipid bilayer structure and asymmetry Phospholipids generally can rapidly rotate about their long axis to help increase the entropy of the system Phospholipids can rapidly exchange places with lateral neighboring phospholipids within the same leaflet of the bilayer to help increase the entropy of the system Phospholipids can rapidly flip flop from one leaflet or monolayer of a bilayer to another to decrease the enthalpy of the system Phospholipid polar head groups face outward to contact the aqueous environment to help decrease the enthalpy negative AH of the membrane solvent system

Transmembrane segments of membrane proteins can contribute to all of the following functions EXCEPT O facilitating exocytosis transporting solutes from outside to inside the cell serving in signal transduction across membranes serving as targets for glycosylation

A useful technique for studying membrane proteins is gel electrophoresis This technique utilizes an electric field to separate membrane proteins based on which property hydropathy index number of membrane spanning domains degree of unsaturation size

Which of the following junctions is most abundant in tissues such as skin that are required to resist significant mechanical stress Gap junctions Desmosomes Focal adhesions

Consider the three phases of glycolysis 1 preparation and cleavage Gly 1 to Gly 5 2 oxidation Gly 6 to Gly 7 3 pyruvate formation Gly 8 to Gly 10 Which of these phases produces ATP 01 1 and 2 O2 and 3 0

You discover a dog suffering from an autoimmune response On further investigation you find that the cells of various tissues are loosely arranged and do not have characteristic shapes and the animal is prone to hemorrhaging because of poor blood clotting Based on these results the target of the autoimmune response is most likely to be O extensins laminins fibronectins

The ATP high energy or energy rich bonds are which of the following types of bond Hydrogen Phosphoester lonic Phosphoanhydride

During aerobic respiration the majority of the energy of glucose is stored in coenzymes NADH and FADH2 ATP formed during glycolisis ATP formed during citric acid cycle oxygen

12 12pts Draw the acyl enzyme intermediate for the serine protease catalyzed cleavage of a peptide Draw out the mechanism for the remainder of the reaction Be sure to provide the complete structure of the peptide R for amino acid side chains Describe the role of Asp in the catalytic triad

Question 12 Match the column of the bacterial example to its importance in bioremediation Alcanivorax borkumensis Genera Pseudomonas Genera Rhodococcus 0 25 pts Choose Choose Degrade aromatic compounds found in oil into carbon dioxide Their surfactants solubilize hydrophobic substances in oil to access degradation by other microb Degrade HUB harmful algal blooms to remove the water toxicity

Where on the ATP molecule does the release of energy happen i i i HO P O P O P O OH OH Source Wikipedia On the release of Adenine OH O On the release of the first phosphate On the release of the last phosphate O On the release of the ribose sugar OH OH NH N

Analyze the picture below What type of enzymatic regulation is this Altererd active site Substrate Active site Source Chegg com Competitive inhibition Allosteric activation O Allosteric inhibition Enzyme Activator

Question 10 What one carbon molecule is produced when carbon dioxide is used as the final electron acceptor in anaerobic environments Methane Methanogens Methanogenesis 0 0 25 pts Carbon dioxide gas

Which of the following are xenobiotics Mark all that apply Oil and petroleum products Dyes Lubricants Pesticides Paint 0 0 25

The following excerpt comes from the article Microbial Biodegradation of Toxic Waste Bioremediation by Sarah Moore News Medical Life Sciences May 17 2021 E Is this an example of in situ or ex situ bioremediation Interestingly while there are no other natural organisms that downgrade mercury there are several that transform it into a more dangerous substance known as methylmercury Often at industrial sites ionic or elemental mercury is discharged and converted into methylmercury by microbes which then accumulates in the environment and enters the food chain The genetically modified bacteria developed by the team at the Inter American University of Puerto Rico could address this issue by degrading the mercury discharged at such sites before it is converted into methylmercury To achieve this the team is developing a method of adding their modified bacteria into water filters at industrial sites to remove the mercury from the water before it enters the surrounding environment Ex situ In situ

Question 3 Match the terms on the left to the correct explanation on the pull down menu Enzymes Activation energy Active site Conformational change Question 4 0 5 pts Choose Choose Biological catalysts Substrate s modification that uses the enzyme Site where the substrate binds Enzymatic structural modification that causes the substrate s change Energy required to initiate a chemical reaction 0 5 pts

What is the name of the molecule below 1 What is the name of the structure A 2 A D B O 1 ADP 2 adenine O 1 ATP 2 adenine O 1 ADP 2 adenosine O 1 ATP 2 ribose sugar O 1 ADP 2 ribose sugar P

What are the similarities between the energy molecules ATP and NADH Mark all that apply The table show the structural formulas of ATP and NADH Energy Molecules 1 Energy Molecule 2 OH OH H D Ra ATP OH OH Source Wikipedia Both have adenine Both have two ribose sugars NH ofa O P O O OH OH OH OH NADH Source Wikipedia NH NH

Among the temperatures tested which explanation best explains inactivation of catalase A inactivation of the enzyme would occur at 37 C and higher temperatures because catalase is found naturally in a cooler environment B inactivation would occur at 100 C because the structure of the enzyme could not be maintained at this temperature C inactivation would occur at 0 C because the structure of the enzyme could not be maintained at this temperature D it should never be totally inactivated

Both PSI an PSII are Involved Only PSI is involved Cyclic Photophosphorylation NONCYClic Photophosphay Electron expelled from Chlorophyll is cycled back Photolysis of water by the DEC replaces electron to Chlorophyll Oxygen is released from the photolysis of water NADP is reduced to NADPH lation