Which of the following is an important characteristic of lipids?
They are nonpolar.
Which of the following situations BEST demonstrates solubility?
A teaspoon of salt disappears when stirred into a glass of water.
**Hydrophobic solutes are generally soluble/insoluble (choose one) in water, due to the presence of _____ covalent bonds between the atoms in each solute molecule.
insoluble; nonpolar
**Water readily dissolves ions because the atoms in water molecules are bonded by _____ bonds.
polar covalent
**For ions in solution, the measurement unit that considers the number of electrical charges carried by each ion is the _____.
equivalent
Which compound is hydrophobic?
Butter
What is a substance that can moderate the change in pH of a solution?
A buffer
What would cause a protein response rate to be maximal?
The protein binding sites are saturated.
Lemon juice has a pH of about 2.0, compared to a pH of about 1.0 for stomach acid. Therefore, the concentration of H+ in stomach juice is ________ than that of lemon juice.
10 times higher
Proteins that bind signal molecules and initiate cellular responses are called ________
receptors
A protein that no longer functions because its shape has changed (e.g., as a result of heating) has been ________.
denatured
Stanley Miller set out to demonstrate an explanation for the origins of organic molecules using a combination of simple organic molecules, heat and periodic burst of electricity through the mixture, ultimately producing what kind of molecules?
amino acids
Glycosylated molecules are those formed with which group of organic compounds?
carbohydrates
Cells regulate their level of activity by regulating the amount of proteins present in the cell at any given time, so an up regulation of enzymes would be expected to
increase the level of productivity of chemical reactions that rely on them.
Which group of elements makes up more than 90% of the body's mass?
O, C, H
The organic molecules known as phospholipids are key components of cell membranes and composed of what monomeric units?
both glycerol and fatty acids
Which of the following is a way to recognize a carbohydrate by looking at its name only?
It ends in -ose
Which of the following is NOT considered an essential element for a living organism?
mercury
The largest carbohydrate molecules are called polysaccharides because they are composed of ________ molecules bonded together with one another.
sugar
Essential amino acids that are used to build proteins
can be derived from the foods we eat and digest.
Which of the following are examples of cations?
Ca2+
A positively charged ion is called a(n)
cation.
The most important polar molecule is ________ because it is practically a universal solvent
water
A free radical is a
molecule with an unpaired electron.
The chemical bonding behavior of an atom is directly determined by
the number and arrangement of electrons.
Atoms in a covalent molecule
can share electrons in single pairs, double pairs, or triple pairs.
The weak interactions between atoms that keep atoms near each other but don't tightly bind them together are called
hydrogen bonds and van der Waals forces.
All of these statements about carbohydrates are true except one. Identify the exception.
Glycogen is important both for energy storage and to provide structure for cells
In regard to lipids, the term unsaturated refers to
the presence of double bonds between adjacent carbon atoms in a fatty acid.
Each amino acid differs from others in the
chemical structure of the R group.
Nucleic acids are polymers of units called
nucleotides
A nucleotide consists of a
five-carbon sugar, a nitrogenous base, and a phosphate group.
According to the rules of complementary base pairing, a nucleotide containing the base cytosine would only pair with a nucleotide containing the base
guanine.
The most important energy-transferring compound in cells is a nucleotide known as
adenosine triphosphate.
Which bases below are purines?
1. adenine
2. cytosine
3. guanine
4. thymine
5. uracil
1 and 3
Polymers are a typical formation of ________ molecules.
organic
Cholesterol is
a precursor to steroid hormones and a structural component of cell membranes.
A molecule referred to as highly soluble is
very likely to dissolve in water and is called aqueous
Match the correct subatomic particle with the statement about it.
A. proton(s)
B. neutron(s)
C. electron(s)
Isotopes of the same element differ by having different numbers of ________.
neutron(s)
Match the correct subatomic particle with the statement about it.
A. proton(s)
B. neutron(s)
C. electron(s)
The identity of an element can be determined by the number of ________.
proton(s)
Match the correct subatomic particle with the statement about it.
A. proton(s)
B. neutron(s)
C. electron(s)
This particle has a charge of +1 and a mass of 1.
proton(s)
Match the correct subatomic particle with the statement about it.
A. proton(s)
B. neutron(s)
C. electron(s)
This particle has a charge of -1 and a negligible mass.
electron(s)
Match the correct subatomic particle with the statement about it.
A. proton(s)
B. neutron(s)
C. electron(s)
This particle has a neutral charge and a mass of 1.
neutron(s)
Match the symbol with the correct element:
A. P
B. Na
C. Ca
D. C
E. K
F. Pb
calcium
Ca
Match the symbol with the correct element:
A. P
B. Na
C. Ca
D. C
E. K
F. Pb
carbon
C
Match the symbol with the correct element:
A. P
B. Na
C. Ca
D. C
E. K
F. Pb
potassium
K
Match the symbol with the correct element:
A. P
B. Na
C. Ca
D. C
E. K
F. Pb
phosphorus
P
Match the symbol with the correct element:
A. P
B. Na
C. Ca
D. C
E. K
F. Pb
lead
Pb
Identify each of the following as an element (A) or a compound (B).
CO2
compound
Identify each of the following as an element (A) or a compound (B).
C
element
Identify each of the following as an element (A) or a compound (B).
O2
compound
Match each bond type with its description.
A. van der Waals
B. ionic
C. hydrogen
D. covalent
This results when an atom has such a strong attraction for electrons that it pulls one or more electrons completely away from another atom.
ionic
Match each bond type with its description.
A. van der Waals
B. ionic
C. hydrogen
D. covalent
These are weak attractive forces between hydrogen and certain other atoms.
hydrogen
Match each level of protein structure with its description.
A. primary
B. secondary
C. tertiary
D. quaternary
applies to proteins containing more than one peptide chain
quaternary
Match each level of protein structure with its description.
A. primary
B. secondary
C. tertiary
D. quaternary
the sequence and number of amino acids in the chain
primary
Match each level of protein structure with its description.
A. primary
B. secondary
C. tertiary
D. quaternary
the three-dimensional shape of an amino acid chain; can be fibrous or globular
tertiary
Match each level of protein structure with its description.
A. primary
B. secondary
C. tertiary
D. quaternary
the spatial arrangement of amino acids; can be a helix or a pleated sheet
secondary
Match the descriptions to the correct protein category.
A. fibrous
B. globular
soluble in water
globular
Match the descriptions to the correct protein category.
A. fibrous
B. globular
keratin
fibrous
The alpha-helix and pleated sheet are examples of the ________ structure of a protein.
secondary
Interactions between different globular or fibrous polypeptide chains result in which type of structure?
quaternary
The concentration of a solution expresses the amount of
solute per volume of solution
A component of an important buffer in the human body is
HCO3-.
Which of the following substances is most alkaline?
urine, pH = 6
If a substance has a pH that is less than 7, it is considered
acidic.
**You take salt and add it to a beaker containing water. You have just created which of the following?
solution
**What pieces of information do you need to know in order to calculate the molecular weight of a substance?
atomic mass of each element
the number of atoms of each element
anions _ electrons and are _ charged
gain, negatively
MAYBE: Function of protiens (4)
support and structure, catalyst, carrying of messages, transport