A&P hw chapter 2
which of the following is an example of a suspension? - blood - rubbing alcohol - salt water - cytosol
blood
Calcium's atomic number is 20. It forms ions with 18 electrons. What is the electrical charge of a calcium ion? +1 -2 +2 -1
+2
an acid with a pH of 6 has ______ hydrogen ions than pure water - 10-fold more - 100-fold fewer - 100-fold more - 10-fold fewer
10-fold more
An atom with 3 electrons in its outermost (valence) shell may have a total of _____ electrons altogether. - 17 - 3 - 8 - 13
13
An atom with an atomic number of 10 and a mass number of 24 would have _____ - 14 neutrons - 24 protons - 14 electrons - 10 neutrons
14 neutrons
The numbers listed represent the number of electrons in the first, second, and third energy levels, respectively. On this basis, which of the following is an unstable or reactive atom? - 2, 8 - 2 - 2, 8, 8 - 2, 8, 1
2, 8, 1
Rank the chemical bonds from relatively weakest to strongest 1. ionic 2. covalent 3. hydrogen
3 < 1 < 2
What is the ratio of fatty acids to glycerol in triglycerides (neutral fats) - 4:1 - 3:1 - 1:1 - 2:1
3:1
Atom X has 17 protons. How many electrons are in its valence shell (outermost energy level)? - 10 - 5 - 7 -3
7
If atom X has an atomic number of 74 it would have which of the following? - 37 protons and 37 electrons - 37 protons and 37 neutrons - 74 protons - 37 electrons
74 protons
An atom of oxygen has an atomic number of 8 and a mass number of 18. How many of each type of subatomic particle does it contain? - 26 total subatomic particles - 8 protons, 8 neutrons, and 8 electrons - The atomic number and the mass number do not provide enough information to determine how many of each subatomic particle is present - 8 protons, 8 electrons, and 10 neutrons
8 protons, 8 electrons, 10 neutrons
What is the primary energy-transferring molecule in cells? - ATP - TACT - DNA - RNA
ATP
Which of the following can happen to a protein if it is denatured? - The degree of saturation in the fatty acid chains may be altered. - The primary structure of the protein may be altered. - An enzyme may no longer function properly. - The genetic code contained in the molecule may be altered.
An enzyme may no longer function properly
Match the following terms to their definitions: _______: usually, the first one or two letters of an element's name
Atomic symbol
which of the following would be regarded as an organic molecule? - CH4 - H2O - NaOH - NaCl
CH4
Although his cholesterol levels were not high, Mr. Martinez read that cholesterol wad bad for his health, so he eliminated all food and food products containing this molecule. He later found that his cholesterol level dropped only 20%. Why did it not drop more? - Cholesterol is present in plasma membranes, and you can only eliminate 20% of your body's cells safely. - Cholesterol is produced naturally by the liver, in addition to being ingested in foods. - Cholesterol is produced by the pancreas, and is essential for human life. - Cholesterol is present in all foods. Mr. Martinez did not actually remove all cholesterol from his diet, although he thought he did. - Cholesterol has a long half-life, and will take years to be broken down by the body.
Cholesterol is produced naturally by the liver, in addition to being ingested in foods
Select the most correct statement regarding nucleic acids. - Three forms exist: DNA, RNA, and tDNA. - RNA is a long, single-stranded molecule made up of the bases A, T, G, and C. - tDNA is considered a "molecular slave" of DNA during protein synthesis. - DNA is a long, double-stranded molecule made up of A, T, G, and C bases.
