Mastering Biology (EBIO 1210)
In four of the five pairs of organisms or pairs of organelles below, one produces energy-rich food molecules and oxygen, and the other produces CO2 and H2O. Find the EXCEPTION. chloroplasts and mitochondria in a green leaf cell a plant and a mouse enclosed in a tightly-sealed glass container exposed to sunlight plants and animals in an ecosystem a rabbit and a fox grass and a cow
a rabbit and a fox
In molecular terms, a gene is best defined as the DNA molecule in a chromosome. a sequence of DNA that codes for a protein. an enzyme. a signal to stop translation. several introns bonded together.
a sequence of DNA that codes for a protein.
Non-polar covalent bonds form between atoms with a similar, or the same, degree to which they attract electrons. an intermediate difference in the degree to which they attract electrons. the largest difference in the degree to which they attract electrons.
a similar, or the same, degree to which they attract electrons.
The four major classes of lifes large biological molecules do NOT include nucleic acids. amino acids. proteins. lipids. polysaccharides.
amino acids
Which molecules can be utilized (directly or after some breakdown) in the cellular respiration pathway to generate ATP energy? only amino acids and proteins only glycerol and fatty acids only glucose and sucrose only glycerol, fatty acids, glucose, sucrose, starch, and glycogen amino acids, protein, glycerol, fatty acids, glucose, sucrose, starch, and glycogen
amino acids, protein, glycerol, fatty acids, glucose, sucrose, starch, and glycogen
Four of the five processes below are fueled by ATP formed in mitochondria. Which is not fueled by ATP? -transport of substances from low to high concentration across the outer cell membrane -movement of a vesicle along a cytoskeletal track -transport of protons (H+) from low concentration in the mitochondrial matrix to high concentration in the mitochondrial intermembrane space -chemical work -phosphorylation of a cytosolic protein
transport of protons (H+) from low concentration in the mitochondrial matrix to high concentration in the mitochondrial intermembrane space
The uncoupling protein converts the energy provided by ______ to _______. glucose; ATP ATP; heat glucose; heat pyruvate; ATP pyruvate; NADH
glucose; heat
The movement of protons (H+) through the ATP synthase occurs from ______ to ______ proton concentration. high; low low; high high; high low; low
high; low
Which of the following functions do RNA molecules perform during transcription? Which of the following functions do RNA molecules perform during transcription? catalyzing the formation of bonds between amino acids carrying amino acids providing a site for building a protein holding a "message" from the DNA all of these answers
holding a "message" from the DNA
Which of these is a source of lactose? plant cell walls milk table sugar potato starch glycogen
milk
In mitochondrial electron transport, water is formed. Where does the oxygen for the formation of water come from? carbon dioxide (CO2) glucose (C6H12O6) molecular oxygen (O2) ethanol (C2H5OH) lactate (C3H5O3-)
molecular oxygen (O2)
Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules? steroids lipids nucleic acids proteins fats
proteins
What information is coded in the genes? The blueprint for making proteins fats carbohydrates amino acids nucleotides
proteins
What membrane structures carry out active transport? cholesterol the lipid bilayer proteins on the membrane surface proteins that span the membrane aquaporins
proteins that span the membrane
Enzymes are carbohydrates. proteins. nucleic acids. lipids.
proteins.
The polysaccharides used for energy storage should be expected to be _______ to break down. difficult easy
easy
Carbohydrates are burned in cellular respiration for the purpose of producing oxygen. energy for the cell. water. carbon dioxide. sugars.
energy for the cell.
Glycogen functions in energy storage in animals. energy storage in plants. providing structural support in plant cell walls. providing structural support in animal cells.
energy storage in animals.
Starch functions in energy storage in animals. energy storage in plants. providing structural support in plant cell walls. providing structural support in animal cells.
energy storage in plants.
Cholesterol is the starting material (also called building block or "precursor") for which of the following substances? only estrogen and testosterone only fats estrogen and testosterone, steroid stress hormones, and fats only steroid stress hormones estrogen and testosterone, steroid stress hormones, but not fats
estrogen and testosterone, steroid stress hormones, but not fats
Four of the five features below are characteristics of C-H bonds. Which option below is not. nonpolar high chemical potential energy relatively low stability low chemical potential energy can be burned to carbon dioxide and water
low chemical potential energy
Carbon dioxide and water share four of the following properties. Which is NOT a feature shared by these two molecules? low reactivity low stability polar covalent bonds low chemical potential energy formed when hydrocarbons are burned with oxygen
low stability
The light-driven movement of protons (H+) from the stroma to the inner thylakoid space across the thylakoid membrane occurs from ______ to ______ proton concentration. high; low low; high high; high low; low
low; high
In what type of cells do you expect to find a particularly high level of smooth ER? Cells of (1) the ovaries, (2) the testes, (3) the adrenal gland that produces steroid stress hormones. only 1 only 2 only 3 only 1 and 3 1, 2, and 3
1, 2, and 3
The percentage of the adenine (A) nucleotide in a particular organism's genome is 30%. The percentages of the other nucleotides must be approximately The percentage of the adenine (A) nucleotide in a particular organism's genome is 30%. The percentages of the other nucleotides must be approximately 70% T, 0% G, 0% C 30% T, 20% G, 20% C 20% T, 30% G, 20% C not enough information given the question is nonsense; all nucleotides must account for 25%, due to complementarity in the double-stranded DNA molecule
30% T, 20% G, 20% C
High-fructose corn syrup consists of 100% fructose. 60% fructose and 40% glucose. 55% fructose and 45% glucose. 50% fructose and 50% glucose. 45% fructose and 55 glucose.
55% fructose and 45% glucose.
A polyunsaturated fatty acid with four C=C bonds has how many hydrogen atoms compared to a saturated fatty acid with the same number of carbon atoms? While the number of C=C bonds is different, the number of H atoms is the same. 8 less 8 more 4 less 4 more
8 less
The energy content per gram for fats, carbohydrates, and proteins is about how many kcal/gram, respectively? 9; 9; 9 4; 4; 4 9; 4; 4 4; 9; 4 4; 4; 9
9; 4; 4
Four of the statements below apply to microbes and humans. Find the one that is false. The microbial cells living in the human body outnumber the human cells. Most of the microbes found in the human body are beneficial. The human diet affects the microbial composition of the human gut. A healthy human does not house more than a few hundred microbial cells. Many fermented food products are produced using live microbes.
A healthy human does not house more than a few hundred microbial cells.
The following molecules each contain either no, one, two, or three phosphate groups. Which one contains exactly two phosphate groups? ATP ADP AMP adenosine phospholipid
ADP
Which of the events listed below is part of the light reactions of photosynthesis? Light is absorbed and used to extract electrons from sugar. ADP is phosphorylated to form ATP. Carbon dioxide is incorporated into a sugar. NADP+ is produced. Water is produced.
ADP is phosphorylated to form ATP.
Predict which in the group of AMP, ADP, and ATP has the lowest chemical potential energy? ATP ADP AMP They all have similar chemical potential energy.
AMP
Which of the following is least stable? sugar ATP glucose AMP cellulose
ATP
The light reactions convert the high potential energy of energized electrons to the energy stored in ATP and NADPH ATP and sugars CO2 and sugars ATP and H2O NADPH and H2O
ATP and NADPH
Four of the following statements are correct. Find the one that is FALSE. While performing photosynthesis during the day, the chloroplasts of a green leaf produce ATP to be used in the Calvin cycle. ATP as an energy source for the roots of the plant. sugars for the green leafs cellular respiration at night. sugars as an energy source for the roots of the plant. sugars to fuel the growth of the plant.
ATP as an energy source for the roots of the plant.
The components of which metabolic process are bound to membranes? glycolysis alcohol fermentation ATP formation by the ATP synthase lactic acid fermentation citric acid cycle
ATP formation by the ATP synthase
Prokaryotes carry out all of the following except active transport of substances across membranes. movement work using motor proteins. ATP formation using energy sources from the environment. ATP formation in chloroplasts. energy-dependent synthesis of large molecules.
