Week 1 Flashcards
Which of the following is a prokaryotic domain?
a) The domain Bacteria and the domain Archaea
b) Eukarya
c) Protists
d) Fungi
e) Archaea only
Bacteria and Archaea
How many natural occurring elements are there?
94
What are four of the most abundant elements found in living organism?
Hydrogen, Carbon, Oxygen and Nitrogen
- Which of the following is a trace element?
a) Copper
b) Nitrogen
c) Hydrogen
d) Carbon
e) oxygen
A) copper
- Which of the following molecules has the shape of a completed tetrahedron?
a) Glucose (C6H12O6)
b) Hydrogen gas (H2)
c) Water (H2O)
d) Oxygen gas (O2)
e) methane (CH4)
e) CH4 Methane
Hydrophilic substances, but not hydrophobic substances,_________ .
a) accept electrons from solvents
b) give up electrons to solvents
c)have charges or partial charges to which water molecules can adhere
d) have a higher bond energy than water
are
have charges or partial charges to which water molecules adhere
Adhesion is best described as _________.
a) the property that contributes to the transport of water and dissolved nutrients in plants by causing water molecules to tug on other water molecules
b) none of the listed responses is correct.
c) a property of water that helps moderate Earth’s temperature
d) the clinging of one substance to another substance
e) the process by which a crystalline lattice forms
(b) the clinging of one substance to another
Ionic bonds form as a result of_________ .
a) chance accumulations of electrons as they move around atomic nuclei
b) attraction between hydrogen and other atoms that share electrons unequally
c) sharing of electron pairs between atoms
d) unequal sharing of electrons between atoms
e) attraction between ions that have opposite charges
e) attraction between ions that have opposite charges
Coastal climates are more moderate than inland climates primarily because of water’s high __________.
a) heat of vaporization
b) density
c) specific heat
d) heat of fusion
e) surface
C) specific heat
How many electrons would be present in the valence shell of a sulfur atom (atomic number 16, mass number 32)?
a) Four electrons
b) Eight electrons
c) Two electrons
d) Six electrons
e) One electron
d) six electrons
When the number of protons and electrons possessed by an atom are unequal, the atom __________.
a) is an ion
b) forms a covalent bond with another atom
c) becomes part of a molecule
d) gains or loses a proton
a) is an ion
- Which of the following has negligible mass?
a) Electron
b) Element
c) Neutron
d) Atom
e) Proton
a) electron
Isotopes of an element will always differ in__________.
a) atomic number
b) symbol
c) atomic mass
d) number of proton
c) atomic mass
- An atom that normally has ______ in its outer shell would not form chemical bonds with other atoms.
a) one electron
b) six electrons
c) three electrons
d) eight electrons
d) eight electrons
Sweating has a cooling effect because of water’s high________.
a) buffering capacity
b) surface tension
c) heat of vaporization
d) specific heat
c) heat of vaporization
- Cells are surrounded by water, and cells themselves consist of about 70 to 95 percent water. As a result,____________.
a) all of the listed responses are correct
b) a variety of nutrient molecules is readily available as dissolved solutes
c) waste products produced by cell metabolism can be easily removed
d) dissolved substances can be easily transported within a cell or between cells in multicellular organisms
e) the temperature of living things tends to change slowly
a) all of the above
The number of protons in an uncharged atom_________ .
a) equals the number of neutrons
b) equals the number of electrons
c) equals the number of electrons in the outer orbital of the atom
d) varies with the different isotopes
determines its mass number
b) equals the number of electrons
- A covalent bond will be polar if
_______.
a) one of the atoms sharing electrons is more electronegative
b) the two atoms sharing electrons are equally electronegative
c) it is between two atoms that are both very strong electron donors
d) the two atoms sharing electrons are of the same element
e) the atoms sharing electrons are both highly electronegative
a) one of the atoms sharing is more electronegative
- The tendency of water molecules to stay close to each other as a result of hydrogen bonding __________.
a) All of the listed responses are correct.
b) acts to moderate temperature
c) is called cohesion
d) keeps water moving through the vessels in a tree trunk
a) all of the listed responses are correct
- The chemical characteristics or reactivity of an element depend mostly on the___________.
a) mean energy level of its electrons
b) number of electrons in its outermost shell
c) degree to which it has more or fewer electrons than protons
d) number of electron shells
b) number of electrons in its outermost shell
You can fill a glass of water to just slightly above the rim without it spilling over. What property of water best explains this phenomenon?
a) Surface tension
b) Heat of vaporization
c) Adhesion
d) Evaporative cooling
A) surface tension
- Which of the following functional groups increases the solubility of organic compounds in water?
a) -OPO32-
b) -NH2
c) All of the listed responses are correct.