DNA is a long, double-stranded molecule made up of A, T, G, and C bases
A patient is hyperventilating. The "blowing off" of excessive carbon dioxide causes a decrease in blood H+ concentration. How can the carbonic acid-bicarbonate buffer system function to correct this imbalance? CO2 + H2O ↔ H2CO3 ↔ H+ + HCO3- - HCO3- binds with H+ to form H2CO3 and raise pH - H2CO3 dissociates to form more H+ and raise pH - HCO3- binds with H+ to form H2CO3 and lower pH - H2CO3 dissociates to form more H+ and lower pH
H2CO3 dissociates to form more H+ and lower pH
which of the following is a neutralization reaction? - NaOH⟶Na++OH− - NH3+H+⟶NH4+ - HCl+NaOH⟶NaCl+H2O - HCl⟶H++Cl−
HCl + NaOH --> NaCl + H2O
A 23-year-old male was riding his road bike in 100-degree heat, when he suddenly became nauseated and weak. He called 911 from his cell phone. When the ambulance came, the paramedics started intravenous therapy for severe dehydration. Which physical property and which physiological role of water caused the dehydration, and why? - High heat of vaporization; water was lost when evaporating from the skin to cool the body. - Reactivity; the increased temperature of water in the body made it unavailable for use by the body. - High heat capacity; water was lost when evaporating from the skin to cool the body. - High heat capacity; the heat from the sun was absorbed and 'neutralized' by the water within the body, making it unavailable for use by the body. - High heat of vaporization; the heat from the sun was absorbed and 'neutralized' by the water within the body, making it unavailable for use by the body.
High heat of vaporization; water was lost when evaporating from the skin to cool the body
Which of the following elements is necessary for proper conduction of nerve impulses? - I - P - Na - Fe
Na
Which of the following is a false statement about carbohydrates - Dietary glucose is primarily used to drive our metabolic pathways that produce energy. - The chemical composition of carbohydrates includes two oxygens and one hydrogen for every carbon present. - Glycogen is a complex carbohydrate formed by dehydration synthesis of glucose molecules. - Carbohydrates consist of monomers called simple sugars.
The chemical composition of carbohydrates includes two oxygens and one hydrogen for every carbon present
Which of the following is true? - Atomic weight is determined by the number of electrons in an atom of a given element. - Atomic weight is determined by the number of protons in an atom of a given element. - The chemical reactivity of an atom is based on the overall number of electrons in the atom. - The reactivity of an atom is based on the number of electrons in its outer valance.
The reactivity of an atom is based on the number of electrons in its outer valance
What does the formula C6H12O6 mean? - The molecular weight is 24. - The substance is a colloid. - There are 12 hydrogen, 6 carbon, and 6 oxygen atoms. - There are 6 calcium, 12 hydrogen, and 6 oxygen atoms.
There are 12 hydrogen, 6 carbon, and 6 oxygen atoms
Which of the following does NOT characterize proteins? - They appear to be the molecular carriers of coded hereditary information. - They have both functional and structural roles in the body. - They may be denatured or coagulated by heat or acidity. - Their function depends on their three-dimensional shape.