ATP formation in chloroplasts.
Four of the following statements regarding ATP are correct. Which one is FALSE? ATP powers transport work, chemical work, and movement work. ATP provided by mitochondrial electron transport energizes C-H bond formation in the citric acid cycle. ATP provided by photosynthetic electron transport energizes C-H bond formation in the Calvin cycle. Regeneration of ATP from ADP and phosphate in animal cells occurs in the mitochondria. ATP is very unstable.
ATP provided by mitochondrial electron transport energizes C-H bond formation in the citric acid cycle.
The energy for active transport across membranes comes from the transport protein. the transported substance. ATP. the concentration gradient (gradient in potential energy) of the transported substance.
ATP.
Practice exam question. Four of the following statements accurately describe how various living organisms keep their membranes at an appropriate fluidity to function. Which statement is FALSE? -Mammals invest energy to regulate body temperature. -Humans must acquire fatty acids essential for optimal membrane protein function with the diet. -All organisms are capable of synthesizing all fatty acids they require for optimal membrane protein function. -Cholesterol optimizes membrane fluidity of mammals. -Plants alter the fatty acid composition of membrane phospholipids.
All organisms are capable of synthesizing all fatty acids they require for optimal membrane protein function.
What results from the removal of hydrogen atoms from the fatty acid tails of saturated fat? -An increase in the number of carbon-carbon double bonds in the fat molecules. -A decrease in the number of carbon-carbon double bonds in the fat molecules. -The fat becomes more solid. -A decrease in the number of bends, or kinks, in the fatty acid tails. -Burning of the fat with fewer hydrogen atoms will release more energy.
An increase in the number of carbon-carbon double bonds in the fat molecules.
What makes carbohydrates and fats a source of energy? Both have a lot of oxygen atoms. Both have a lot of bonds with loosely held electrons. Both are hydrophobic molecules. Both form hydrogen bonds with water. Both have a lot of bonds with tightly held electrons.
Both have a lot of bonds with loosely held electrons.
Predict how Na+ and K+ rush through their channels when these channels suddenly open as a nerve impulse (action potential) travels along an axon. Both move by facilitated diffusion. Both move by active transport. Na+ moves by facilitated diffusion; K+ moves by active transport. K+ moves by facilitated diffusion; Na+ moves by active transport.
Both move by facilitated diffusion.
The main final energy-rich product of photosynthesis is ________ and the main energy source obtained by consumers from their food is ________. ATP; ATP ATP; water CO2; C-H bonds of food molecules C-H bonds of sugars; C-H bonds of food molecules sunlight; C-H bonds of food molecules
C-H bonds of sugars; C-H bonds of food molecules
The molecular formula for glucose is C6H12O6. What would be the molecular formula for a disaccharide linking two glucose molecules via dehydration synthesis? C2H4O2 C6H24O12 C12H24O12 C12H22O11 C12H20O10
C12H22O11
The formula for the sugar ribose is C5H10O5. What would be the formula of a trisaccharide made from three ribose monomers? C15H30O15 C15H34O17 C15H26O13 C15H32O16 C15H28O14
C15H26O13
What causes kinks in fatty acids? C=C double bonds C-H bonds C=O double bonds C-C bonds O-H bonds
C=C double bonds
The Calvin cycle converts _______ to _______. C-H bonds; C=O bonds carbon dioxide; water C=O bonds; C-H bonds C-H bonds; carbon dioxide water; carbon dioxide
C=O bonds; C-H bonds
Practice exam question. Use the polarity of the four molecules below to predict which ones can, or cannot, pass directly through the phospholipid bilayer of a biological membrane. -CH4 or H2O can pass through the bilayer, whereas Na+ or a fatty acid cannot. -CH4 or a fatty acid can pass through the bilayer, whereas Na+ or H2O cannot. -CH4 or Na+ can pass through the bilayer, whereas a fatty acid or H2O cannot. -H2O or a fatty acid can pass through the bilayer, whereas Na+ or CH4 cannot.
CH4 or a fatty acid can pass through the bilayer, whereas Na+ or H2O cannot.
From where does the CO2 released in cellular respiration come? CO2 is formed when oxygen combines with the carbon atoms of glucose in the mitochondrial matrix. CO2 is formed when oxygen accepts the electrons from the mitochondrial electron transport chain. CO2 is what is left over from the carbon chain of glucose after the loss of H (electrons and H+). CO2 is formed by extraction of electrons from water in the presence of glucose. CO2 is released in the Calvin cycle.
CO2 is what is left over from the carbon chain of glucose after the loss of H (electrons and H+).
Four of the findings below provide evidence in support of the endosymbiont theory of eukaryote evolution. Find the exception. double membrane around chloroplast DNA in mitochondria DNA in chloroplasts DNA in nucleus ribosomes in mitochondria
DNA in nucleus
Which of the following describes the flow of information in eukaryotic cells? DNA →RNA →proteins RNA →proteins →DNA proteins →DNA →RNA RNA →DNA →proteins DNA →proteins →RNA
DNA →RNA →proteins
Which of the following statements best summarizes the relationship between dehydration synthesis and hydrolysis? -Dehydration synthesis creates polymers and hydrolysis creates monomers. -Dehydration synthesis breaks down monomers and hydrolysis creates polymers. -Polymer breakdown occurs by water removal and polymer synthesis occurs by water addition. -Dehydration synthesis breaks down polymers and hydrolysis creates monomers.
Dehydration synthesis creates polymers and hydrolysis creates monomers.
DNA replication is said to be semiconservative. What does this mean? DNA replication is said to be semiconservative. What does this mean? The old double helix is degraded, and half of its nucleotides are used in the construction of two new double helices. Each new double helix consists of one old and one new strand. One of the two resulting double helices is made of two old strands, and the other is made of two new strands. One strand of the new double helix is made of DNA, and the other strand is made of RNA. Half of the old strand is degraded, and half is used as a template for the replication of a new strand.
Each new double helix consists of one old and one new strand.
What makes a motor protein move along a cytoskeletal track? It is able to move without energy input. Energy is provided by the cytoskeletal track. Energy is provided by ATP. Energy is provided by the motor protein. Energy is provided by the vesicles that are moved.
Energy is provided by ATP.
The three domains of life are plants, animals, and protists. fungi, plants, and animals. prokaryotes, plants, and animals. Archaea, bacteria, and animals. Eukarya, Archaea, and bacteria.
Eukarya, Archaea, and bacteria.
Which of the following statements correctly describes the endosymbiont theory? -Eukaryotes acquired their mitochondria by engulfing photosynthetic prokaryotes. -Eukaryotes acquired their chloroplasts by engulfing non-photosynthetic prokaryotes. -Eukaryotes acquired their mitochondria by engulfing other eukaryotes. -Prokaryotes are eukaryotes that ejected their mitochondria. -Eukaryotes acquired mitochondria and chloroplasts by engulfing prokaryotes.
Eukaryotes acquired mitochondria and chloroplasts by engulfing prokaryotes.
TRUE or FALSE? Rapid plant growth causes sugar build-up in the leaves. True False
False
True or False? Judging from the structure of a fat, one should expect lots of hydrogen bonds between the fatty acid chains. True False
False
True or false? If ATPs third phosphate group were more tightly attached, ATP would be an even better energy donor. True False
False
True or false? To calculate how many C, H, and O are in a polysaccharide, one can simply multiply the C, H, and O present in each monomer by the number of monomers contained in the polysaccharide, and then ADD one H2O molecule for every monomer. True False
False
What holds the two strands of a DNA molecule together? What holds the two strands of a DNA molecule together? Ionic bonds between negatively and positively charged ions Covalent bonds between sugars and phosphates Brüno's interactions Hydrogen bonds between complementary base pairs
Hydrogen bonds between complementary base pairs
Four of the five statements below correctly describe the features of a polyunsaturated fatty acid. Find the one statement that is NOT true for a polyunsaturated fatty acid. -It is fluid at room temperature. -It has two or more kinks. -It has two or more C=C bonds. -It has more C-H bonds than a monounsaturated fatty acid with the same number of C atoms. -It has a lower energy content than a saturated fatty acid with the same number of C atoms.
