chapter 2 basic chemistry srudu
Which bases are found in RNA?
Adenine, uracil, guanine, and cytosin
Which functional group of substances increases the rates of chemical reactions by at least a million-fold, and is essential to virtually every biochemical reaction in the body?
Catalysts (enzymes)
Disaccharides are formed by which type of reaction?
Dehydration synthesis.
When dissolved in body fluids, salts easily separate into their ions. What is this process called?
Dissociation
Which type of bond is an important intramolecular bond, which helps to bind different parts of the same molecule together into a special 3-dimensional shape?
Hydrogen bond
Which of the following statements regarding hydrogen bonds is INCORRECT?
Hydrogen bonds are the strong bonds which help to maintain the structure of protein molecules.
The conversion of sucrose to glucose and fructose is accomplished by which type of reaction?
Hydrolysis
Which type of bond is formed when electrons are completely transferred from one atom to another?
Ionic bond
Which of the following statements regarding isotopes is TRUE?
Isotopes have the same number of protons and electrons, but differ in the number of neutrons they contain AND the chemical properties of all of an element's isotopes are exactly the same.
Which of the following is a disaccharide?
Lactose
The nucleus of an atom is the location of which kinds of subatomic particles?
Neutrons and protons.
Which of the substances listed below is an organic compound?
Nucleic acid
The modern model of atomic structure, involving regions around the nucleus in which a given electron or electron-pair is most likely to be found is called which of the following?
Orbital model.
Solution A has a pH of 4. Solution B has a pH of 13. Identify the correct statement.
Solution A is more basic than solution B (Solution B has more hydrogen ions).
Which of the following is a polysaccharide?
Starch.
Most of the reactions that take place for the body to repair damaged tissues are classified as which of the following type of chemical reaction?
Synthesis
What is the difference between glucose, sucrose, and glycogen?
The number of saccharide molecules varies
What is the difference in hydrogen ion concentration between gastric juice (pH=2.0) and coffee (pH=5.0)?
There are 1000 times fewer hydrogen ions in coffee than in gastric juice.
Which of the following statements is NOT true of hydrogen bonds?
They are one of the strongest bonds.
Which of the following accurately describes enzymes?
They are organic catalysts.
When a substance, that is dissolved in water, releases hydrogen ions (H+) in detectable amounts, and tends to lower the pH of the resulting solution, that substance is termed a(n):
acid
A cell's energy requirements are met by releasing bond energy from certain high-energy phosphate-bonds. The break-down of one of the compounds listed below provides an abundant, readily available source of energy. This compound is
adenosine triphosphate (ATP).
Proteins are made up of many:
amino acid molecules.
The sum of the protons and neutrons contained in the nucleus of an atom is known as its ________.
atomic mass number
An element is a substance that:
cannot be decomposed or broken down into simpler substances by ordinary chemical means.
When two atoms share one or more electrons the reaction is a/an _______ type of bonding.
covalent
If neutral atoms become positive ions, they:
lose electrons
A positive ion has
lost an electron.
An isotope is an atom that varies in the number of _________.
neutrons
Chemical activity between atoms usually involves
outer shell electrons.
The atomic number of an element is determined by the number of:
protons
The more acidic a solution is
the more hydrogen ions (H+) ions it contains.
If a solution has a pH of 6.0, then
the number of hydrogen ions (H+) is greater than the number of hydroxyl ions (OH-).
The atomic mass number is equal to
the number of neutrons and protons in its atoms
The most abundant inorganic compound found in the human body is
water
