Biology Module 6 Test
What is the ratio of carbohydrates in a monosaccharide?
1 carbon: 2 hydrogen: 1 oxygen
How do enzymes affect the speed of chemical reactions in the body?
it speeds it up
What happens to the speed of a chemical reaction when a catalyst is present?
it speeds up
macromolecule
large molecule formed by joining smaller organic molecules together
proton
positively charged particle in an atom's nucleus
Carbohydrates functions
provide energy
Lipid functions
store energy
Van der Waals forces
attractive forces between molecules
Which biological macromolecule is not considered a polymer?
a lipid
Homogenous
a mixture that has a uniform composition thought
Which of the following is an atom that has lost an electron?
a positive ion
Which of the following can be classified as a van der Waals force?
a weak electrostatic interaction between two polar molecules
Which property of water helps plants to transport water from their roots to their leaves?
adhesion
What is a radioactive isotope?
an atom whose nucleus is unstable and emits particles and energy
ion
atom that is negatively or positively charged because it has lost or gained one or more electrons
Bond energy is the amount of energy it takes to break a bond between two ___
atoms
atom
building blocks of matter; contains subatomic particles neutrons, protons, and electrons
Protein functions
building blocks of protein
What are the major classes of biological macromolecules?
carbohydrates, proteins, lipids, nucleic acid
amino acid
carbon compound joined by peptide bonds; building block of proteins
Which of the following can reduce the amount of energy needed for a chemical reaction to take place?
catalyst
nucleus
center of an atom; contains neutrons and protons
During a chemical reaction ___ break and reform
chemical bonds
endothermic reactions
chemical reaction that absorbs more energy that it releases
exothermic reactions
chemical reaction that release more energy than it absorbs
Which property causes water to from beads?
cohesion
mixture
combination of 2 or more different substances
nucleic acid
complex macromolecule that stores and communicates genetic information
molecule
compound whose atoms are held together by covalent bonds
water and carbon dioxide are examples of ____
compounds
A molecule is held together by ___
covalent bonds
A catalyst can ____ the amount of energy needed to start a chemical reaction
decrease
Which of the following compounds are examples of nucleic acids?
deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)
ionic bond
electrical attraction between 2 oppositely charged atoms or groups of atoms
Which of the following is not found in the nucleus of an atom?
electron
Which process changes a chlorine atom into a negative chloride ion?
electron gain
Two atoms may form several covalent bonds to share several pairs of _____
electrons
____ are made up of only one type of atom
elements
Chemical reaction
energy requiring process by which atoms or groups of atoms in substances are reorganized into different substances
Substrates are to____ as keys are to locks.
enzymes
Which of the following compounds can be classified as a proteins?
enzymes
____ are catalysts for chemical reactions in living things
enzymes
A solution is a mixture of substances that is ____ disturbed through the entire mixture
evenly
Scientists make observations and do experiments as a way to gather ___
evidence
A theory is a specific idea that has been proven to be true
false
An atom becomes an ion when its number of proton changes
false
Carbon's outer energy level is full
false
Not all chemical reactions involve changes in energy
false
Polar molecules have two regions with a light positive charge
false
Some ions are positively charged, and some ions have no changes
false
The three basic structures of carbon-based molecules are straight chain, bent chain, and ring chain
false
an exothermic chemical reaction absorbs more energy that it releases
false
chemical reactions can occur whether or not energy is added to the reactants
false
Which of the following are potential applications of radioactive isotopes?
food preservation, fossil dating, cancer treatment, medical imaging
Which of the following functions can be attributed to nucleic acids and nucleotides?
genetic information storage and transmission
Vertical rows are called?
groups
Which property allows water to resist changes in temperature?
high specific heat
solution
homogenous mixture formed when a substance is dissolved in another substance
activation energy
minimum amount of energy needed for reactants to form products in a chemical reaction
buffer
mixture that can react with an acid or a base to maintain in the pH within a specific range
polar molecule
molecule with oppositely charged regions
electron
negatively charged particle that occupies space around an atoms nucleus
Oil and water don't mix because ____ molecule can't easily dissolve in a polar molecule
nonpolar
DNA and RNA are nucleic acids polymers that are made up of?