It has more C-H bonds than a monounsaturated fatty acid with the same number of C atoms.
Which statement below about hydrogen (H) in photosynthesis and respiration is FALSE? Photosynthesis and respiration both use H shuttles. H is removed from water to make sugars in photosynthesis; H removed from sugars is combined with oxygen in respiration, forming water again. NADH is used in photosynthesis; NADPH is used in respiration. The O-H bond is polar; the C-H bond is nonpolar. While the O-H bond cannot be used to release energy, the C-H bond can be used to release energy.
NADH is used in photosynthesis; NADPH is used in respiration.
Four of the molecules or states below represent states of high energy (high potential energy or high chemical potential energy). Find the EXCEPTION. NADH NADP+ ATP sugar a rock sitting on top of a tall structure
NADP+
Which organisms use mitochondria to produce oxygen? plants and animals bacteria and fungi Archaea and bacteria bacteria and protists No known organisms
No known organisms
Practice exam question. Three of the following movements across the cell membrane require a protein (either a protein facilitating diffusion or an energy-driven protein pump). Which does NOT require a protein? Movement of -hydrophilic glucose along its concentration gradient. -O2 from high to low concentration. -H2O from high to low concentration. -Na+ from low to high concentration.
O2 from high to low concentration.
Which of the following lists the steps involved in DNA replication in the correct order? Which of the following lists the steps involved in DNA replication in the correct order? Open DNA double helix → RNA primer synthesized → mRNA synthesized → RNA replaced with DNA Open DNA double helix → RNA primer synthesized → DNA synthesized → RNA primers replaced with DNA Open DNA double helix → DNA primer synthesized → mRNA synthesized Assemble the ribosome → scan mRNA for start codon → make DNA copy from mRNA Transcription factors bind to promoter → RNA polymerase copies all the genes
Open DNA double helix → RNA primer synthesized → DNA synthesized → RNA primers replaced with DNA
Which of the three options below correctly describe the advantages of constructing lifes large molecules from small building blocks. Option 1: A no-longer-needed molecule can be broken down and a different one constructed from the same building blocks. Option 2: A great variety of large molecules can be constructed from a small number of building blocks. Option 3: An animal can eat a plant, break down the plants large molecules to its building blocks and use these to construct its own large molecules. Options 1, 2, and 3 Only option 1 and 2 Only option 1 Only option 2 Only option 3
Options 1, 2, and 3
Which statement about the transport and use of oxygen in humans is FALSE? Oxygen for cellular respiration is taken up by the lungs. Hemoglobin transports oxygen from the lungs to body cells requiring ATP for cellular work. Oxygen serves as the terminal electron acceptor in mitochondria. Oxygen is converted to CO2 in mitochondria. High CO2 levels decrease the oxygen-binding capacity of hemoglobin.
Oxygen is converted to CO2 in mitochondria.
Which of the following statements BEST describes the relationship between photosynthesis and respiration? Photosynthesis only occurs in plants and respiration only occurs in animals. ATP molecules are produced in photosynthesis and used up in respiration. Respiration stores energy in energy-rich, carbon-based molecules, while photosynthesis releases energy from energy-rich, carbon-based molecules. Photosynthesis stores energy in energy-rich, carbon-based molecules, while respiration releases energy from energy-rich, carbon-based molecules. Both photosynthesis and respiration consume more ATP than they produce.
Photosynthesis stores energy in energy-rich, carbon-based molecules, while respiration releases energy from energy-rich, carbon-based molecules.
Which of the following are involved in the initiation of transcription in eukaryotes? Origin of replication, RNA primers, enzymes Promoter, transcription factors, RNA polymerase Telomere, stop codon Start codon, ribosome, mRNA, tRNA Operator, operon, repressor
Promoter, transcription factors, RNA polymerase
Practice exam question. Which statement below about protein hormone synthesis is FALSE? The RNA used for protein hormone synthesis is a copy of the gene for the protein hormone. Protein hormones are synthesized on free ribosomes. The cell invests energy to move protein hormones through the cell. Protein hormones are packaged into vesicles for movement through the cell.
Protein hormones are synthesized on free ribosomes.
Two of the following three functions are fulfilled by the membrane-spanning proteins in biological membranes. Which of the following is NOT one of those functions? Providing passageways for hydrophilic substances that need to be moved into, or out of, the cell. Providing selective and controllable passageways. Providing a rather impenetrable barrier around the cell.
Providing a rather impenetrable barrier around the cell.
Four of the five statements below about amino acids are not correct. Which is correct? The amino acid sequence is the secondary structure of a protein. All amino acids have hydrophilic side chains. Some amino acids have hydrophilic side chains and some have hydrophobic side chains. All amino acids have hydrophobic side chains. No amino acids have a side chain with an electrical charge.
Some amino acids have hydrophilic side chains and some have hydrophobic side chains.
Which of the following are involved in the initiation of translation? Which of the following are involved in the initiation of translation? Origin of replication, RNA primers, enzymes Promoter, transcription factors, RNA polymerase Telomere, stop codon Start codon, ribosome, mRNA, tRNA Operator, operon, repressor
Start codon, ribosome, mRNA, tRNA
In an organism's DNA, what makes one nucleotide different from another? In an organism's DNA, what makes one nucleotide different from another? The sugar The phosphate The base Only some nucleotides have carbon atoms Only some nucleotides have nitrogen atoms
The base
Which of the following is a reasonable explanation for why unsaturated fatty acids help keep a membrane more fluid at lower temperatures? -The double bonds result in shorter fatty acid tails and thinner membranes. -Unsaturated fatty acids permit more water in the middle of the membrane. -Unsaturated fatty acids have a higher cholesterol content and allow more cholesterol in the membrane. -The double bonds form bends or kinks in the fatty acid tails, forcing adjacent (neighboring) lipids and proteins to be further apart. -The double bonds block interactions between the hydrophilic head groups of the lipids.
The double bonds form bends or kinks in the fatty acid tails, forcing adjacent (neighboring) lipids and proteins to be further apart.
Which of the following statements is correct? The light reactions provide the Calvin cycle with oxygen, and the Calvin cycle provides the water for the light reactions. The light reactions provide ATP and NADPH, and the Calvin cycle provides sugar for the light reactions. The light reactions provide the CO2 that is converted to sugar in the Calvin cycle. The light reactions provide ATP and NADPH to the Calvin cycle.
The light reactions provide ATP and NADPH to the Calvin cycle.
Predict what will happen in the membranes of an overwintering plant in Colorado when temperatures rise in the summer. no change The total number of phospholipids in the membranes will decrease. The percentage of saturated phospholipids in the membranes will increase. The percentage of cholesterol molecules in the membranes will increase. The percentage of unsaturated phospholipids in the membranes will increase.
The percentage of saturated phospholipids in the membranes will increase.
Why was Mr. Priestly unable to keep a mouse, sealed in a container together with a plant, alive in his basement? The basement was too hot, which killed the mouse. The plant he used in his experiments in the basement was not edible. The plant did not get the light needed for photosynthesis. The plant in the basement used up all the oxygen it made for photosynthesis.
The plant did not get the light needed for photosynthesis.
Practice exam question. Predict what changes occur in the membranes of a tree growing in South Africas inverted southern-hemisphere climate with cold temperatures in July and hot temperatures in January: The fatty acid composition of the membranes will not change between seasons. The proportion of unsaturated fatty acids will be higher in July than in January. The proportion of unsaturated fatty acids will be lower in July than in January
The proportion of unsaturated fatty acids will be higher in July than in January.
Three of the four answers below explain why a plants green leaves typically have higher rates of photosynthesis compared to respiration. Find the EXCEPTION. -The green leaf is only a small part of the plant and needs to produce enough energy-rich sugars to support all of the non-photosynthetic parts (like roots, non-green stems and trunks, or flowers). -Only when overall photosynthetic activity exceeds overall respiration activity of the whole plant can the plant grow and accumulate biomass. -Sugar produced in photosynthesis supports the energy needs of the plant during the day and the night. -The rate of photosynthesis is higher because leaves dont have mitochondria.