d) -COOH
e) -OH
c) all the listed responses are correct
- Emergent properties of living systems are defined as properties that ________.
a) None of the listed responses is correct.
b) are evident during only one portion of the life cycle of an organism
c) are due to the arrangement and interactions of parts as complexity increases
d) define the cell’s surroundings
e) are apparent only when an organisms is studied at a molecular level
c) are due to the arrangement and interactions of arts as complexity increases
Which of the following hydrocarbons has a double bond in its carbon skeleton?
a) C2H6
b) CH4
c) C2H4
d) C2H2
e) C3H8
c) C2H4
- Manufacturers make vegetable oils solid or semisolid at room temperature by________ .
a) adding hydrogen atoms to the single bonds of the fatty acid hydrocarbon chains
b) removing hydrogen atoms and forming additional single bonds in the fatty acid hydrocarbon chains
c) removing hydrogen atoms and forming additional double bonds in the fatty acid hydrocarbon chains
d)None of the listed responses is correct.
e) by adding hydrogen atoms to the fatty acid hydrocarbon chains
e) by adding hydrogen atoms to the fatty acid hydrocarbon chains
- Which of the following components of a tossed salad will pass through the human digestive tract and be digested the least?
a) Starch (in the croutons)
b) Sugar (in the dressing)
c) Oil (in the dressing)
d) Protein (in the bacon bits)
e) Cellulose( in the lettuce)
e) Cellulose ( in the lettuce)
Cellulose is a_________made of many__________.
a) polymer; glucose molecules
b) protein; amino acids
c) polypeptide; monomers
d) lipid; triacylglycerols
e) carbohydrate; fatty acids
a) polymer; glucose molecules
In what polysaccharide form do plants store glucose to be available later as an energy source?
a) Starch
b) Protein
c) Fatty acids
d) Cellulose
e) Glycogen
a) starch
Amylase is an enzyme that breaks down starch. Why can’t the same enzyme break down cellulose?
a) The enzyme cannot attack cellulose because of its helical shape.
b) Starch is made of glucose; cellulose is made of fructose.
c) The bonds between the monosaccharide monomers in cellulose are between oxygen atoms.
d) The monosaccharide monomers in cellulose are bonded in a different orientation than in starch.
e) Cellulose molecules are much too large.
d) the monosaccharides in cellulose are bonded in a different orientation than starch
The lipids that form the main structural component of cell membranes are_________ .
a) cholesterol
b) proteins
c) carbohydrates
d) triacylglycerols
e) phospholipids
e) phospholipids
What is the appropriate term for a group of all the individuals that can mate with each other living within a specified area?
a) Community
b) Species
c) Habitat
d) Ecosystem
e) Population
e) population
Some lipids are formed when fatty acids are linked to glycerol. These subunits are linked together by___________.
a) peptide bonds
b) ester linkages
c) phosphodiester linkages
d) ionic bonds
e) glycosidic linkage
b) ester linkages
Which of the following are properties of hydrocarbons?
a) Hydrophobic, containing numerous amine groups, and polar
b) Hydrophilic, a good source of stored energy, and consisting primarily of carbon and hydrogen
c) Hydrophobic, nonpolar, and a good source of stored energy
d) Hydrophilic, containing numerous carboxyl groups, and nonpolar
e) Hydrophobic, polar, and charged
c) hydrophobic, non polar, and a good source to stored energy
The sex hormones estrogen and testosterone belong to which class of molecules?
a) Amino acids
b) Proteins
c) Nucleic acids
d) Lipids
e) Carbohydrates
d) lipids
Which of the following is a polymer?
a) Triacylglycerol, or fat
b) Cellulose, a plant cell wall component
c) Fructose, a component of sucrose
d) Glucose, an energy-rich molecule
e) testosterone’s steroid hormone
b) cellulose, a plant cell wall component
Eukaryotic organisms that decompose dead organisms and absorb dissolved nutrients from their surroundings would be found in which kingdom?
a) Animalia
b) Bacteria
c) Fungi
d) Archaea
e) Plantae
c) Fungi
Energy _______ an ecosystem, whereas chemical elements__________.
a) is recycled in; flow through it
b) is burned in; are wasted
c) cannot be created nor destroyed in; disappear
d) flows through; cycle within it
d) flows through; cycle within it
Which of the following is the fundamental unit of structure and function in living organisms?
a) Organ
b) Cell
c) Organelle
d) Tissue
e) Organism
B) cell
All of existing bacteria is bad for human body.
