biology unit 3 bellringers

Albumin is a large protein which circulates freely in human plasma. Another type of protein, called aquaporins, act as a channel for water to enter and exit a cell, and are located within the lipid bilayer of a cell's plasma membrane. Based on their physiological locations, how would the tertiary structure of these two proteins mostly likely compare? a. Albumin has a more polar core with a polar outer layer, while aquaporins have a more nonpolar core with a nonpolar outer layer b. Albumin has a more polar core with a nonpolar outer layer, while aquaporins have a more nonpolar core with a polar outer layer c. Albumin has a more nonpolar core with a nonpolar outer layer, while aquaporins have a more polar core with a polar outer layer d. Albumin has a more nonpolar core with a polar outer layer, while aquaporins have a more polar core with a nonpolar outer layer

d

Base your answer on the graph and on your knowledge of biology. Which is a true statement about the relationship between pH and enzyme action? a. All enzymes work best at a neutral pH. b. Adding more acid does not affect the rate of activity of an enzyme. c. Enzymes function only in a pH range of 4.0 to 5.5. d. The activity of an enzyme is affected by pH.

d

A macromolecule is composed of smaller units called a. monomers b. polymers c. cells d. isotopes

a

Class of carbohydrate which cannot be hydrolyzed further, is known as? a. monosaccharides b. disaccharides c. polysaccharides d. oligosaccharides

a

Polypeptides are chains of amino acids linked together in a specific order? What type of bonds are formed between these amino acids? Choose 1 answer: a. peptide bonds b. glycosidic linkages c. hydrogen bonds d. ester linkage

a

Researchers studied the activity of mevalonate kinase, an enzyme that may be important for biofuel production. The graph below shows the rate of a reaction as the concentration of ATP is increased while substrate concentration remains constant. The open circles represent data points collected at 30oC and the closed circles represent data points collected at 37oC. How is the reaction between enzyme and substrate modified by the different temperatures? a. At 30oC, the substrate molecules have less kinetic energy than at 37oC. This reduces the rate of random collisions and therefore the rate of the reaction. b. AT 30oC, the substrate molecules have more kinetic energy than at 37oC. The excess kinetic energy makes it harder for the substrate to bind to the enzyme. c. At 37oC, the enzymes have formed the correct shape to maximize the reaction rate. At 30oC, the enzymes have denatured due to excess heat and the substrates have more difficulty binding to the active site. d. At 37oC, the concentration of the substrates is higher than at 30oC. This allows the reaction to proceed more rapidly.

a

The main elements used in carbohydrates and lipids are: a. C, H, and O b. S, C, O, and O c. Na, Cl, S, and H d. N, P, and H

a

The major protein component of human hair is α-keratin. Hair 'straighteners' are commonly used tools which use heat to iron hair into temporarily lying flat and straight. What is the best biological explanation for this phenomenon? a. Hair straighteners disrupt hydrogen bonds in α-keratin b. Hair straighteners disrupt ionic bonds between α-keratin molecules c. Hair straighteners disrupt disulfide bridges in α-keratin d. Hair straighteners denature proteins by disrupting the pH

a

Which of the following are function of proteins? Choose two (2) answers: a. cell signaling b. energy storage c. encoding genetic information d. catalyzing chemical reactions

a d

A certain genetic disorder prevents the production of signalling molecules which direct the intracellular trafficking of proteins. If the disease exclusively affects the signal which directs proteins to the proteasome, what primary effect would most likely be observed? Proteasome = a protein complex in cells containing proteases; it breaks down proteins that have been tagged by ubiquitin. Protease = an enzyme that catalyzes the breakdown of proteins into smaller polypeptides or single amino acids. Ubiquitin = small regulatory protein that directs the movement of important proteins in the cell. a. increased synthesis of proteins b. decreased degradation of proteins c. increased degradation of proteins d. decreased synthesis of proteins

b

A process that occurs in the human body is shown in the diagram. What would happen if a temperature change caused the shape of the active site to be altered? a. The dipeptide would digest faster. b. The dipeptide would digest slower or not at all. c. The amino acids would combine faster. d. The amino acids would combine slower or not at all.