The rate of photosynthesis is higher because leaves dont have mitochondria.
What is the total number of H atoms (white balls) in the saturated (C18:0) fatty acid and the monounsaturated fatty acid (C18:1), respectively, depicted in our lecture PPT. -The saturated fatty acid has 34 H atoms; the monounsaturated fatty acid has 36 H atoms -The saturated fatty acid has 36 H atoms; the monounsaturated fatty acid has 34 H atoms -Both fatty acids have 34 H atoms -Both fatty acids have 36 H atoms
The saturated fatty acid has 36 H atoms; the monounsaturated fatty acid has 34 H atoms
Four of the five features below are shared by lipids, nucleic acids, and proteins. Find the feature NOT shared by all three classes. They are all based on carbon. They are all made from a small number of building blocks. They can all form strings of hundreds of repeating monomer units. Each of their building blocks contains H on one end and OH on the other end. They can all be broken down rather easily by enzyme-catalyzed hydrolysis.
They can all form strings of hundreds of repeating monomer units.
Which of the following is a common feature of all transport proteins found in the outer cell membrane? -They exhibit specificity and allow only a specific type of molecule to pass through. -They have few, if any, hydrophobic amino acids. -They always work against a concentration gradient. -They must be proteins located only on the membrane surface, but not spanning the membrane. -They always require the expenditure of cellular energy in the form of ATP to function.
They exhibit specificity and allow only a specific type of molecule to pass through.
True or False? If you could track carbon atoms, you would find carbon atoms from CO2 as part of sugar and starch molecules in plant leaves and also as a part of sugar and glycogen molecules in animals. True False
True
In facilitated diffusion of ANY substance, what is the role of the transport protein? -Transport proteins organize the phospholipids such as to allow the solute to move directly through the lipid bilayer. -Transport proteins only provide a channel for water molecules to cross the membrane. -Transport proteins provide a site for interaction with ATP, which facilitates the movement of the substance across the membrane. -Transport proteins provide a hydrophilic route for the substance to cross the membrane. -Transport proteins provide the energy for diffusion of the substance.
Transport proteins provide a hydrophilic route for the substance to cross the membrane.
True or false? Insulin produced in a pancreas cell travels through the bloodstream to a target organ where insulin triggers sugar uptake into the target organ. True. False.
True
True or false? Molecules made exclusively from atoms that have an identical or similar attraction for electrons cannot be polar. True False
True
Find the statement that correctly describes the direction of vesicle movement to or from the Golgi apparatus. -Transport vesicles travel from the outer cell membrane to the Golgi apparatus. -Transport vesicles from the rough ER arrive at one side of the Golgi apparatus and leave from the opposite side to travel to the nucleus. -Transport vesicles from the rough ER arrive at one side of the Golgi apparatus and leave from the opposite side to travel to the outer cell membrane. -Transport vesicles travel from the smooth ER to the Golgi apparatus.
Transport vesicles from the rough ER arrive at one side of the Golgi apparatus and leave from the opposite side to travel to the outer cell membrane.
True or false? Substances with a sufficient number of groups with either partial electrical charges or full electrical charges relative to the size of the molecule should dissolve in water. True False
True
A student examines a cell that possesses the following molecules and structures: enzymes, DNA, ribosomes, an outer cell membrane, mitochondria, and chloroplasts. It could be a cell from an animal, but not a plant. a bacterium. a plant or an animal. any kind of organism. a plant, but not an animal.
a plant, but not an animal.
Suppose that a single DNA base change of an "A" to a "T" occurs and is copied during replication. Is this change necessarily a mutation? Suppose that a single DNA base change of an "A" to a "T" occurs and is copied during replication. Is this change necessarily a mutation? Yes, it is a change in the DNA sequence. Yes, if the base change occurs in a gamete (sperm or egg cell); otherwise no. Yes, if the base change occurs in the coding part of a gene; otherwise no. Yes, if the base change occurs in the coding part of a gene and alters the amino acid sequence of a protein; otherwise no. Yes, if the base change alters the appearance of the organism (phenotype); otherwise no.
Yes, it is a change in the DNA sequence.
The structure, and thus the function, of a protein is MOST likely to remain unaffected if a hydrophilic amino acid is replaced by a hydrophobic amino acid. a charged amino acid is replaced by a hydrophilic amino acid. a charged amino acid is replaced by a hydrophobic amino acid. a hydrophobic amino acid is replaced by a charged amino acid. a negatively charged amino acid is replaced by a positively charged amino acid.
a charged amino acid is replaced by a hydrophilic amino acid.
Which of the following fats, each with the same total number of carbon atoms, has the highest energy content? a fat composed of saturated fatty acids a fat composed of monounsaturated fatty acids a fat composed of fatty acids with 2 double bonds each a fat composed of fatty acids with 3 double bonds each
a fat composed of saturated fatty acids
Which of the following is most similar in structure to ATP? a steroid with phosphate groups attached the sodium/potassium pump a phospholipid a triglyceride a nucleotide
a nucleotide
Which of the following has the lowest energy content? a fat consisting of saturated fatty acids with 18 carbon atoms each a phospholipid consisting of saturated fatty acids with 18 carbon atoms each a fat consisting of monounsaturated fatty acids with 18 carbons each
a phospholipid consisting of saturated fatty acids with 18 carbon atoms each
The oxygen consumed during cellular respiration participates most DIRECTLY in what process? phosphorylation of ADP to form ATP glycolysis accepting electrons at the end of the mitochondrial electron transport chain the citric acid cycle forming CO2
accepting electrons at the end of the mitochondrial electron transport chain
The accumulation of high concentrations of charged particles (like H+, K+ or Na+) via transport from low to high concentration occurs only across thylakoid membranes only across inner mitochondrial membranes only across the outer cell membrane across both thylakoid membranes and inner mitochondrial membranes, but not across the cell membrane across thylakoid membranes, inner mitochondrial membranes, and the outer cell membrane
across thylakoid membranes, inner mitochondrial membranes, and the outer cell membrane
Fast-twitch muscle fibers have the advantage of ________ and the disadvantage of _________. extracting a lot of energy from glucose; not acting over extended periods using fat as a long-lasting energy source; not being able to use oxygen acting quickly; not extracting a lot of energy from glucose acting over extended periods; not being able to use fat as an energy source making a lot of ATP; not being able to operate without oxygen
acting quickly; not extracting a lot of energy from glucose
Plants growing in environments that do not allow rapid plant growth typically inactivate the pathway leading to energy storage in the leaves. store little or no starch in their leaves. have low levels of cellulose in their cell walls. activate the pathway leading to energy utilization in the plants growing tissues. activate the pathway leading to energy storage in the leaves.
activate the pathway leading to energy storage in the leaves.
Four of the following processes are energized by phosphorylation (addition of phosphate groups). Find the EXCEPTION. the sodium/potassium pump in the outer cell membrane active H+ transport from low H+ concentration in the matrix to high H+ concentration in the intermembrane space by mitochondrial electron transport transport of vesicles by motor proteins muscle contraction formation of ATP
active H+ transport from low H+ concentration in the matrix to high H+ concentration in the intermembrane space by mitochondrial electron transport
Which of the following functions do RNA molecules perform during translation? Which of the following functions do RNA molecules perform during translation? catalyzing the formation of bonds between amino acids carrying amino acids providing a site for building a protein holding a "message" from the DNA all of these answers
all of these answers
Elongation during transcription directly involves Elongation during transcription directly involves RNA polymerase. complementary base pairing. the synthesis of a nucleic acid. the formation of bonds in a sugar-phosphate backbone. all of these answers.
all of these answers.
