biochemistry test - unit 2 module 6
Order the substrate-enzyme interaction steps, with the first step at the top of the list.
1. the substrates bind to the active site, 2. the active site changes shapes and forms the enzyme-substrate complex, 3. the substrates react to form products, 4. the enzyme releases the products.
A triple covalent bond involves the sharing of how many electrons?
6
Many solutes readily dissolve in water because water is a ______________ molecule.
polar
Molecules that have an unequal distribution of charges are called ________________ ________________, meaning that they have oppositely charged regions.
polar molecules
Which describes molecules that have an unequal distribution of charges, meaning that they have oppositely charged regions?
polar molecules
Which are types of nucleic acids?
DNA and RNA
The ______________ ______________ of the elements organizes elements based on their properties
Periodic Table
True or false: Once an enzyme has participated in a chemical reaction, it is used up and can never be used again.
False
True or false: The ability of carbon atoms to bond to each other results in just one type of organic compound.
False
A mixture in which the components remain distinct is called a _____________ mixture.
Heterogeneous
Which of the following describes a mixture in which the components remain distinct?
Heterogeneous
________________ are molecules made from repeating units of identical or nearly identical compounds called monomers that are linked together by a series of covalent bonds.
Polymers
Why are atoms important?
They are the building blocks of all matter.
True or false: Inhibitors, pH, and temperature can all affect enzyme activity.
True
A nucleotide is composed of which of the following?
a nitrogen base, ribose sugar, phosphate group
A(n) _____________ releases hydrogen ions when dissolved in water. A(n) ______________ releases hydroxide ions when dissolved in water.
acid, base
Substances that release hydrogen ions when dissolved in water are called _______________.
acids
When dissolved in water, what substances release hydrogen ions?
acids
Which term describes the specific location where a substrate binds on an enzyme?
activate site
Enzymes reduce the ______________ _____________ required to start a chemical reaction in a biological process. This allows the reaction to proceed more quickly.
activation energy
The minimum amount of energy needed for reactants to form products in a chemical reaction is called the ___________ ___________.
activation energy
The minimum amount of energy needed for reactants to form products in a chemical reaction is called the _____________ ______________.
activation energy
Which of the following is the minimum energy needed for reactants to form products in a chemical reaction?
activation energy
_____________ _____________ are small compounds that are made of carbon, nitrogen, oxygen, hydrogen, and sometimes sulfur.
amino acids
__________________ are important because they are the building blocks of all kinds of matter, including living organisms.
atoms
What are characteristics of ionic bonds?
attraction between ions and weak forces between molecules
Van der Waal's forces are...?
attractions between molecules
Which best describes van der Waals forces in water?
attractive forces between molecules, cause water to form droplets
What are substances that release hydroxide ions when they are dissolved in water called?
bases
What are examples of colloids?
blood, milk, ink
What is a mixture that can react with acids or bases to keep the pH in a particular range?
buffer
A ______________ is a compound composed of carbon, hydrogen, and oxygen in a ratio of one oxygen and two hydrogen atoms for each carbon atom.
carbohydrate
Which is a compound composed of carbon, hydrogen, and oxygen in a ratio of one oxygen and two hydrogen atoms for each carbon atom?
carbohydrate
Which types of biological macromolecules store energy?
carbohydrates and lipids
Organic chemistry is the study of organic compounds, which are compounds that contain ______________.
carbon
The element _____________ is a component of almost all biological molecules.
carbon
Which are practical applications of isotopes?
carbon dating and diagnosing disease
What is the name given to a substance that lowers the activation energy needed to start a chemical reaction?
catalyst
What occurs during a chemical change, but not during a physical change?
chemical bonds are broken and formed, different substances are formed
The process by which atoms or groups of atoms in substances are reorganized into different substances is called a _____________ ______________.
chemical reaction
Which is the process by which atoms or groups of atoms in substances are reorganized into different substances?
chemical reaction
In a _____________ change, different substances are formed. In a _____________ change, a substance's appearance but not its composition is changed.
chemical, physical
Identify properties of water that are due to hydrogen bonding.
cohesion, adhesion, and density
Which is a heterogeneous mixture in which the particles do not settle out?
colloid
A pure substance formed when two or more different elements combine is called a(n) _____________.
compound
A pure substance formed when two or more different elements combine is called a(n) _______________.
compound
Which is a pure substance formed when two or more different elements combine?
compound
The chemical bond that forms when electrons are shared is called a ______________ ____________ .
covalent bond
Which type of bond is formed when two atoms share electrons?
covalent bond
_____________ bonds involve sharing of electrons between atoms, while _____________ bonds involve the movement of electrons from one atom to the other.
covalent, ionic
A ____________ covalent bond involves the sharing of four electrons.
double
A negatively charged particle found outside the nucleus is called a(n) __________________.
electron
The subatomic particles directly involved in forming chemical bonds are ______________.
electrons
A(n) _________________ is a pure substance that cannot be broken down into other substances by physical or chemical means.
element
In every chemical reaction, there is a change in _____________ caused by the making and breaking of chemical bonds as reactants form products.
energy
Temperature and pH are two factors that affect ______________ activity.
enzyme
Special proteins called _______________ are the biological catalysts that speed up the rate of chemical reactions in biological processes.
enzymes
Potassium (K), Sodium (Na), and Hydrogen (H) are located in the same column, or _______ of the periodic table.
group
What is a role of ions in living things?
help transmit signals related to the senses
Which are steroids?
