The apoenzyme portion of a holoenzyme _____________________.
the protein portion of enzyme responsible for specificity
is the non-protein cofactor required for activity
provides energy for the reaction
denatures under high temperature
Isotopes of an element have different numbers of _________________.
neutrons
electrons
all of these
protons
The high heat of vaporization of water is significant because it _________________.
prevents hydrogen bonding
decreases metabolic rates
causes ice to sink
allows the body to cool through sweating
Which of the following is an example of a medical use of radioactive isotopes?
biological tracers
all of these
diagnostic imaging
radiation therapy for cancer
The atomic number of an element is equal to the number of _________________.
electrons
protons
all of these
neutrons
The process that joins monomers to form polymers by removing water is called __________________.
neutralization
all of these
hydrolysis
dehydration synthesis
Proteins are the most functionally diverse macromolecule group because _______________.
they are nonpolar and stable
the sequence of 20 amino acids can form countless combos
they are composed only of hydrogen and oxygen
their structure is determined only by temperature
Which subatomic particle carries a negative charge?
electron
proton
neutron
Glycogen is primarily stored in which two organs?
liver and skeletal muscle
stomach and pancreas
heart and lungs
brain and kidneys
The structure of ATP is most similar to ________________.
a monosaccharide
an amino acid
a triglyceride
a nucleotide
The most abundant inorganic compound in the human body is _________________.
oxygen
sodium chloride
water
carbon dioxide
The main energy currency of cells is _________.
ATP
The phospholipid bilayer of the plasma membrane is essential because ___________________________.
it provides rigid support
it allows all substances to pass freely
it forms a selective barrier due to hydrophobic/hydrophilic
it is composed entirely of carbohydrates
Explain the difference between kinetic and potential energy and give an example of each in the human body.
PE is stored energy, such as the energy in ATP or chemical bonds in glucose. KE is energy in motion, such as muscle contraction or nerve impulses that use ATP
The process of hydrolysis is important in metabolism because it _________________________________.
breaks down polymers into smaller units
converts ATP into ADP and phosphate
removes water to form bonds
joins monomers together
Which of the following accurately describes DNA?
Double-stranded, stores genetic information
Contains the sugar ribose and base uracil
Forms from the translation process
Single-stranded and found mainly in the cytoplasm
Which of the following best describes an endergonic reaction?
requires enzymes to occur
absorbs energy
releases energy
occurs only in the absence of oxygen
Explain what would happen to a protein’s function if it would be subjected to high fever or extreme pH.
protein could become denatured due to high temp
Name the monomer of nucleic acids.
nucleotides
Explain why fluid and electrolyte balance is critical for human health.
Fluid and electrolyte balance is essential for maintaining normal hydration, nerve impulses, muscle contraction, blood pressure, and overall cellular function.
Name the basic monomer of lipids.
fatty acids and glycerol
What form of energy is used to transmit messages from one part of the body to another?
chemical energy
mechanical energy
radiant energy
potential energy
Name the monomer of proteins
amino acids
The process of breaking down glycogen into glucose monomers is an example of _________________.
dehydration synthesis
oxidation
reduction
hydrolysis
The most common element combinations that form organic molecules include ___________________.
Na, Cl, K, Ca
C, H, O, N, P, S
P, S, I, Se
Fe, Cu, Zn, Mg
Enzymes are a part of which macromolecule group?
proteins
Enzymes function by __________________________.
becoming permanently altered in the chemical reaction
lowering the amount of activation energy
increasing the amount of activation energy
slowing down chemical reactions
The primary function of carbohydrates in the human body is ________________________.
enzyme production
energy source
insulation and protection
structural support
When a protein’s hydrogen bonds are broken due to high temperature or pH changes, the process is called ___________________.
deamination
denaturation
synthesis
polymerization
The most abundant and versatile macromolecule in the human body is ___________________________________.
carbohydrates
lipids
proteins
nucleic acids
Which part of an amino acid gives each one its unique chemical properties?
Amino group
Hydrogen atom
Carboxyl group
R (side) group
In a chemical equation, the substances on the left side of the arrow are the:
catalysts
enzymes
products
reactants
Covalent bonds are formed by ________________.
hydrogen bonding between polar molecules
the sharing of electron pairs
the transfer of electrons
the attraction between oppositely charged ions
The most important role of nucleic acids is to ____________________________.
store and transmit genetic information
form biological membranes
provide quick energy
catalyze metabolic reactions
Which type of reaction results in the formation of larger molecules from smaller building blocks?
Decomposition reaction
Synthesis reaction
Exchange reaction
Oxidation reaction
Describe why energy conversions are considered to be “inefficient”?
Energy conversions are inefficient because some energy is always lost as heat or other unusable forms during the process.
The process that breaks down polymers into monomers by adding water is called ____________.
all of these
dehydration synthesis
hydrolysis
neutralization
Why are buffers critical in the human body?
Buffers are critical because they maintain a stable pH in body fluids, which is essential for enzyme function, chemical reactions, and overall cellular health.