During DNA replication During DNA replication each strand can act as a template for the replication of the molecule the two strands of the original DNA molecule must be separated enzymes facilitate all the steps involved each of the original two strands of DNA will wind up in a different chromatid all of these are correct
all of these are correct
In most of your body's cells, the loss of DNA from both ends (telomeres) of chromosomes after many rounds of replication is due to the fact that In most of your body's cells, the loss of DNA from both ends (telomeres) of chromosomes after many rounds of replication is due to the fact that DNA polymerase only synthesizes new strands from 5' to 3'. DNA polymerase can only build onto the end of an existing nucleic acid strand. the two strands of a DNA double helix are antiparallel to one another. enzymes that can rebuild telomeres are not active in most of your cells. all of these are valid reasons.
all of these are valid reasons.
Polar covalent bonds form between atoms with a similar, or the same, degree to which they attract electrons. an intermediate difference in the degree to which they attract electrons. the largest difference in the degree to which they attract electrons.
an intermediate difference in the degree to which they attract electrons.
A cell possesses the following features: enzymes, DNA, ribosome, phospholipid bilayer, energy acquisition and processing. It could be a cell from an animal, but not a plant. a member of the bacteria, but not of the Archaea. a plant or an animal, but no other kind of organism. any kind of organism. a prokaryote but not a eukaryote.
any kind of organism.
Four of the five statements below are correct. Which one is false? Starch and cellulose are both synthesized and found in plants. both contain a lot of energy. are both made of glucose monomers. are both structural components of plant cell walls. are both polysaccharides.
are both structural components of plant cell walls.
Practice exam question. Which is correct? Omega-3 polyunsaturated fatty acids activate genes that stimulate fat storage. are necessary to allow shape changes in the sodium-potassium pump. promote membrane stability at high temperatures. contain more energy than saturated fatty acids with the same number of C atoms have fewer C=C bonds than monounsaturated fatty acids
are necessary to allow shape changes in the sodium-potassium pump.
Hydrophilic molecules are readily soluble in fat. do not mix with water. are water-soluble. can only have polar regions but cannot have a full electrical charge. have no attraction for water molecules.
are water-soluble.
Why do plants use the ATP made by ATP synthase to produce sugars? because animals prefer sugars (due to their sweet taste) over ATP because the ATP made in plant photosynthesis is different from the ATP made in cellular respiration, and only the ATP made in respiration is able to fuel cellular work because ATP is too unstable to store for more than an instant
because ATP is too unstable to store for more than an instant
Lifes large molecules all share the following properties except a complex three-dimensional structure. being quick and easy to assemble. being quick and easy to break down. being based mainly on oxygen. being constructed from small building blocks.
being based mainly on oxygen
Practice exam question. Steroid hormones deliver their message to a target cell by moving across the outer cell membrane of the target cell via facilitated diffusion. binding to a receptor in the nucleus of the target cell. fusion of a vesicle with the outer cell membrane of the target cell. binding to a receptor in the outer cell membrane of the target cell.
binding to a receptor in the nucleus of the target cell.
The burning of natural gas (methane) releases energy because -methane contains tightly held electrons. -carbon dioxide and water contain loosely held electrons. bonds with loosely held electrons are converted to bonds with tightly held electrons. -polar covalent bonds are converted to nonpolar covalent bonds. -C=O and O-H bonds are converted to C-H bonds.
bonds with loosely held electrons are converted to bonds with tightly held electrons.
Four of the five options below finish the sentence in a way that results in a true statement. Find the one that results in a false statement. A fatty acid tail contains lots and lots of C-C bonds C-H bonds bonds with tightly held electrons bonds with loosely held electrons energy
bonds with tightly held electrons
The sodium-potassium pump transports which against its concentration gradient? only Na+ only K+ ATP both Na+ and K+ Na+ and ATP
both Na+ and K+
ATP is produced by mitochondria only. chloroplasts only. transport proteins in the cell membrane. both mitochondria and chloroplasts, but not by transport proteins in the cell membrane. mitochondria, chloroplasts, and transport proteins in the cell membrane.
both mitochondria and chloroplasts, but not by transport proteins in the cell membrane.
Complete the sentence correctly: ATP is produced only by producers. only by consumers. by producers and by consumers. as a convenient storage form of energy in producers. in respiration, but not in photosynthesis.
by producers and by consumers.
All large biological molecules are based on -carbon atoms because carbon readily shares four electron pairs with other carbon atoms, and can thus form large, complex structures. -carbon atoms because C-H bonds are nonpolar. -oxygen atoms because oxygen has a strong attraction for electrons. -oxygen atoms because the O-H bond is polar and thus allows for hydrogen bonds to form that can contribute to the formation of large conglomerates.
carbon atoms because carbon readily shares four electron pairs with other carbon atoms, and can thus form large, complex structures.
Which of the following 5 molecules is MOST STABLE? NADPH ATP NADH sugar carbon dioxide
carbon dioxide
Carbohydrates are formed in the process of photosynthesis from the starting materials of carbon dioxide only. carbon dioxide and water. carbon dioxide and oxygen. water and oxygen.
carbon dioxide and water.
Which cell structure below is correctly matched with its function? rough ER: synthesis of sex hormones ribosomes: lipid synthesis smooth endoplasmic reticulum: protein synthesis Golgi apparatus: information flow from DNA to RNA cell membrane: selective passage of substances
cell membrane: selective passage of substances
Four of the five substances below can serve as fuel for human cellular respiration. Find the EXCEPTION. fats cellulose amylose glucose protein
cellulose
Humans exhale CO2. Which of the four molecules below could NOT be the dietary source of the carbon converted to CO2 and exhaled by you? A carbon atom in a molecule of cellulose starch fructose glucose fat
cellulose
The polysaccharides ________________ occur in plants, while ___________ occur(s) in animals. cellulose and amylopectin; amylose and glycogen glycogen and amylose; cellulose cellulose and amylose; glycogen amylopectin and glycogen; amylose cellulose and glycogen; amylopectin and amylose
cellulose and amylose; glycogen
Which component of animal membranes acts as a temperature buffer, BOTH increasing fluidity at low temperature AND decreasing fluidity at high temperature? phospholipids with monounsaturated fatty acids proteins cholesterol phospholipids with saturated fatty acids phospholipids with polyunsaturated fatty acids
cholesterol
In endothermic animals, the color of their brown fat tissue is due to the presence of many mitochondria. How does brown fat tissue serve the animal? It increases the production of ATP converts most of the energy of food molecules to heat helps the animal stay cool when it is hot increases the usable energy that can be gained from glucose limits the loss of energy as heat
converts most of the energy of food molecules to heat
Where does glycolysis take place? mitochondrial outer membrane mitochondrial inner membrane mitochondrial matrix fluid mitochondrial intermembrane space cytosolic fluid
cytosolic fluid
The polysaccharides used for structural support should be expected to be _______ to break down. difficult easy
difficult
The oxygen released by photosynthesis is a by-product of which specific reaction? conversion of carbon dioxide (CO2) to sugar extraction of electrons from water molecules synthesis of water molecules converting ADP to ATP extraction of electrons from CO2
extraction of electrons from water molecules
True or false? All cells with mitochondria convert the energy of the proton (H+) gradient across the inner membrane into ATP for cellular work. true false
false
Judging from the structure given in our lecture PPT, the molecule of Vitamin A is water-soluble (hydrophilic). fat-soluble (hydrophobic).
fat-soluble (hydrophobic).
Judging from the structure given in our lecture PPT, the molecule of Vitamin D2 is water-soluble (hydrophilic). fat-soluble (hydrophobic).
fat-soluble (hydrophobic).
Judging from the structure given in our lecture PPT, the molecule of Vitamin E overall is water-soluble (hydrophilic). fat-soluble (hydrophobic).
fat-soluble (hydrophobic).
Predict how many molecules of water are needed to COMPLETELY breakdown a polymer consisting of five monomers. two three four five six
four
To which sugar are human taste buds most sensitive? galactose glucose fructose amylose lactose
fructose
A cell that keeps its DNA in a membrane-bounded nucleus could be a cell from which of the following groups of organisms? prokaryotes and protists protists and photosynthetic bacteria bacteria and Archaea fungi and plants bacteria and fungi
fungi and plants
Compare and contrast fats and phospholipids. Three of the four options below are reasons why a phospholipid is better suited for forming biological membranes than a fat. Find the exception. The phospholipid -possesses a phosphate-containing hydrophilic head group instead of a third fatty acid chain. -has a higher energy content than a fat. -has both hydrophobic portions and portions containing electrical charges. -is able to form a bilayer that acts as a barrier for the diffusion of hydrophilic substances.
has a higher energy content than a fat.
