CH2 study questions] Flashcards
Chemical energy is __________.
energy stored in bonds between atoms and
a form of potential energy
Which of the following is an example of the conversion of potential energy into kinetic energy?
Synthesis of ATP from glucose
ATP hydrolysis to drive muscle contraction
Digestion of protein in the stomach
Pumping ions across a cell membrane
ATP hydrolysis to drive muscle contraction
The four elements that comprise 96% of living matter are __________.
carbon, hydrogen, nitrogen, oxygen
An atom’s nucleus contains __________.
protons and neutrons
The element lithium has 3 protons and 4 neutrons in its nucleus. Its mass number is __________.
7
When atoms of two different elements bind together, they form a(n) __________.
compound
Which of the following mixture(s) are homogeneous?
Colloids
Solutions
Suspensions
Both colloids and suspensions
solutions
The most important determinant of an atom’s bonding behavior is __________.
the number of valence shell electrons
When atoms gain electrons, __________.
the atoms become negatively charged
Ionic bonds connect atoms together by __________.
charge attractions
Covalent bonds occur when __________.
electrons are shared between atoms
An atom will tend to be electronegative if __________.
it lacks only 1–2 electrons in the valence shell
Water, H2O, is a polar molecule. Oxygen is electronegative and hydrogen is electropositive. This means that __________.
the oxygen pulls electrons away from hydrogen and becomes more negative
Hydrogen bonds are similar to ionic bonds because __________.
they both are due to opposite charge attractions
In a chemical reaction, ___________ join to form __________.
reactants; products
Water’s unique properties like high heat capacity, high heat of vaporization, and universal solvent can be attributed to its __________.
ability to form hydrogen bonds
When chemical equilibrium is reached, __________.
no further net change in the amounts of reactants and products occurs
What will be the effect on a chemical reaction if the concentration of reactants is increased?
The speed of the reaction will increase.
A substance that is very acidic may have a pH of 1 or 2. This means that the acidic substance __________.
has a high concentration of H+ ions
A buffer will release H+ ions if the blood pH __________.
rises (becomes more basic)
The four major organic compounds that comprise our bodies are __________.
proteins, carbohydrates, lipids, nucleic acids
The major function of carbohydrates in the body is __________.
as cellular fuel
Which type of reaction occurs when biological molecules are broken down?
Hydrolysis
The three major subclasses of lipids include phospholipids, steroids, and __________.
triglycerides
The major building blocks for proteins are __________.
amino acids
Functions of proteins do not include acting as __________.
genes
The quaternary level of protein structure involves __________.
aggregations of polypeptides forming a complex protein
An enzyme’s ____________ is the molecule upon which an enzyme acts.
substrate
Increasing the concentration of an enzyme’s substrate (up to a point) would ___________ the reaction.
speed up
The major building blocks of nucleic acids are __________.
nucleotides
The four DNA nucleotides are __________.
adenine, thymine, cytosine, guanine
Which of the following is not a metabolic function of ATP?
Providing energy for diffusion
Substances that cannot be broken down into simpler substances are defined as ________.
elements
Energy in action is defined as _______ energy.
kinetic
When you row a boat, your arms provide which type of energy?
mechanical
When energy is converted from one form to another, some of the original energy is “lost” as ________.
heat
Which of the following is not one of the four major elements in the human body?
Hydrogen
Calcium
Nitrogen
Oxygen
calcium
The atomic number is always equal to the number of _______ in an atom.
protons
Isotopes have the same number of _______ but differ in the number of ________.
Isotopes have the same number of _______ but differ in the number of ________.
If an atom gains an electron, the resulting charge of that atom is more _________.
negative
Which spontaneously decompose into more stable atoms?
Radioisotopes
Which of the following is not a compound?
H2O
NaCl
O2
C6H12O6
o2
The following are electrons in the electron shells of four atoms. Which atom would most likely be reactive?
2, 8, 7
An ionic bond is formed between _______.
a cation and an anion
Which type of bond is formed when electrons are shared unequally between atoms?
Polar covalent
Which of the following statements is true of solvents?
They are usually solids.
They are present in smaller amounts in a solution.
Water is the main solvent in the body.
They are tiny particles.
Water is the main solvent in the body.
Building muscle tissue is an example of which type of reaction?
synthesis
All of the following affect the rate of a reaction except __________.
density
Bonds are broken during which type of reaction?
Catabolic
An enzyme is an example of a _________.
catalyst
Which of the following is not a reason for the irreversibility of chemical reactions in cells?
Chemical reactions that release energy would require energy to be reversed.
A product might be continually removed from the reaction site.
Biological reactions can only proceed in a single direction.
A product might be expelled from
the body.
Biological reactions can only proceed in a single direction.
A steroid is an example of _________.
lipid
Which of the following is not a function of water?
Body temperature regulation
Source of electrolytes
Universal solvent
Protection from mechanical damage
Source of electrolytes
Which pH indicates a weak base?
- 0
- 8
- 4
- 0
7.4
Which of the following describes the tertiary structure of proteins?
α-helical or β-pleated regions of the polypeptide chain folded upon one another
A substance that dissociates into cations and hydroxyl ions is __________.
a base
Which substance is the primary energy-transferring molecule in the cell?
ATP
know the structure of lipid
mountain
know structure of functional protein
loop
know structure of nucleotide
valence bonds
know structure of polysaccharide
chain monosaccharides
know structure of monosaccharide
hexgonal box
know polymer structure
.
Know tertiary structure
.