What is the term for proteins that carry materials from one place to another in the body??
Transport Proteins
What is the acidic functional group that characterizes amino acids??
Carboxyl Group
What is the term used to describe the molecule formed by condensing only two amino acids??
Dipeptide
In a peptide, what do we call the last amino acid that has a free alpha-carboxylate group??
C-terminal amino acid
What determines the primary structure of a protein??
The information contained in the gene from the proteins, or the DNA nucleotide sequence in the gene
What is meant by the "primary structure" of a protein??
It is the sequence of the amino acid residues which make up the protein
What type of attractive force is responsible for maintaining the secondary structure of a protein??
Hydrogen bonding between carbonyl and amine groups of peptide bonds
In the alpha-helical structure of proteins, what is the minium whole number of amino acid residues needed to complete one full turn of the helix?? What force, and between what atoms, maintains the shape of the helix??
Four; hydrogen bonding between each carboxyl oxygen and the amide nitrogen four amino acid residues away
What are the names of the two most common types of secondary structure found in proteins??
alpha-helices and beta-pleated sheets
What is the term for the type of B-pleated sheet in which both peptides are aligned from amino terminus to carboxyl terminus??
parallel Beta-pleated sheets
Which structural protein is found in bone, tendon and skin??
Collagen
What disease results from a deficiency of vitamin C??
Scurvy
Name 2 of the unusual amino acids found in collagen??
4-hydroxyproline and 5-hydroxylysine
What general type of interactions are responsible for creating and maintaining the globular tertiary structure of proteins??
R group interactions
List the R group interactions responsible for the tertiary structure of a protein??
Hydrogen bonding between polar R groups, van der Waals attractions betwen hydrophobic R groups, disulfide bridges between cysteines, ionic bridges between positively and negatively charged amino acid R groups
What is meant by the "tertiary structure" of a protein??
It is the overall shape of a molecule, including the way that the alpha-helices and beta-pleated sheets fold on themselves.
What is meant by a prosthetic group on a protein??
It refers to a non-protein group to which the protein is bonded in order to create a functional unit.
Give an example of a protein that requires a prosthetic group for its biological function??
hemoglobin, glycoproteins
What level of protein structure involves more than a single peptide aggregated together to form the functional group??
quaternary
What is meant by the "quaternary structure" of a protein?? Give an example of a protein with a quaternary structure??
it refers to the situation where several individual peptides bind with each other to form a functional protein unit, as in hemoglobin.
What is the major protein component of red blood cells?? What protein is the oxygen storage protein of the skeletal muscles??
Hemoglobin, Myoglobin
How many oxygen molecules can one hemoglobin molecule bind??
four
Compare fetal and adult hemoglobin with respect to their affinities for oxygen??
Fetal hemoglobin has a greater affinity for oxygen than does adult hemoglobin.
Compare the inheritance of sickle cell anemia with that of a sickle cell trait??
Individuals who suffer from sickle cell anemia inherited 2 genes for sickle cell hemoglobin, one from each parent. Individuals with sickle cell trait have inherited only one copy of the gene for sickle cell hemoglobin and one for normal hemoglobin.
How do the primary structures of normal hemoglobin and sickle cell hemoglobin differ??
The proteins differ by a d=single amino acid residue. A glutamic acid residues in normal hemoglobin is replaced by a valine residue in sickle cell hemoglobin.
What is the term for the state of a protein when the organized structures of that protein become completely disorganized??
Denatured
List 3 ways in which proteins may become denatured??
Higher temperature, large changes in PH, organic solvents, heavy metals, detergents, mechanical stress
What sorts of changes occur in the structure of a protein molecule when it becomes denatured??
It loses its secondary structure (alpha-helices and beta-pleated sheets) and tertiary structure (folding)
What is the term for the process by which the peptide bonds in proteins are broken by the addition of water??
Hydrolysis
Which of the following pairs of elements are present in proteins but not in most carbohydrates??
Nitrogen and Sulfer
Which of the following kinds of proteins are biochemical catalysts??
enzymes
Which of the following proteins are involved in muscle contractions??
myosin
Which of the following is a nutrient protein??
albumin
What is the minium number of different amino A??
20
What 2 functional groups are found in all amino acids??
amino and carboxyl
Which amino acid has a methyl group as its R group??
analine
Which amino acid has a -CH2CH2CH2CH2NH2 as its R group??
lysine
What level of protein structure specifies the sequence of amino acids in the protein??
primary
What is the most common type of secondary structure in a protein??
alpha-helix
What force of attraction gives the rise to the alpha-helix??
hydrogen bonding
Which of the following amino acids are found in large amounts of collagen??
glycine
Which protein accounts for about a third of the total protein content in the human body??
collagen
What essential type of reaction of collagen requires the presence of vitamin C before it would occur??
hyrdrolysis
What level of protein structure os created by the binding of several peptides to produce a functional protein??
quaternary
What level(s) of protein structure is/are created in part by disulfide bridges??
tertiary
Which of the following ions or molecules stimulates release of oxygen by hemoglobin??
H+
Blood proteins will become denatured when they develop an overall negative charge as a result of..........
an increase in pH
When a protein is denatured, which of the following levels of structure is/are affected??
more than one of the above
Whcih of the following is a source of complete protein??
chicken
Humans do not require amino acids or their component elements for incorporation into.....
glycogen
Proteins are an important nutrient because they provide the elements nitrogen and sulfer, which are not provided by dietary carbohydrates and lipids
true
Condensation of molecules of glycine with one of valine can produce 2 possible dipeptide molecules.
true
Similarities and differences in the primary structures of a protein isolated from 2 different organisms can provide and estimate of the evolutionary relationship between the 2 organisms
true
Hydrogen bonding is responsible for the primary structure of proteins
false
Hydroxyapatite is a polymer of collagen and minerals
false
Glycoproteins are often found as receptors on the surface of cells
true
If the pH of a protein solution becomes very low, the protein molecules will become polyanions
false
Compared to a protein molecule which has no electrical charge, and negatively charged protein will be less soluble in water
false
A fully vegetarian diet cannot provide a complete source of protein
false
Our body cells can synthesize nonessentail amino acids, but not essential ones
true
Protein digestion begins in the small intestine through the action of the enzyme pepsin
false