Compare and contrast fats and phospholipids. Why is a fat better suited for storage of energy than a phospholipid? The fat possesses a hydrophilic head group instead of a third fatty acid chain. is able to form bilayers. has both hydrophobic portions and portions containing electrical charges. has three fatty acid chains and therefore contains more C-H bonds. has only two fatty acid chains and therefore contains fewer C-H bonds.
has three fatty acid chains and therefore contains more C-H bonds.
Predict: To make a new water-insoluble drug water-soluble (to be easier to take up in your digestive system), a chemist would need to add groups with bonds between atoms that have the same attraction for electrons. have a similar attraction for electrons. have a different attraction for electrons.
have a different attraction for electrons.
Most of the energy captured by producers in an ecosystem is LOST as WHAT in the food chain? ATP heat sunlight sugars starch
heat
Picture a cow eating grass. The majority of the suns energy absorbed by the grass is eventually converted to what form? fat in the cow ATP in the cow glycogen in the cow heat in the environment CO2 in the environment
heat in the environment
DNA replication, transcription, and translation all directly require DNA replication, transcription, and translation all directly require RNA polymerase. hydrogen bonding between complementary nucleotide bases. DNA polymerase. ribosomes. transcription factors.
hydrogen bonding between complementary nucleotide bases.
Fill in the blanks: The polarity of water molecules results in _______ bonds between water molecules, and make a water molecule stick to any molecules with _______ bonds or _________ regions. ionic; polar covalent; charged nonpolar; nonpolar covalent; charged hydrogen; polar covalent; charged hydrogen; nonpolar covalent; charged polar covalent; hydrophilic; hydrophobic
hydrogen; polar covalent; charged
Practice exam question. Predict what the amino acids making up the INTERIOR of the sodium-potassium pump must be like: hydrophobic hydrophilic able to interact with the fatty acid tails of the membrane
hydrophilic
When is a protein needed for movement across membranes? When the moving substance is -hydrophobic and moving either from a lower to higher concentration or moving from a higher to lower concentration. -hydrophilic and moving either from a lower to higher concentration or moving from a higher to lower concentration. -hydrophilic and moving from a lower to higher concentration, but not when moving from a higher to lower concentration. -hydrophobic and only moving from a higher to lower concentration.
hydrophilic and moving either from a lower to higher concentration or moving from a higher to lower concentration.
Synthesis of ATP by the ATP synthase driven by downhill flow of protons (H+) along their concentration gradient takes place only in photosynthesis. only in respiration. in both photosynthesis and respiration, but not during the movement of substances across the outer cell membrane. only during the movement of substances across the outer cell membrane in photosynthesis, respiration, and during the movement of substances across the outer cell membrane.
in both photosynthesis and respiration, but not during the movement of substances across the outer cell membrane.
Where are the proteins of the electron transport chain located in cellular respiration? within the mitochondrial intermembrane space in the mitochondrial inner membranes in the cytosolic fluid in the thylakoid membranes in the mitochondrial matrix fluid
in the mitochondrial inner membranes
Predict where hydrophobic amino acids are found in the sodium-potassium pump: in the binding site for Na+ in the binding site for K+ in the pumps portion in contact with water within the cell in the pumps portion in contact with water outside of the cell in the outer middle regions of the protein in contact with the membranes fatty acid tails
in the outer middle regions of the protein in contact with the membranes fatty acid tails
Where are electron transport chains found in plant cells? only in the cytosol only in the stroma of chloroplasts only in the thylakoid membranes of chloroplasts in the thylakoid membranes of chloroplasts and in the inner membranes of mitochondria in the stroma of chloroplasts and in the matrix of mitochondria
in the thylakoid membranes of chloroplasts and in the inner membranes of mitochondria
The "central dogma" of biology explains how life arose on this planet. the union of sperm and egg creates the next generation. DNA is replicated. new species evolve. information stored in DNA comes to life in two fundamental steps.
information stored in DNA comes to life in two fundamental steps.
Predict which cell contains a lot of rough ER. A cell that is producing insulin any type of hormone estrogen testosterone steroid stress hormones
insulin
Fill in the blank. Na+ and Cl- in table salt are held together by ________ bonds. non-polar covalent ionic polar-covalent hydrogen
ionic
Complete the sentence: The phosphorylation of ADP to ATP does not require energy. is driven by energy from the breakdown of energy-rich sugars. is driven by muscle movement. is driven by the facilitated diffusion of sodium through a sodium channel. is driven by the movement of motor proteins.
is driven by energy from the breakdown of energy-rich sugars.
Predict where a hydrophobic amino acid R group (rest or side group) would be found in a water-soluble protein that transports lipids through the blood stream. -anywhere on the outside of the folded protein chain -lining the pocket within the folded protein chain into which the lipid fits -only in a few locations on the outside of the folded protein chain
lining the pocket within the folded protein chain into which the lipid fits
The following statement compares different starches: Because it is branched and can be broken down to ________ by multiple enzymes at the same time, _________ is digested more quickly than _________. lactose; amylose; amylopectin fructose; cellulose; amylopectin monosaccharides; amylopectin; amylose simple sugars; cellulose; amylose amylopectin; amylose; glycogen
monosaccharides; amylopectin; amylose
Compared to fat, glycogen is mobilized _______ and ________ to become exhausted as an energy source in human metabolism. more slowly; is faster more slowly; is slower more quickly; is faster more quickly; is slower
more quickly; is faster
Prokaryotic and eukaryotic cells share four of the following features. Find the exception. DNA proteins multiple inner compartments outer cell membrane ribosomes
multiple inner compartments
Because starch and cellulose have different functions, they must consist of the same monosaccharide. must both consist of glucose monomers. must have different structures. must consist of different monomers. must occur in different organisms.
must have different structures.
Comparing the photosynthetic light reactions with the Calvin cycle, which CONSUME(S) glucose? both the light reactions and the Calvin cycle neither the light reactions nor the Calvin cycle only the light reactions only the Calvin cycle
neither the light reactions nor the Calvin cycle
A total of three fatty acid chains plus a phosphate-containing hydrophilic head group is found in what? fats phospholipids steroids none of the lipid classes all of the lipid classes
none of the lipid classes
Which of these is rich in unsaturated fats? lard beef fat olive oil butter a fat that is solid at room temperature
olive oil
How many amino acids are responsible for the difference between the more common hemoglobin and sickle-cell hemoglobin? one two three four The exact number is unknown.
one
How many glycerol molecules does a triglyceride contain? none one two three four
one
Of the following fats, each with 18 carbon atoms in each of their fatty acid chains, which has the LOWEST energy content? A fat with -three monounsaturated fatty acids. -one saturated fatty acid plus two polyunsaturated fatty acids, each with 3 C=C bonds. -one polyunsaturated fatty acid with 3 C=C bonds plus two monounsaturated fatty acids. -one monounsaturated fatty acid and two polyunsaturated fatty acids, each with 2 C=C bonds.
one saturated fatty acid plus two polyunsaturated fatty acids, each with 3 C=C bonds.