hormones, cholesterol
Which is a weak interaction involving a hydrogen atom, and a fluorine, oxygen, or nitrogen atom from a different molecule?
hydrogen bond
A combination of two or more substances in which each substance retains its individual characteristics and properties is called a ___________.
mixture
A ___________ is a compound in which the atoms are help together by covalent bonds.
molecule
Which subatomic particle exists within the area of the nucleus and has no electrical charge?
neutron
DNA and RNA are examples of ____________ acids.
nucleic
Which are complex macromolecules that store and transmit genetic information in cells?
nucleic acids
A(n) _____________ is composed of a ribose sugar, a phosphate group, and a nitrogen-containing base.
nucleotide
Nucleic acids are made up of smaller repeating subunits composed of carbon, nitrogen, oxygen, phosphorus, and hydrogen atoms, called _____________.
nucleotides
What term describes the smaller repeating subunits that make up nucleic acids?
nucleotides
What is the center of the atom where neutrons and protons are located called?
nucleus
The measure of concentration of H+ in a solution is called ______________.
pH
Which type of energy level is least stable?
partially filled energy level
In the periodic table, horizontal rows are called ____________, while vertical columns are called ____________.
periods, groups
______________ are a type of lipid, and include substances such as cholesterol and hormones.
steroids
A reactant that binds to the enzyme is called a _______________.
substrate
What is the term used for reactants that bind to an enzyme?
subtrate
Over time, the particles in a ____________ settle to the bottom.
suspension
A weak force of attraction between molecules that is important in biological molecules is know as _________ __________ __________ __________.
van der Waal's force
Regions of opposite charge cause weak electrostatic attractions between molecules called _____________ _____________ _____________ _____________.
van der Waal's forces
Which term describes weak electrostatic attractions between molecules related to regions of opposite charge?
van der Waals forces
Lipids are hydrophobic, which means they do not dissolve in ____________.
water
What is the primary function of lipids?
Energy storage
What type of macromolecule is responsible for the structure and function of the cell membrane?
Phospholipids
How do suspensions differ from solutions?
In suspensions, particles settle to the bottom. In solutions, the particles do not settle, a suspension is a heterogeneous mixture. A solution is a homogeneous mixture.
Which explain ways that the periodic table of elements is useful?
It organizes information about known elements, it allows the properties of undiscovered elements to predicted.
What are the major categories of biological macromolecules?
Lipids, carbohydrates, nucleic acids, proteins
What is a characteristic of a balanced equation?
The number of atoms of each element on the reactant side must equal the number of atoms of the same element on the product side.
An atom that has gained or lost one or more electrons becomes a(n) _________ and carries an electric charge.
ion
Which term describes an atom that has gained or lost one or more electrons and carries an electric charge?
ion
A(n) ____________ ____________ is an electrical attraction between two oppositely charged atoms or groups of atoms.
ionic bond
What describes an electrical attraction between two oppositely charged atoms or groups of atoms?
ionic bond
In living things, ____________ help maintain homeostasis and help transmit signals related to the senses.
ions
Atoms of the same element that have different numbers of neutrons are called _______________.
isotopes
Carbon dating is an example of a practical application of ________________.
isotopes
The basic structure of a _____ includes a fatty acid tail made up of a chain of carbon atoms bonded to hydrogen and other carbon atoms by single or double bonds.
lipid
_______________ are molecules made mostly of carbon and hydrogen that make up the fats, oils, and waxes.
lipids
Large molecules that are formed by joining smaller organic molecules together are called _____________.
macromolecules
The law of conservation of ______________ states that in chemical reactions, matter cannot be created or destroyed.
mass
Anything that has mass and takes up space is, by definition, _____________.
matter
The ____________, the substances formed during the reaction, are shown on the right side of the arrow in a chemical equation.
products
Which term describes the substances formed during the reaction, which are shown on the right side of the arrow in a chemical equation?
products
Which is a compound made of small carbon compounds called amino acids?
protein
Your muscles, skin, and hair are made of _____________.
proteins
The particles located in the nucleus that have a positive charge are called ________________.
protons
Which are subatomic particles found in atoms?
protons, neutrons, electrons
A chemical equation shows the ____________, the starting substances, on the left side of the arrow.
reactants
Which term describes the starting substances, which are shown on the left side of the arrow in a chemical equation?
reactants
Lipids that have tail chains with only single bonds between the carbon atoms are called ____________ ____________ because no more hydrogens can bond to the tail.
saturated fats
Lipids that have tail chains with only single bonds between the carbon atoms are called ______________ _____________ because no more hydrogens can bond to the tail.
saturated fats
What are characteristics of covalent bonds?
single, double, and triple bonds and sharing of electrons
A _____________ is the substance that is dissolved in the solvent.
solute
Another name for a homogeneous mixture is a _______________.
solution
What is the term used for a homogeneous mixture?
solution
Which is a substance in which another substance is dissolved?
solvent
Why are some isotopes radioactive?
some nuclei are unstable and emit radiation during decay
Protons, neutrons and electrons are ___________ __________________ _______________ _________ ___________ ___________.
the component parts of an atom.
What characteristic is used to distinguish monosaccharides, disaccharides, and polysaccharides?
the number of units in the chain
What are the functions of proteins?
transporting substances, controlling cell growth, communicating signals, speeding up chemical reactions
True or false: Because of hydrogen bonding, ice floats on liquid water.
true
True or false: Water forms droplets due to van der Waals forces.
true
True or false: Water's solvent properties result from polarity.
true