They appear to be the molecular carriers of coded hereditary information
______ is fat soluble, produced in the skin on exposure to UV radiation, and necessary for normal bone growth and function - cortisol - vitamin K - vitamin D - vitamin A
Vitamin D
choose the answer that best describes HCO3- - common in the liver - a proton donor - a weak acid - a bicarbonate ion
a bicarbonate ion
in general, the lipids that we refer to as oils have ______ - long fatty acid chains - a high degree of saturated bonds - a high degree of unsaturated bonds - a high water content
a high degree of unsaturated bonds
What is the classification of a solution with a pH of 8.3? - acidic solution - alkaline solution - neutral solution - buffered solution
alkaline solution
What is an ion? - an atom that has lost one or more neutrons - an atom that loses all of its protons - an atom that has either gained or lost electron(s) - an atom that is sharing electrons with another atom
an atom that has either gained or lost electron(s)
Which of the following best describes an isotope? - an atomic structural variation in which atoms have differing numbers of protons - an atomic structural variation in which atoms have differing numbers of neutrons - an atomic structural variation in which atoms have differing numbers of electrons - an atomic structural variation in which atoms have valence shell difference
an atomic structural variation in which atoms have differing numbers of neutrons
Which of the following would represent the attraction between an anion and a cation? - hydrogen bonds - a polar covalent bond - an ionic bond - a non-polar covalent bond
an ionic bond
choose the answer that best describes fibrous proteins - are very stable and insoluble in water - are cellular catalysts - are usually called enzymes - rarely exhibit secondary structure
are very stable and insoluble in water
Match the following particles to the correct description: ______: smallest particle of an element that retains its properties
atom
Match the following terms to their definitions: _____: number of protons in an atom
atomic number
Which of the following is not produced through chemical bonding? - adipose (fat) tissue - cells - the heart - atoms
atoms
In a covalent bond - atoms share one or more pairs of electrons - an atom gains one or more electrons from another atom to gain stability - an atom loses electrons to another to gain stability - adjacent atoms share a single electron
atoms share one or more pairs of electrons
Water is an important molecule because it ______ - has a low heat capacity - is non-polar - is a poor solvent since few thins dissolve in it - can form hydrogen bonds
can form hydrogen bonds
which four elements compromise approximately 96% of our body weight? - carbon, oxygen, hydrogen, and nitrogen - carbon, oxygen, iron, and potassium - carbon, oxygen, potassium, and sodium - carbon, oxygen, hydrogen, and potassium
carbon, oxygen, hydrogen, and nitrogen
Match the following particles to the correct description: _______: electrically charged particle due to loss of an electron
cation
When your muscles contract to move your body, such as during walking, work is done, and work requires energy. Based on the Law of Conservation of Energy, from where does this energy come? - new energy is created by our cells whenever we need it - chemical energy - heat - mechanical energy stored in ATP
chemical energy
Tendons are strong, rope-like structures that connect skeletal muscle to bone. Which of the following proteins would provide strength to a tendon? - molecular chaperone - albumin - actin - collagen
collagen
the single most abundant protein in the body is _____ - DNA - glucose - hemoglobin - collagen
collagen
match the following terms to their definitions (suspensions, colloids, solutions): _________: heterogeneous, will not settle
colloids
match the following terms to their definitions (element, mixture, compound): ____: dry ice (frozen carbon dioxide)
compound
match the following terms to their definitions (element, mixture, compound): _____: water
compound
Which of the following correctly ranks the types of chemical bonds, in order, from strongest to weakest? - hydrogen, ionic, covalent - ionic, hydrogen, covalent - hydrogen, covalent, ionic - covalent, ionic, hydrogen
covalent, ionic, hydrogen
ATP --> ADP + Pi is an example of a(n) ______ reaction - reversible - decomposition - synthesis - exchange
decomposition
Brenda is a 26-year-old female who is being discharged from the hospital after a vaginal delivery of an 8-pound healthy infant. Brenda is instructed by the nurse to eat a diet high in fiber and to drink 8 glasses of water per day to prevent constipation. Why? - The increased water intake allows more of the fiber to be absorbed by the body. - Fiber aids in the absorption of the excess volume of water in the digestive tract, allowing the increased water intake to be taken up into the body. - Dietary fiber adds bulk that cannot be absorbed by the body. This results in more water remaining in the digestive tract, easing the movement of feces through the bowel. - Fiber adds bulk to the diet that cannot be absorbed. This results in less water remaining in the digestive tract, easing the movement of feces through the bowel. - Fiber interferes with the absorption of the excess volume of water in the digestive tract, allowing the correct amount of water intake to be taken up into the body.