nucleotides
A scientist begins his or her research by making _____ theories
observations
protein
organic compound made of amino acids joined by peptide bonds; primary building block of organisms
carbohydrates
organic compounds containing carbon, hydrogen, and oxygen in a ratio of one oxygen and two hydrogen atoms foe each carbon atom
Shared pairs of electrons fill the ___ energy levels of bonded atoms
outermost
Acids have
pH values < 7
Bases have
pH values >7
Which of the following factors influence enzyme activity?
pH, temperature
neutron
particle without a charge in an atoms nucleus
Which of the following joins amino acids together?
peptide bonds
Horizonal rows are called?
periods
Carbohydrates that provide structural support, like chitin, are usually?
polysaccharides
activation energy is the energy required to?
start a chemical reaction
Which of the following compounds can be classified as lipids?
steroids, unsaturated fatty acids, saturated fatty acids, phospholipids
Covalent bonds are generally very ____
strong
product
substance formed by a chemical reaction; located on the right side of the arrow in a chemical equation
solvent
substance in which another substance is dissolved
acid
substance that releases hydrogen ions (H+) when dissolved in water; an acidic solution has a pH less than 7
base
substance that releases hydroxide ions (OH-) when dissolved in water; a basic solution has a pH greater than 7
reactant
substances that exists before a chemical reaction starts; located on the left side of the arrow in a chemical equation
solute
substances that is dissolved in solvent
catalyst
substances that speeds up a chemical reaction by reducing the activation energy
What physical factors affect the action of enzymes?
temperature and pH
How are water molecules in a rain drop held together?
van der Waals forces
Quantitive data
volume, mass, tempature
hydrogen bond
weak electrostatic bond formed by the attraction of opposite charges between a hydrogen atom and an oxygen, fluorine, or nitrogen atom
active site
specific place where a substance binds on an enzymes
nucleotide
A subunit of nucleic acid formed from a simple sugar, a phosphate group, and a nitrogenous base.
Why is the active site of an enzyme important to enzyme activity?
It allows the enzyme to catalyze very specific reactions.
How does a substrate affect an enzyme?
It binds and makes it possible for the reaction to take place
Which of the following is not a property of water?
It combusts
Which properties of water make it a compound necessary for life to exist on our planet?
Its solid form is less dense than its liquid form; ice floats, It is an excellent solvent, It is adhesive and cohesive, It is a polar molecule capable of forming hydrogen bonds.
Qualitative data
Sounds, smells, sights
Why is the sequence of amino acids important to protein function?
The order of amino acids determines the shape a protein will take.
lipid
hydrophobic biological molecule composed mostly of carbon and hydrogen; fats, oils, and waxes
Where do enzymes act as catalyst?
in living things
polymer
large molecule formed from smaller repeating units of identical, or nearly identical, compounds linked by covalent bonds
Nucleic acid functions
map for making proteins
Which of the following functions can be attributed to lipids?
membrane and barrier formation, energy storage, building blocks for cholesterol and other hormones
enzyme
proteins that speeds up a biological reaction by lowering the activation energy needed to start the reaction
element
pure substance composed of only one type of atom; cannot be broken down into another substance by physical or chemical means
compound
pure substance with unique properties; formed when two or more different elements combine
substrate
reactant to which an enzyme binds
___ are the substances changed during a chemical reaction
reactants
Which statement is true of chemical equations?
reactants come before the arrow, products come after.
Equilibrium occurs when reactants and products are made at the ___
same rate
Which of the following molecules can be identified as carbohydrates?
simple sugars, disaccharides, glucose, polysaccharides
A ____ dissolves in a solution
solute
Blood plasma is an example of a
solvent
Heterogenous
the components in a mixture remain distant
pH
the measure of concentration of hydrogen atoms (H+) in a solution
Why are intermolecular forces, such as van der Waals forces, important to biological function? Multiple choice question.
they are easy to form and break apart, making them ideal for short-term interactions.
How do enzymes affect a chemical reaction, making it easier to occur?
they reduce the activation energy.
Carbon atoms can form covalent bonds with up to four atoms
true
Carbon atoms form the building blocks of most living things
true
Ions usually form when electrons are transferred from one atom to another
true
Slightly charged regions of water molecules form hydrogen bonds
true
The formation of an ion results in a full outermost energy level
true
Water is a polar molecule
true
activation energy is required for a chemical reaction to start
true
some chemical reactions release more energy than they absorb, while others absorb more energy than they release
true
theories can change over time as new evidence is discovered
true
isotope
two or more atoms of the same element having different numbers of neutrons
covalent bond
type of chemical bond formed when atoms share electrons