True
False
FALSE
All the organisms on your campus make up__________.
a) a domain
b) an experimental group
c) a population
d) a community
e) an ecosystem
d) community
Capillary action involves the following THREE properties of water: adhesion, ________________, and surface tension.
a) None of the listed choices is correct
b) non-polarity
c) polarity
d) cohesion
d) cohesion
The first falling leaf of the season has tumbled from the air and landed on the top of the pond. It does not sink, but yet float on top of the surface. What is happening on a molecular level that is preventing the leaf from sinking?
a) Both oxygen and hydrogen are positively charged and therefore much stronger
b) Both c and d
c) The surface area of the leaf is quite large and is breaking the hydrogen bonds of the water molecules on the surface
d) The covalent bonds between the oxygen and hydrogen atoms are not breaking apart due to the lack of weight placed upon them
e) There is not enough weight to break the hydrogen bonds between water molecules at the surface of the water
e) There is not enough weight to break the hydrogen bonds between water molecules at the surface of the water
The organisms depicted above (mushrooms) belong to the following group
a) Animalia
b) Eukaryotes
c) Protists
d) Prokaryotes
b) Eukaryotes
Water molecules bond in a crystalline form as the temperature of water drops. This creates more space between water molecules. What characteristic of water does this change describe?
a) surface tension
b) density
c) polarity
d) adhesion
e) specific heat
b) density
What is meant by the fact that water is a “polar” molecule?
a) Water has a slightly negative charge overall
b) Water has no evident charge, unless in sold form
c) Water has a very evident charge, but only in a gaseous form
d) None of the above
e) Water has a slightly positive charge, but only as a liquid
d) None of the above
What is the primary source of energy that makes life on Earth possible?
a) Decomposition of plants and other organic matter
b) Carbon dioxide
c)Sugars
d) Heat
e) The Sun
e) the sun
Which of the following sequences correctly lists life’s hierarchy of levels of organization from lowest to highest?
a) Organ, tissue, organ system, organism, population
b) Molecule, biosphere, cell, organ, organism
c) Organism, community, population, ecosystem, biosphere
d) Tissue, cell, organ, organism, community
e) Molecule, organelle, cell, tissue, organ, organism
e) Molecule, organelle, cell, tissue, organ, organism
Which polysaccharide has the greatest number of branches?
A. cellulose
B. chitin
C. amylose
D. amylopectin
E. glycogen
e. glycogen
Jack is studying biological molecules and their properties. The molecule he is focusing on is the one that is hydrophobic. What functional group would you expect to find on this molecule?
a) A sulfhydryl group (-SH)
b) A hydroxyl group (-OH)
c) A methyl group (-CH3)
d) A carboxyl group (-COOH)
e) None of the listed responses is correct
c) a methyl group (-CH3)
Which best describes how hydrogen bonds are created?
a) The negative charge of an oxygen binds with the positive charge of a hydrogen on an adjacent molecule
b) The positive charge of an oxygen binds with the negative charge of a hydrogen on an adjacent molecule
c) The negative charge of an oxygen binds with the positive charge of a hydrogen within the SAME molecule
d) The negative charge of an oxygen binds with the positive charge of a hydrogen within the SAME molecule
a) The negative charge of an oxygen binds with the positive charge of a hydrogen on an adjacent molecule
High cholesterol levels are considered a major risk factor for heart disease. If it is so bad for humans, why does the body make cholesterol in the first place?
a) Cholesterol aids in the formation of amino acids that are used to build proteins.
b) Cholesterol is not important for humans anymore. It is a holdover from hunter-gatherer days when food was scarce.
c) Cholesterol is an important constituent of nucleotides.
d) Cholesterol is the basis for many important molecules such as sex hormones
e) Cholesterol is an important energy storage molecule
d) Cholesterol is the basis for many important molecules such as sex hormones
A triglyceride is made up of
a) 3 fatty acids joined to 1 glycerol by ester linkage
b) 3 fatty acids joined to 1 glycerol by phosphodiether linkage
c) 1 fatty acid joined to 3 glycerol by ester linkage
d) 2 fatty acids and 1 phosphate joined to 1 glycerol by ester linkage
a) 3 fatty acids joined to 1 glycerol by ester linkage
What is the role of van der Waals interactions in biological molecules?
a) Van der Waals interactions are strong bonds that play a major structural role in holding proteins together.
b) Van der Waals interactions are only important in water.
c) Although they are weak bonds, van der Waals interactions involve the sharing of electrons.
d) Although they are weak bonds, van der Waals interactions help to reinforce the three-dimensional shapes of large molecules.
e) Van der Waals interactions are too weak to be significant.
d) Although they are weak bonds, van der Waals interactions help to reinforce the three-dimensional shapes of large molecules.