dietary fibers add bulk that cannot be absorbed by the body. This results in more water remaining in the digestive tract, easing the movement of feces through the bowel
sucrose is a _____ - disaccharide - triglyceride - polysaccharide - monosaccharide
disaccharide
match the following terms to their definitions (element, mixture, compound): _____: carbon
element
match the following terms to their definitions: ____: can be measured only by its effects on matter
energy
Which statement about enzymes is false - most enzymes can catalyze millions of reactions per minute - enzymes require contact with substrate in order to assume their active form - enzymes may be damaged by high temperature - enzymes may use coenzymes derived from vitamins or cofactors from metallic elements
enzymes require contact with substrate in order to assume their active form
Which of the following does not describe enzymes? - each enzyme is chemically specific - some enzymes are protein plus a cofactor - enzymes work by raising the energy of activation - some enzymes are purely protein
enzymes work by raising the energy of activation
t/f: Triglycerides are a poor source of stored energy
false
t/f: a dipeptide can be broken into two amino acids by dehydration synthesis
false
t/f: a weak base buffers an acid by completely dissociating and accepting all of the acids H+
false
t/f: about 60% to 80% of the volume of most living cells consists of organic compounds
false
Carbohydraes are stored in the liver and skeletal muscles in the form of ______. - triglycerides - cholesterol - glucose - glycogen
glycogen
Starch is the stored carbohydrate in plants, while _____ is the stored carbohydrate in animals - triglyceride - glycogen - glucose - cellulose
glycogen
Which property of water is demonstrated when we sweat? - high heat capacity - reactivity - cushioning - high heat of vaporization - polar solvent properties
high heat of vaporization
Match the following terms to their definitions: _____: a type of bond important in tying different parts of the same molecule together into a three-dimensional structure
hydrogen bond
What type of bond is formed between the oxygen atom of one water molecule and the hydrogen atom of another water molecule? - ionic bond - polar covalent bond - non-polar covalent bond - hydrogen bond
hydrogen bond
A high fever causes an enzyme to lose its three dimensional structure and function. Which bonds are broken when a protein denatures? - ionic bonds - hydrogen bonds - polar covalent bonds - non-polar covalent bonds
hydrogen bonds
Which type of reaction breaks the bonds between the subunits in a polymer chain? - dehydration synthesis - anabolic - neutralization - hydrolysis
hydrolysis
Which of these pairs indicates an incorrect coupling of reversible reactions? - anabolic and catabolic - breakdown and synthesis - dehydration synthesis and hydrolysis - hydrolysis and breakdown
hydrolysis and breakdown
Covalent bonds - involve the sharing of one to three pairs of electrons - always result in slight electrical charges at different atoms - always result in equal distribution of electrons between the atoms - involve the sharing of 8 pairs of electrons
involve the sharing of one to three pairs of electrons
Match the following terms to their definitions: ______: a bond in which electrons are completely lost or gained by the atoms involved
ionic bond
Which type of bond would most likely form between lithium and fluorine to make lithium floride? - ionic bond - non-polar covalent bond - hydrogen bond - polar covalent bond
ionic bond
Salts are always ____ - ionic compounds - hydrogen bonded - double covalent compounds - single covalent compounds
ionic compounds
How do ions form ionic bonds? - ions of the same type are drawn together because they are attracted to their own kind - one atom swaps all of its negative electrons for all of the other atom's positive protons - two atoms come together to share their electrons - ions of opposite electrical charges are attracted to each other to balance the charges
ions of opposite electrical charges are attracted to each other to balance the charges
the pH scale _____ - is based on the salinity of a solution - is linear - is based on the concentration of hydrogen ions in a solution - ranges from 1 to 7
is based on the concentration of hydrogen ions in a solution
Think about a 10% saline solution (saline refers to salt). Which of the following is a correct statement? - it contains 10% solvent and 90% solute - it contains 10% solute and 90% solvent - it contains 10% solvent and 90% water - it contains 10% salt and 90% solution
it contains 10% solute and 90% solvent
Why can dehydration be such a life threatening event? - The kidneys will excrete more sodium ions to make up for the lack of water intake. - It significantly alters the ratio of body water (solvent) to dissolved substances (solutes), such as sodium ions. - Blood chemistry is severely altered to the point that electrolyte concentrations of solutes such as sodium ions become too dilute. - Tissue interstitial fluid accumulates around vital organs, such as the heart, causing them to work less efficiently.
