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