The partial charges on a water molecule occur because of __________.
a) the high electronegativity of hydrogen
b) ionic bonding
c) the unequal sharing of electrons between the hydrogen and the oxygen atoms of a water molecule
d) the achievement of a stable configuration by one atom of a bond but not by the other partner
e) widespread ionization
c) the unequal sharing of electrons between the hydrogen and the oxygen atoms of a water molecule
The use of radioactive isotopes in research includes all of the following, EXCEPT
a) Dating fossils
b) Drug development
c) Tracing atoms through metabolic processes
d) Diagnosing medical disorders
e) Cancer treatment
e) Cancer treatment
Starch consists of
a) unbranched amylose and branched amylopectin
b) branched amylose and branched amylopectin
c) unbranched amylose and unbranched amylopectin
d) None of the listed choices is correct.
a) unbranched amylose and branched amylopectin
Radioactive isotopes are useful in scientific research because __________.
a) they can be used as tracers to follow particular atoms and molecules through metabolic pathways, especially in medicine
b) they are not readily incorporated into biological reactions
c) they decay spontaneously and give off energy and subatomic particles
d) they are difficult to detect in small amounts, but living cells cannot distinguish them from the corresponding stable isotopes
e) All of the listed responses are correct.
a) they can be used as tracers to follow particular atoms and molecules through metabolic pathways, especially in medicine
What is ATP’s importance in a cell?
a) ATP stores energy in carbonyl groups. When a carbonyl group is removed, energy is released to be used in cellular processes.
b) ATP stores the potential to react with water, thereby removing a phosphate group and releasing energy for cellular processes.
c) ATP contains a long hydrocarbon tail and is important in storing energy.
d) ATP is an important component of cell membranes because it is nonpolar and hydrophobic.
e) ATP can add phosphate groups, thereby releasing energy that can be used in cellular processes.
b) ATP stores the potential to react with water, thereby removing a phosphate group and releasing energy for cellular processes.
What is the process by which monomers are linked together to form polymers?
a) monomerization
b) hydrolysis
c) protein formation
d) dehydration or condensation reactions
e) coiling
d) dehydration or condensation reactions
Generally, animals cannot digest (hydrolyze) the glycosidic linkages between the glucose molecules in cellulose. How then do cows get enough nutrients from eating grass?
a) Microorganisms in their digestive tracts hydrolyze the cellulose to individual glucose units.
b) Cows and other herbivores are exceptions and make some cellulose-digesting enzymes.
c) The flat teeth and strong stomachs of herbivores break the cellulose fibers so that the cows get enough nutrition from the cell contents.
d) They have to eat a lot of it.
e) All of the listed responses are correct.
a) Microorganisms in their digestive tracts hydrolyze the cellulose to individual glucose units.
Because molecules of water are farther apart in ice than in liquid water, __________.
a) ice vaporizes before liquid water does
b) ice floats
c) ice is denser than liquid water
d) ice expands when it melts
e) all of the lusted responses are correct
b) ice floats
Carbon atoms are the most versatile building blocks of the molecules used by living organisms because __________.
a) carbon is the central atom of carbon dioxide, a necessary molecule for photosynthesis
b) carbon is the central atom in urea, a molecule used by many living organisms to transport wastes from the body
c) each carbon atom acts as an intersection point from which a molecule can branch off in up to four directions
d) carbon can combine with hydrogen to form hydrocarbons
e) All of the listed responses are correct.
c) each carbon atom acts as an intersection point from which a molecule can branch off in up to four directions
Nonpolar molecules that cluster away from water molecules are called __________ molecules.
a) hydrophilic
b) hydrophobic
c) ionic
d) saponified (turned into soap by reaction with an alkali)
e) None of the listed responses is correct.
b) hydrophobic
In a hydrolysis reaction, __________, and in this process water is __________.
a) a polymer is broken up into its constituent monomers … consumed
b) a monomer is broken up into its constituent polymers … produced
c) monomers are assembled to produce a polymer … produced
d) a polymer is broken up into its constituent monomers … produced
e) monomers are assembled to produce a polymer … consumed
a) a polymer is broken up into its constituent monomers … consumed
A phospholipid consists of a
a) polar phosphate hydrophilic tail group and hydrophobic fatty acid head
b) non-polar phosphate-containing head group and polar fatty acid tail
c) polar phosphate-containing hydrophilic head group and hydrophobic fatty acid tail
d) non-polar phosphate-containing head group and non-polar fatty acid tail
c) polar phosphate-containing hydrophilic head group and hydrophobic fatty acid tail
The subunits (monomers) in cellulose are linked together by __________.
a) glycosidic linkages
b) ester linkages
c) peptide bonds
d) ionic bonds
e) phosphodiester linkages
a) glycosidic linkages