it significantly alters the ratio of body water (solvent) to dissolve substances (solutes), such as sodium ions
Which response provides the best explanation as to why ionic compounds easily dissociate in water? - its unusual polar arrangement allows more substances to dissolve in water than in any other chemical - non-polar organic molecules such as fats and waxes dissolve very well in water - as a polar molecule, it's difficult for water to dissociate inorganic compounds - water's polar nature helps it to easily dissociate most covalently bound compounds
its unusual polar arrangement allows more substances to dissolve in water than in any other chemical
Which of the following statements is false? - chemical reactions proceed more quickly at higher temperatures - catalysts increase the rate of chemical reactions, sometimes while undergoing reversible changes in shape - larger particles move faster than smaller ones and thus collide more frequently and more forcefully - chemical reactions progress at a faster rate when the reacting particles are present in higher numbers
larger particles move faster than smaller ones and thus collide more frequently and more forcefully
Which category of organic molecules includes cholesterol? - protein - carbohydrate - nucleic acids - lipid
lipid
match the following terms to their definitions: although a man who weighs 175 pounds on Earth would be lighter on the moon and heavier on Jupiter, his _____ would not be different
mass
Match the following terms to their definitions: _____: combined number of protons and neurons in an atom
mass number of an element
match the following terms to their definitions: _____: anything that occupies space and has mass
matter
match the following terms to their definitions (element, mixture, compound): ______: blood
mixture
Which of the following statements is true concerning the differences between compounds and mixtures? - mixtures consist of chemical bonds between the components - compounds can be separated by physical means - compounds are all homogenous - mixtures are all heterogeneous
mixtures are all heterogeneous
Match the following particles to the correct description: ______: combination of two or more atoms of the same element held together by chemical bonds
molecule
Based on the general theme of conservation, which of the following is most likely to happen if an athlete breaks his arm and must wear a cast and not use that arm for six weeks? - The muscles in the injured arm will get stronger to compensate for the injured bone. - Muscles in the injured arm will get smaller because they are not being used. - The muscles in the other arm will get stronger in order to help out. - The muscles in the injured arm will not change—only the bone was broken.
muscles in the injured arm will get smaller because they are not being used
Match the following particles to the correct description: ______: neutral subatomic particle
neutron
Which subatomic particles contribute to an atom's mass number but not its atomic number - neutrons - electrons - none of them - atomic number and atomic mass number are essentially the same thing - protons
neutrons
Atoms of oxygen have a total of 8 electrons. Are these atoms stable, and why or why not? - no, because the atoms have only 6 valence electrons, but need 8 for stability - yes, because oxygen is in the air we breathe and it doesn't hurt us - yes, because the Octet Rule says stable atoms have 8 electrons - no, because only atoms with 2 valence electrons are stable
no, because the atoms have only 6 valence electrons, but need 8 for stability
Match the following terms to their definitions: ____: a bond in which electrons are shared equally
non-polar covalent bond
With a family history of cardiovascular disease, which toast spread would be considered the most "heart healthy?" - butter containing butterfat - olive oil - margarine containing trans fats - lard (pig fat)
olive oil
How many phosphates would AMP have attached to it? - two - one - three - none
one
Lithium has an atomic number of 3. How many electrons are there in the outermost (valence) shell? - one - three - two - zero
one
Which of the following distinguishes hydrogen bonds from covalent bonds? - Only ionic bonds can form within molecules. - Only hydrogen bonds can form between molecules. - Only hydrogen bonds can form within molecules. - Only covalent bonds can form between molecules.