Consider chemical substances not naturally found in the human body and that act as poisons if they get into one of our cells. Which would be the least likely to be able to get into the cell, and would therefore be the least dangerous? one that is hydrophobic one that is hydrophilic and has a shape unlike any substance normally imported by cells one that is hydrophilic and has a similar shape as a substance normally imported by cells
one that is hydrophilic and has a shape unlike any substance normally imported by cells
From what bonds in a sugar molecule can NO energy be extracted? C-H bonds and C-C bonds C-H bonds and C-OH bonds only C-OH bonds only C-H bonds only C-C bonds
only C-OH bonds
The direct reaction of oxygen (O2) with which of the following releases energy that can be used for ATP formation? -Hydrogen gas (H2), hydrocarbons (as in gasoline), paper (cellulose), electrons (plus H+) at the end of the mitochondrial electron transport chain -only hydrocarbons (as in gasoline), paper (consisting of cellulose), and electrons (plus H+) at the end of the mitochondrial electron transport chain -only paper (consisting of cellulose) and electrons (plus H+) at the end of the mitochondrial electron transport chain -only electrons (plus H+) at the end of the mitochondrial electron transport chain
only electrons (plus H+) at the end of the mitochondrial electron transport chain
Formation of water from oxygen occurs only in photosynthesis. only in respiration. in both photosynthesis and respiration. in neither photosynthesis nor respiration. during the Calvin cycle conversions.
only in respiration.
Where in a plant is ATP synthase (that converts ADP to ATP) located? only on the thylakoid membrane and the inner mitochondrial membrane only on the cell membrane only on the inner mitochondrial membrane on the thylakoid membrane, the cell membrane, and the inner mitochondrial membrane only on the thylakoid membrane
only on the thylakoid membrane and the inner mitochondrial membrane
Comparing the photosynthetic light reactions with the Calvin cycle, which CONSUME(S) ATP? both the light reactions and the Calvin cycle neither the light reactions nor the Calvin cycle only the light reactions only the Calvin cycle
only the Calvin cycle
In DNA replication, the main difference between the "leading strand" and the "lagging strand" is that In DNA replication, the main difference between the "leading strand" and the "lagging strand" is that only the lagging strand is synthesized as a series of short fragments. only the leading strand is made of DNA. only the lagging strand starts with a primer. only the leading strand contains genes. replication of the leading strand is completed before replication of the lagging strand begins.
only the lagging strand is synthesized as a series of short fragments.
Comparing the photosynthetic light reactions with the Calvin cycle, which PRODUCE(S) NADPH? both the light reactions and the Calvin cycle neither the light reactions nor the Calvin cycle only the light reactions only the Calvin cycle
only the light reactions
DNA replication in your cells begins at DNA replication in your cells begins at one end of a chromosome. start codons. origins of replication. stop codons. promoters.
origins of replication.
Prokaryotic cells lack four of the following features. Which feature is found in prokaryotes? mitochondria Golgi apparatus a real nucleus rough endoplasmic reticulum phospholipid bilayers
phospholipid bilayers
Mitochondria are found in all cells. animal cells and bacterial cells, but not in plant cells. animal cells only. plant cells only. plant and animal cells.
plant and animal cells.
The role of the phospholipid bilayer component of the cell membrane is to provide passageways for hydrophilic substances that need to be moved into, or out of, cells. provide selective and controllable passageways. provide a rather impenetrable barrier around the cell.
provide a rather impenetrable barrier around the cell.
Cellulose functions in energy storage in animals. energy storage in plants. providing structural support in plant cell walls. providing structural support in animal cells. providing structural support in plant and animal cell walls.
providing structural support in plant cell walls.
Which of the following RNA molecules catalyzes reactions (i.e., catalyzes the formation of chemical bonds) during translation? Which of the following RNA molecules catalyzes reactions (i.e., catalyzes the formation of chemical bonds) during translation? mRNA pre-mRNA rRNA tRNA none of these.
rRNA
Cellular respiration harvests the MOST chemical energy in which of the following steps? glycolysis alcohol fermentation reactions occurring in the chloroplast stroma reactions occurring in mitochondria lactic acid fermentation
reactions occurring in mitochondria
Fill in the blanks: All of lifes large molecules are synthesized by __________ and broken down by __________. hydrolysis; dehydration removal of a water molecule; addition of a water molecule addition of a water molecule; removal of a water molecule hydrolysis; removal of a water molecule
removal of a water molecule; addition of a water molecule
Which features are found in both animal and plant cells? ribosomes, endoplasmic reticulum, mitochondria, and outer cell membrane mitochondria, chloroplasts, and outer cell membrane ribosomes, mitochondria, and cell walls mitochondria, a large central vacuole, endoplasmic reticulum, and cell walls
ribosomes, endoplasmic reticulum, mitochondria, and outer cell membrane
Of the following, which best describes the sequence of steps for the synthesis and export of proteins by components of the endomembrane system? rough ER →outer cell membrane →vesicle →Golgi Golgi →cell membrane rough ER →vesicle →Golgi →vesicle →ribosome rough ER →vesicle →Golgi →vesicle →cell membrane Golgi →ribosome→ER →vesicle →cell membrane
rough ER →vesicle →Golgi →vesicle →cell membrane
Which cell feature is found in both plant and animal cells? chloroplast cell wall rough endoplasmic reticulum large central vacuole
rough endoplasmic reticulum
Which structure is the site for the synthesis of proteins that will be exported from the cell? rough endoplasmic reticulum free ribosomes smooth endoplasmic reticulum outer cell membrane Golgi apparatus
rough endoplasmic reticulum
Predict which type of fatty acid should be abundant in the membrane phospholipids of microbes living in a hot spring in Yellowstone National Park: saturated unsaturated polyunsaturated
saturated
Predict: In warm climates, plants have relatively more ______________ than ________________ fatty acids in their phospholipids compared to plants from cold climates. unsaturated; saturated cholesterol; saturated cholesterol; unsaturated saturated; unsaturated
saturated; unsaturated
Predict what organisms below would switch out fatty acids of their membrane phospholipids between seasons in response to changes in body temperature? -mammals in tropical regions with rather constant temperatures throughout the year -shellfish in a tropical pond with rather constant temperatures throughout the year -mammals in regions with pronounced temperature changes between the seasons -shellfish in a pond in Sweden with pronounced temperature changes between the seasons
shellfish in a pond in Sweden with pronounced temperature changes between the seasons
Which structure is primarily involved in the synthesis of oils, phospholipids, and steroids? smooth endoplasmic reticulum cell membrane ribosome rough endoplasmic reticulum Golgi apparatus
smooth endoplasmic reticulum
In order to fulfill their function in moving hydrophilic substances from one side of the membrane to the other, transport proteins need to span across the entire membrane. have hydrophobic top and bottom portions. have hydrophobic interior channels. form a layer on the surface of the membrane without spanning the membrane.
span across the entire membrane.
Where do the reactions of the Calvin cycle take place? thylakoid membranes stroma fluid of the chloroplast cytosol fluid surrounding the chloroplast chlorophyll molecule outer membrane of the chloroplast
stroma fluid of the chloroplast
1 glucose + 1 fructose combine to form _______ by ___________. starch; dehydration synthesis sucrose; dehydration synthesis lactose; dehydration synthesis lactose; hydrolysis sucrose; hydrolysis
sucrose; dehydration synthesis
Which of the following dietary carbohydrates should be expected to most strongly activate genes that promote fat storage? all starches cellulose sugars and amylose sugars and amylopectin
sugars and amylopectin
In their FIRST step, the energy of which of the following is used by the chloroplasts light reactions to catapult electrons from low to high potential energy. sugars NADPH CO2 ATP sunlight
sunlight
Three of the four features below serve as DIRECT sources of high-energy electrons for cellular respiration. Which does not? food molecules C-H bonds sugars sunlight
sunlight
The ultimate energy source for producers is ________ and the final energy-rich product produced in the mitochondria of consumers is ________. water; ATP sunlight; ATP CO2; sugar sugar; sugar sunlight; sugar
sunlight; ATP
The glucose made in photosynthesis is used by the plant in three of the following processes. Find the exception. cellulose synthesis synthesis of starch as an energy store to fuel the plants cellular respiration synthesis of glycogen as an energy store
synthesis of glycogen as an energy store
In response to consumption of high levels of saturated fats and sugars, humans and other mammals will synthesize more of the enzymes needed for cellular respiration store less energy as fat eat less synthesize more of the enzymes needed for energy storage synthesize fewer of the enzymes needed for energy storage
synthesize more of the enzymes needed for energy storage
Two species that harbor microbes capable of breaking down cellulose for energy are humans and cats. humans and termites. termites and cows. cows and cats. termites and cats.
termites and cows.