b

Albumin is a protein that is found in eggs. Which of the following describes the structure of albumin? Choose 1 answer: a. A molecule containing carbon, hydrogen, and oxygen in a 1:2:1 ratio. b. A chain of amino acids folded and twisted into a molecule. c. Three fatty acids to one glycerol molecule. d. A series of nitrogenous bases attached to a sugar-phosphate backbone.

b

Based on the information in the graph, choose the statement that best describes the reaction it depicts. a. The reaction absorbs energy. b. The reaction releases energy. c. The reaction fails to proceed because of insufficient energy. d. The reaction fails to proceed because it does not involve an energy change

b

Carbohydrates, lipids, proteins, and nucleic acids are organic molecules essential for life. Which of the following elements makes the large structures of these organic molecules possible? a. calcium b. carbon c. oxygen d. zinc

b

Fat is a constituent of each of the following. Which one has a significant amount of unsaturated fat? a. chicken b. tuna c. lamb d. beef

b

Identify the following chemical reaction: a. catabolic reaction b. dehydration synthesis reaction c. hydrolysis reaction d. exothermic reaction

b

In what way could you increase the rate of the reaction as taking place in image C? a. add more substrate b. add more enzyme c. remove enzymes d. remove substrate

b

Monkeys and humans share many of the same DNA sequences and have similar proteins, indicating that a. the two groups belong to the same species. b. the two groups share a relatively recent common ancestor. c. humans evolved from monkeys. d. monkeys evolved from humans. e. the two groups first appeared on Earth at about the same time.

b

The diagram shows a metabolic pathway What would happen to the rate of production of D if enzyme 1 was not present? a. it would be reduced b. it would stop c. it wouldn't be any different d. it would be increased

b

What does the word organic mean? a. has nitrogen b. has carbon c. has sulfur d. has oxygen

b

What happens when a protein denatures? a. Its primary structure is disrupted. b. Its secondary and tertiary structures are disrupted. c. It becomes irreversibly insoluble and precipitates. d. It hydrolyzes into component amino acids. e. Its hydrogen bonds, ionic bonds, disulfide bridges, and peptide bonds are disrupted.

b

Which of the following are roles of amino acids at an enzyme's active site? Choose 1 answer: a. Converting the enzyme to receive a different substrate. b. Binding the substrate to the enzyme c. Preventing the substrate from entering the chemical reaction. d. Changing the enzyme itself.

b

Which one of the following groups of chemicals is not a food nutrient? a. proteins b. enzymes c. carbohydrates d. vitamins

b

Which one of the following provides the greatest energy value per gram of nutrient: a. carbohydrate b. fat c. protein d. water

b

Which statement is true of enzymes? Choose 1 answer: a. Changes in temperature do not affect enzymes. b. The activity of an enzyme might change as pH changes. c. Enzymes work independently of substrate concentration. d. Enzymes are non-specific.

b

Without the presence of enzymes, the reactions necessary to sustain life would require ____ in order to occur. a. larger cells b. higher temperature c. larger proteins d. smaller atoms

b

dehydration synthesis= ______________ and ________________ water

breaking down and removing water

A new drug is developed which selectively cleaves covalent bonds between two sulfur atoms of non-adjacent amino acids in a polypeptide chain. Which level of protein structure in affected molecules would be most directly affected by the drug? a. Primary structure b. Secondary structure c. Tertiary structure d. Quaternary structure

c

For a person who had received medical advice to cut down animal fats, which of the following protein foods would you recommend? a. pork b. salmon c. chicken d. minced beef

c

Name the major storage form of carbohydrates in animals? a. cellulose b. chitin c. glycogen d. starch

c

Students digging near their school unearthed four objects. One of the objects was part of the exoskeleton of an insect. The table shows the results of a chemical analysis of the objects. W: chlorine, sodium X: oxygen silicon Y: carbon, hydrogen, nitrogen, oxygen Z: aluminum, silicon, oxygen, hydrogen Based on the chemical analysis, which object is most likely from the exoskeleton? a. Object W b. Object X c. Object Y d. Object Z

c

The diagram shows the structure of starch, a complex carbohydrate. What best describes the relationship between starch and glucose? a. Starch and glucose are reactants that combine to form proteins. b. Starch is a monomer that is used to make glucose. c. Starch is a polymer made of glucose monomers. d. Starch and glucose are reactants that combine to form nucleic acids.