only hydrogen bonds can form between molecules
What explains the negative charge on the oxygen atom within the water molecule? -Oxygen atoms have a stronger pull on the electrons shared within a covalent bond formed between oxygen and hydrogen. - Hydrogen atoms have a stronger pull on the electrons shared within a covalent bond formed between oxygen and hydrogen. - Electrons are transferred from hydrogen to oxygen during the formation of an ionic bond. - Protons are transferred from oxygen to hydrogen during the formation of an ionic bond.
oxygen atoms have a stronger pull on the electrons shared within a covalent bond formed between oxygen and hydrogen
Which of the following is not a compound? - oxygen gas - methane (natural gas) - water - carbon dioxide
oxygen gas
blood loss due to a moderate hemorrhage has several adverse effects on patient wellbeing. Why would administering IV fluids alone not be sufficient to return a patient to health? - Potential risk for over-hydration due to excess fluid infusion is too great to give IV fluids alone. - Giving hypertonic IV fluids such as lactated ringers may cause more harm than good. - IV saline administration does not greatly alter blood sodium chemistry regardless of the amount of blood loss. - Oxygen-carrying red blood cells lost along with the fluid component must also be replaced.
oxygen-carrying red blood cells lost along with the fluid component must also be replaced
Which of the following does not describe uses for the ATP molecule? - mechanical work - chemical work - transport across membranes - pigment structure
pigment structure
Match the following terms to their definitions: _______: a bond in which electrons are shared unequally
polar covalent bond
A molecule of water (H2O) is formed by what type of bond? - polar covalent bonds - ionic covalent bonds - non-polar covalent bonds - weak bonds
polar covalent bonds
Formation of hydrogen bonds requires hydrogen atoms and what else? - polar covalent bonds - oxygen - water - ionic bonds
polar covalent bonds
When frying an egg, the protein albumin denatures and maintains only its ____ structure - tertiary - quaternary - secondary - primary
primary
What is a chain of more than 50 amino acids called? - nucleic acid - polysaccharide - polypeptide - protein
protein
Which organic molecules from the major structural materials of the body? - calcium salts in bones - lipids - carbohydrates - proteins
proteins
the basic structural material of the body consists of _____ - proteins - lipids - nucleic acids - carbohydrates
proteins
Which types of subatomic particles can be located within the nucleus of an atom? - neutrons only - protons and neutrons - protons and electrons - electrons only
protons and neutrons
Carbohydrates and proteins are built up from their basic building blocks by the ______. - addition of a water molecule between each two units - removal of a water molecule between each two units - addition of a carbon atom between each two units - removal of a carbon atom between each two units
removal of a water molecule between each two units
Why is it possible to safely drink a solution that contains a 50:50 mixture of equal concentrations of a strong acid and a strong base, either of which, if ingested separately, would be very caustic and damaging? - salt and water are formed when a strong acid and base are mixed - a reaction occurs, resulting in a mixture of only weak acids and bases - the strong acid and base each act as a buffer for one another - the damage caused by the acid is undone by the base - the mixture of a strong acid and base will still be very caustic if ingested
salt and water are formed when a strong acid and base are mixed
which of the following is true of protein structure? - peptide bonds join the amine group on one amino acid with the R group of another amino acid - peptide bonds are formed by hydrolysis - tertiary protein structure emerges when there is more than one peptide chain in a protein - secondary protein structures are caused by hydrogen bonding between adjacent amine and carboxyl groups
secondary protein structures are caused by hydrogen bonding between adjacent amine and carboxyl groups
What structural level is represented by the coiling of the protein chain backbone into an alpha helix? - quaternary structure - secondary structure - tertiary structure - primary structure
secondary strucure
The genetic information is coded in DNA by the ________. - three-dimensional structure of the double helix - regular alteration of sugar and phosphate molecules - arrangement of the histones - sequence of the nucleotides
sequence of the nucleotides