An example for a nonpolar covalent bond is the C-H bond. the O-H bond. the C=O bond. the bond between Na+ and Cl-. the bond that forms between two different water molecules.
the C-H bond.
Four of the five reactions below occur in the cytosol. Which does not? alcohol fermentation glycolysis use of ATP for mechanical work the Calvin cycle lactic acid fermentation
the Calvin cycle
The energy released by electrons flowing through the mitochondrial electron transport chain is DIRECTLY captured to energize glucose formation the build-up of a proton gradient ATP formation H2O formation NADH formation
the build-up of a proton gradient
The energy for facilitated diffusion comes from the transport protein. the transported substance. ATP. the concentration gradient (gradient in potential energy) of the transported substance.
the concentration gradient (gradient in potential energy) of the transported substance.
What provides the energy for the uphill transport of Na+ against its concentration gradient? No energy is needed. the unphosphorylated Na+/K+ pump the K+ ions the energy-rich ATP the potential energy contained in the Na+ concentration gradient
the energy-rich ATP
All of the processes below are somehow related to ATP production in mitochondria. Which process directly turns the ATP synthase turbine in mitochondria: -the flow of H+ along its concentration gradient from the intermembrane space to the matrix. -the transfer of electrons to oxygen as the terminal electron acceptor. -the loading of electrons from NADH into the mitochondrial electron transport chain. -the removal of H (electrons and H+) from C-H bonds of energy-rich food molecules in glycolysis. -the removal of H (electrons and H+) from C-H bonds of energy-rich food molecules in the citric acid cycle.
the flow of H+ along its concentration gradient from the intermembrane space to the matrix.
Ionic bonds form between atoms with the same degree to which they attract electrons. a similar degree to which they attract electrons. an intermediate difference in the degree to which they attract electrons. the largest difference in the degree to which they attract electrons.
the largest difference in the degree to which they attract electrons.
Which of the following is defined as mechanical work? the movement of muscle proteins. the movement of calcium along its concentration gradient. the movement of sodium out of the cell and of potassium into the cell. the synthesis of large molecules. the movement of water through an aquaporin protein via osmosis.
the movement of muscle proteins.
Which of the following is defined as transport work? the movement of muscle proteins. the movement of calcium along its concentration gradient. the movement of sodium out of the cell and of potassium into the cell. the synthesis of large molecules. the movement of water through an aquaporin protein via osmosis.
the movement of sodium out of the cell and of potassium into the cell.
From the fact that high fructose corn syrup (HFCS) tastes sweeter than regular table sugar, one can conclude that -HFCS contains fructose, but table sugar does not. -glucose and fructose must both be monosaccharides. -the percentage of fructose in HFCS must be higher than that in table sugar. -the percentage of fructose in HFCS must be 55%. -fructose must stimulate the production of hormones that control blood sugar level.
the percentage of fructose in HFCS must be higher than that in table sugar.
Fill in the blanks: In the model of the hydroelectric dam, water stands for ________, the turbine stands for ________, and the lit-up light bulb stands for _________. the ATP synthase; the protons (H+); the ATP produced the protons (H+); the ATP produced; the ATP synthase the protons (H+); the ATP synthase; the ATP produced the ATP produced; the protons (H+); the ATP synthase
the protons (H+); the ATP synthase; the ATP produced
Each strand of a DNA molecule can act as a template for DNA replication because Each strand of a DNA molecule can act as a template for DNA replication because the rules of complementary base pairing dictate exactly what the sequence of nucleotides in a newly synthesized strand should be. your entire genome sequence is stored in your brain, and your brain tells each copy of the DNA polymerase enzyme what to do. the two strands of a DNA molecule are exactly the same. the two chromosomes in a homologous pair are identical to each other. genes that are read during transcription may be found in either strand of the DNA molecule.
the rules of complementary base pairing dictate exactly what the sequence of nucleotides in a newly synthesized strand should be.
In mitochondria, protons are moved by the mitochondrial electron transport chain against their concentration gradient from the matrix into the intermembrane space, whereas in chloroplasts, protons are moved by the photosynthetic electron transport chain against their concentration gradient from the stroma to the cytosol. the intermembrane space to the matrix. the matrix to the stroma. the stroma to the inner thylakoid space. the inner thylakoid space to the stroma.
the stroma to the inner thylakoid space.
Which of following is defined as chemical work? the movement of muscle proteins. the movement of calcium along its concentration gradient. the movement of sodium out of the cell and of potassium into the cell. the synthesis of large molecules. the movement of water through an aquaporin protein via osmosis.
the synthesis of large molecules.
H2O is converted to O2 in__________, while O2 is converted to H2O in ___________. the mitochondrion; the chloroplast the thylakoid membranes; the inner mitochondrial membranes the chloroplast stroma; the mitochondrial matrix the inner mitochondrial membranes; the thylakoid membranes the thylakoid membranes; the chloroplast stroma
the thylakoid membranes; the inner mitochondrial membranes
The light reactions of photosynthesis occur in the stroma fluid thylakoid membranes cytosol fluid mitochondria chloroplast fluid space
thylakoid membranes
In a polar covalent bond, the electrons are -completely transferred from one atom to the other. -loosely held between the two atoms forming the bond. -tightly held by one of the atoms forming the bond. -equally attracted by both atoms forming the bond. -equally shared between the two atoms forming the bond.
tightly held by one of the atoms forming the bond.
Carbon dioxide containing bonds with ________ held electrons is converted to sugar molecules containing bonds with ______ held electrons in the Calvin cycle. loosely; tightly loosely; loosely tightly; loosely tightly; tightly
tightly; loosely
What is the primary function of the Calvin cycle? to use NADPH to release carbon dioxide to synthesize starch from carbon dioxide to extract electrons from water and release oxygen to synthesize a simple sugar (G3P) from carbon dioxide to use ATP and NADPH to convert a simple sugar (G3P) to carbon dioxide
to synthesize a simple sugar (G3P) from carbon dioxide
ALL of the energy is released as HEAT when protons (H+) flow downhill through the ATP synthase in mitochondria. ATP synthase in chloroplasts. uncoupling protein in mitochondria. photosynthetic electron transport chain. mitochondrial electron transport chain.
uncoupling protein in mitochondria.
Predict which type of fatty acid should be abundant in the membrane phospholipids of microbes living in a glacier in Rocky Mountain National Park: saturated unsaturated
unsaturated
Four of the five features below present a state of high chemical potential energy in photosynthesis. Find the exception. glucose excited electrons NADPH ATP water
water
Water is able to pass very quickly through cell membranes because the phospholipid bilayer is hydrophilic. water moves through hydrophobic channels. water is a small, polar, uncharged molecule. water moves through aquaporin proteins in the membrane. water movement is tied to the expenditure of cellular energy in the form of one ATP for each water molecule.
water moves through aquaporin proteins in the membrane.
Judging from the structure given in our lecture PPT, the molecule of Vitamin C is water-soluble (hydrophilic). fat-soluble (hydrophobic).
water-soluble (hydrophilic).
Lactose tolerance is highest in human populations with no history of dairy farming. with a long history of dairy farming over many generations. with a history of dairy farming that began one generation ago.
with a long history of dairy farming over many generations.
Predict with which partner an oxygen atom (O) will most likely form a nonpolar covalent bond. -with a hydrogen (H) atom -with a carbon (C) atom -with another oxygen (O) atom -with an atom that attracts electrons more strongly (is more electronegative) than O -with an atom that attracts electrons less strongly (is less electronegative) than O
with another oxygen (O) atom
Predict where a hydrophilic amino acid R group (rest or side group) would be found in a membrane channel facilitating the movement of hydrophilic fructose across a biological membrane. only in the top, but not the bottom, portions of the channel, in contact with aqueous fluid within the internal channel formed by the folded protein chain on the outer middle part of the membrane channel, in contact with the membrane core
within the internal channel formed by the folded protein chain