c

The graph below shows the percent of mass of six common elements in the human body. *most amounts of elements* What are elements 5 and 6? a. zinc and sulfur b. sodium and iron c. carbon and oxygen d. chlorine and phosphorus

c

What is the best description of this molecule? a. chitin b. amino acid c. polypeptide (tripeptide) d. nucleotide e. protein

c

Which of the following is an example of protein denaturation? a. Several amino acids are joined together via peptide bonds. b. A protein binds with a substrate, lowering the activation energy of a reaction. c. A protein is exposed to extremely high heat, causing it to lose its secondary structure and be left with only its primary structure. d. Amino acids fold into repeating patterns due to hydrogen bonding of the peptide backbone.

c

Which of the following protein structures is most likely to act like a strong fiber in the body? a. DNA polymerase b. Enzyme c. Collagen d. Casein

c

Which part of the amino acid gives it uniqueness? a. amino group b. carboxyl group c. side chain (R group) d. None of the mentioned

c

Creutzfeldt-Jakob Disease (CJD) is a degenerative neurological disorder. Biopsy of the the brains of affected individuals reveals aggregations of a "prion protein"―a protein which is capable of folding into multiple, structurally distinct forms. In CJD, two versions of the offending protein have been identified. The normal form is predominantly composed of alpha helix, while the variant has significant beta structure. The beta structure presumably has more solvent accessible hydrophobic groups, lacking a polar outer layer. Knowing only this, how might you differentiate between the normal and variant conformations given a sample of each in the lab? a. Determine the polypeptide sequence of each sample and compare them to a known database b. Determine the mass of the crystallized structure of a single c. Denature each sample with heat, and analyze the polypeptide chains by NMR d. Attempt to dissolve both samples in water, knowing that if it dissolves it is the normal protein

d

How does an enzyme affect the rate of a reaction? Choose 1 answer: a. It lowers the activation energy of the reaction, decreasing the reaction rate. b. It raises the activation energy of the reaction, increasing the reaction rate. c. It raises the activation energy of the reaction, decreasing the reaction rate. d. It lowers the activation energy of the reaction, increasing the reaction rate.

d

The enzyme ptyalin helps digest carbohydrates, while the enzyme pepsin helps digest proteins. What prevents ptyalin and pepsin from digesting the same type of food? Choose 1 answer: a. One is a protein and the other is a carbonhydrate. b. They require a different number of molecules to react. c. They have the same amino acids chain. d. They have different shapes.

d

The table below show three enzymes found in human body, and the temperature of their locations. How would a fever of 104oF (too high) most likely affect the activity of these enzymes? Choose 1 answer: a. It would cause the enzyme to adapt to the new temperature. b. It would increase enzyme activity to fight the infection off faster. c. It will change the genetic code of the enzyme. d. It could slow or stop enzyme function.

d

Unlike saturated fatty acids, unsaturated fatty acids: are found mostly in animal fats and oils a. contain hydrogen, carbon, nitrogen, and oxygen b. are often covalently bonded to sugars c. lack of carboxyl group d. contain double covalent bonds between carbons in their hydrocarbon chain

d

Which of the following best explains why an increase in reactant concentration generally increases the rate of a chemical reaction? Choose 1 answer: a. The average speed of the reactant particles is increased. b. The rate constant of the reaction is increased. c. The activation energy barrier of the reaction is decreased. d. The collision rate between reactant particles is increased.

d

Most reactions are more rapid at high temperatures than at low temperatures. This is consistent with: (I) an increase in the activation energy with increasing temperature. (II) an increase in the rate constant wit increasing temperatures. (III) an increase in the percentage of "high energy" collisions with increasing temperatures. a. only I b. only II c. only III d. only I and II e. only II and III

e

Which of the following is not one of the many functions performed by proteins? a. signals and receptors b. enzymatic catalyst for metabolic reactions c. protection against disease d. contractile components of muscle e. storage of triglycerides in the liver

e