Mrs. Mulligan goes to her dentist and, after having a couple of cavities filled, her dentist strongly suggests that she reduce her intake of sodas and increase her intake of calcium phosphates in the foods she eats. Why? - Sodas contain lots of sugar that can dissolve the calcium carbonate in bone and teeth - Sodas are carbonated, and the increased carbon dioxide can dissolve the calcium carbonate in bone and teeth - Sodas contain lots of sugar that can dissolve the calcium phosphate in bone and teeth - Sodas are strong acids that can dissolve the calcium phosphate in bone and teeth - Sodas are strong bases that can dissolve the calcium phosphate in bone and teeth
sodas are strong acids that can dissolve the calcium phosphate in bone and teeth
Which of the following is the major positive ion outside cells? - hydrogen - potassium - magnesium - sodium
sodium
match the following terms to their definitions (suspensions, colloids, solutions): ______: homogeneous, will not settle
solutions
match the following terms to their definitions (suspensions, colloids, solutions): _______: will not scatter light
solutions
which of the following is a general function for a fibrous protein? - catalysis - transport - protein management - structural framework - body defense
structural framework
Which of the following is a product in the following reaction? glucose + fructose --> sucrose + H2O
sucrose
consider sweetened ice tea. Which of the following is a solute? - sugar - water - the beverage itself - ice
sugar
match the following terms to their definitions (suspensions, colloids, solutions): ________: heterogeneous, will settle
suspensions
Amino acids joining together to make a peptide is a good example of a(n) _____ reaction. - reversible - exchange - synthesis - decomposition
synthesis
Hydrogen bonds would be found in which of the following - a water molecule - the complex, three-dimensional structure of protein molecules - between any hydrogen atom that is covalently bonded to any other atom and the atom it is bonded to - the geometric patterns formed by salt crystals
the complex, three-dimensional structure of protein molecules
Which of the following is true of polar covalent bonds? - the electrons are shared unequally - the same number of electrons are gained by one atom as are lost by another - electrons are shared equally - they are rather weak bonds
the electrons are shared unequally
Salivary amylase is an enzyme produced by the salivary glands that breaks down carbohydrates. What will happen to this enzyme as it follows the food into the stomach where the pH drops to 2.5? - the enzyme will denature but retain its function - the enzyme will assume an alternate form and catalyze additional reactions - the enzyme will continue to function as it remains unchanged in chemical reactions - the enzyme will denature and become inactive
the enzyme will denature and become inactive
When an ionic bond forms, which part(s) of the atoms are directly involved? - both the protons and the electrons - the outermost electrons - the protons - the neutrons
the outermost electrons
A chemical reaction in which bonds are broken is usually associated with _____ - forming a larger molecule - the release of energy - a synthesis - the consumption of energy
the release of energy
Why can DNA be used to "fingerprint" a suspect in a crime? - DNA cannot be used to identify a suspect: all humans contain the same genes and DNA is, therefore, not unique to an individual. - The DNA determines the pattern of an individual's fingerprint, and can be 'read' to determine the fingerprint pattern for matching in a database. - The sequence, but not fragmentation pattern, of a person's DNA is unique to that individual. - The sequence and fragmentation pattern of a person's DNA is unique to that individual.
the sequence and fragmentation pattern of a person's DNA is unique to that individual
Which of the following is NOT one of the three basic steps involved in enzyme activity? - The substrate absorbs chemical energy from the enzyme after binding to its active site. - The enzyme's active site binds to the substrate(s) on which it acts, temporarily forming an enzyme-substrate complex. - The enzyme-substrate complex undergoes internal rearrangements that form the product(s). - The enzyme releases the product(s) of the reaction.
the substrate absorbs chemical energy from the enzyme after binding to its active site
What does CH4 mean? - this was involved in a redox reaction - there are four carbon and four hydrogen atoms - there is one carbon and four hydrogen atoms - this is an inorganic molecule
there is one carbon and four hydrogen atoms
How are the oxygen atoms bonded together in a molecule of oxygen gas (O2)? - They are bonded by an ionic bond. - They are bonded by a single covalent bond. - They are bonded by a double covalent bond. - They are bonded by a polar covalent bond.