During hydrolysis reactions, _______________________________________________.
energy is absorbed
water is added to break bonds
water is removed to form bonds
bonds are formed between monomers
Which macromolecule type serves as enzymes, hormones, and antibodies?
proteins
nucleic acids
carbohydrates
lipids
The energy stored in ATP is located in its _______________________.
adenine base
nitrogen atoms
ribose sugar
high-energy phosphate bonds
Which type of lipid is most important in cell membrane structure?
steroid
phospholipid
wax
triglyceride
Which of the following is NOT a function of proteins in the human body?
Energy storage
Transport and movement
Hormone regulation
Enzymatic catalysis
Which of the following is an example of an inorganic cofactor that is part of a holoenzyme?
NAD+
Zinc ion (Zn2+)
ATP
DNA
Which statement about hydrogen bonds is FALSE?
They form between partially charged atoms.
They are responsible for the shape of DNA molecules.
They are strong covalent bonds.
They help water remain liquid at room temperature.
Describe the significance of water being the universal solvent in the human body.
Water’s polarity allows it to dissolve many substances, including salts, sugars, enables nutrient transport, waste removal, chemical rxns occur
An acid is a compound that ____________________.
accepts hydrogen ions (H+) in solution
increases pH in solution
releases hydrogen ions (H+) in solution
Neutralizes bases by releasing hydroxide ions (OH-)
Name the monomer of carbohydrates
monosaccharides
Which statement about lipids is TRUE?
They are insoluble in water but soluble in other lipids.
They are composed of repeating amino acid units.
They are all polar molecules.
They are the body’s main immediate energy source.
Which macromolecule serves as the primary short-term energy source for most cells?
carbohydrates
lipids
nucleic acids
proteins
The polarity of water contributes to all of the following EXCEPT ______________.
formation of nonpolar covalent bonds
high heat capacity
cohesion between molecules
ability to dissolve salts
The sequence of amino acids in a protein represents its _______________________.
quaternary structure
primary structure
secondary structure
tertiary structure
Which of the following best defines an element?
A form of energy that has mass
A combination of two or more compounds
A substance that cannot be broken down by normal means
A substance that can be broken down into simpler substances
A substance that stabilizes pH by releasing or binding hydrogen ions is a(n) _______________.
electrolyte
acid
base
buffer
Enzyme activity can be affected by all of the following EXCEPT __________________________.
concentration of enzyme or substrate
pH
DNA sequence
temperature
When a protein is denatured, it _______________________.
maintains its function
forms peptide bonds
loses shape and function
becomes more reactive
What are molecular chaperones, and what is their function in the cell?
Molecular chaperones are special proteins that assist other proteins in folding into their correct 3D shapes. They help prevent misfolding
The process of joining two monosaccharides to form a disaccharide involves a(n) _______________________.
oxidation reaction
reduction reaction
hydrolysis reaction
dehydration synthesis reaction
Describe what would happen to a chemical reaction in the body if the enzyme required for it was missing.
The reaction would occur much more slowly or may not occur at all under normal physiological conditions.
A solution with a pH of 8 is _____________________.
a strong acid
a strong base
a weak base
a weak acid
Why is it important that some radioisotopes used in diagnostic imaging have short half-lives?
Short half-lives are important because the radioisotopes decay quickly, minimizing radiation exposure to the patient while still providing enough time to produc
The formation of peptide bonds between amino acids occurs through ___________________.
dehydration synthesis
hydrolysis
neutralization
oxidation
A decomposition reaction is represented as:
AB + CD --> AD + BC
AB --> A + B
A + B --> AB
AB + C --> A + BC
The smallest unit of an element that still retains the properties of that element is called a(n) ________________.
molecule
atom
compound
proton
What form of energy is found in the foods we eat?
mechanical energy
electrical energy
chemical energy
all of these
The term polar molecule refers to ________________________________________.
A molecule held together by nonpolar covalent bonds
A molecule with equal charge distribution
A molecule that lacks hydrogen atoms
A molecule with an uneven distribution of charge
Explain why water’s cohesion is important for processes like capillary action in plants or blood flow in humans.
Cohesion allows water molecules to stick together, helping it move through narrow vessels and tubes efficiently.
An ionic bond is formed when ___________________.
to ions repel each other
electrons are shared between two atoms
electrons are transferred from one atom to another
two atoms share protons
The primary role of triglycerides in the human body is to _____________.
form the protective phospholipid bilayer
provide insulation and long-term energy storage
store genetic information
catalyze metabolic reactions
Hemoglobin functions as a _______________________.
enzyme for digestion
hormone regulating blood sugar
transport protein carrying oxygen
structural protein providing tensile strength
Explain the significance of water’s high heat capacity and high heat of vaporization in maintaining homeostasis.
helps the body resist sudden temperature changes, keeping cells and tissues stable. high heat of vapor. allows the body to cool when sweating
Which lipid molecule acts as a chemical messenger in the body?
Phospholipid
Triglyceride
Steroid
Cholesterol
Which of the following best describes an exergonic reaction?
absorbs energy
releases energy
occurs only in the absence of oxygen
requires enzymes to occur
In DNA, the complementary base to Adenine would be __________________.
Glycine
Thymine
Guanine
Cytosine
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