they are bonded by a double covalent bond
In a DNA molecule, the phosphate serves ______. - as a code - to hold the molecular backbone together - to bind the sugars to their bases - as nucleotides
to hold the molecular backbone together
Which of the following is true about lipids? - lipids that serve as hormones are derived from glycolipids - lipids used as energy reserves in the body are stored as molecules of phospholipids - triglycerides are composed of three fatty acids and one glycerol and are stable because they do not dissolve in water - lipids found in the cell membrane are composed of one glycerol and three fatty acid chains and are called phospholipids
triglycerides are composed of three fatty acids and one glycerol and are stable because they do not dissolve in water
t/f: ATP is an unstable, high-energy molecule that provides body cells with a form of energy that is immediately usable.
true
t/f: Omega-3 fatty acids appear to decrease the risk of heart disease
true
t/f: The major function of DNA is to store the genetic instructions that are used during protein synthesis
true
t/f: a charged particle is generally called an ion or electrolyte
true
t/f: a chemical bond is an energy relationship between outer electrons and neighboring atoms
true
t/f: all organic compounds contain carbon
true
t/f: all salts are ions, but not all ions are salts
true
t/f: buffers resist abrupt and large changes in the pH of body fluids by releasing or binding ions
true
t/f: glucose is an example of a monosaccharide
true
t/f: hydrogen bonds are too weak to bind atoms together to form molecules, but they do hold different parts of a single large molecule in a specific three-dimensional shape
true
t/f: it is the difference in the R group that makes each amino acid chemically unique
true
t/f: mixtures are combinations of elements or compounds that are physically blended together but are not bound by chemical bonds.
true
t/f: the acidity of a solution reflects the concentration of free hydrogen ions in the solution
true
t/f: the atomic weight is an average of the relative weights (mass number) of all the isotopes of an element
true
t/f: the pH of body fluids must remain fairly constant for the body to maintain homeostasis
true
the lower the pH, the higher the hydrogen ion concentration
true
Phospholipids makes up most of the lipid part of the cell membrane. Since water exists on both the outside and inside of cells, which of the following phospholipid arrangements makes the most sense? - two back-to-back phospholipid layers with the polar heads facing out on both sides - a single layer of phospholipids with the polar heads facing outside the cell - two back-to-back phospholipid layers with the non-polar tails facing out on both sides - a single layer of phospholipids with the polar heads facing inside the cell
two back-to-back phospholipid layers with the polar heads facing out on both sides
Which of the following is not a result of hydrogen bonds? - Two hydrogen atoms join together to form a molecule of hydrogen gas. - Two strands of DNA are linked together taking a shape similar to a ladder. - An enzyme has a unique shape that allows it to bond only with specific molecules. - Some hair is straight, some wavy, and some very curly.
two hydrogen atoms join together to molecule of hydrogen gas
Which parts of atoms can interact (react) to form chemical bonds? - the nucleus of each atom - protons - valence electrons - the orbitals
valence electrons
What molecule must be lost when fatty acids are bonding to glycerol? - water - carbon dioxide - oxygen - hydrogen
water
match the following terms to their definitions: _____: is a function, of a varies with, gravity
weight
Which of the following statements is false? - The more hydrogen ions in a solution, the more acidic the solution. - When the hydrogen ion concentration decreases, the hydroxyl ion concentration also decreases. - When acids and bases are mixed, they react with each other to form water and a salt. - The pH of blood is slightly basic.
when the hydrogen ion concentration decreases, the hydroxyl ion concentration also decreases
Carbon atoms have four valence electrons. Are they likely to react with other atoms, and why or why not? - yes, because they can become more stable by doing so - no, because they have an even number of valence electrons so they are already stable - no, because they do not have enough valence electrons - yes, but only with other stable atoms
yes, because they can become more stable by doing so
