HUN 2000L EXAM QUESTIONS WITH
CORRECT ANSWERS
Central Dogma of Life - ANSWER-DNA > RNA > Protein
Gene - ANSWER-A stretch of DNA that provides the blueprint for the structure of a
polypeptide chain is called a gene
Where does protein digestion begin? - ANSWER-in the stomach;
Hydrochloric acid denatures proteins, opening up their 3-dimensional structure making
them accessible to enzyme attack
What activates the protein-digesting enzyme, pepsin which breaks protein into
polypeptides and amino acids - ANSWER-Stomach acid
Pancreatic protein-digesting enzymes - ANSWER-trypsin, chymotrypsin, and
carboxypeptidases
When the polypeptides enter the small intestine, they are broken down into smaller
peptides and amino acids by a host of pancreatic protein-digesting enzymes such as
trypsin, chymotrypsin, and carboxypeptidases
How can a protein be quantitatively be assayed? - ANSWER-by spectrophotometric
methods
What are spectrophotometric methods for determining the protein content of a food
based on? - ANSWER-binding of a reagent to either specific amino acids or specific
bonds in the protein
What happens in a Biuret assay? - ANSWER-, absorbance measured by the
spectrophotometer is a function of protein concentration. Under alkaline conditions,
substances containing two or more peptide bonds form a purple complex with the
copper salts in the Biuret reagent producing a colored solution. The more protein in the
sample the more color there is in the solution and the greater the absorbance indicated
by the spectrophotometer.
Magnification - ANSWER-Ratio between apparent size of the object as seen through
the microscope (image size) to the real size of the object (object size)
Image Size - ANSWER-apparent size of the object as seen through the microscope
Object Size - ANSWER-real size of the object
CORRECT ANSWERS
Central Dogma of Life - ANSWER-DNA > RNA > Protein
Gene - ANSWER-A stretch of DNA that provides the blueprint for the structure of a
polypeptide chain is called a gene
Where does protein digestion begin? - ANSWER-in the stomach;
Hydrochloric acid denatures proteins, opening up their 3-dimensional structure making
them accessible to enzyme attack
What activates the protein-digesting enzyme, pepsin which breaks protein into
polypeptides and amino acids - ANSWER-Stomach acid
Pancreatic protein-digesting enzymes - ANSWER-trypsin, chymotrypsin, and
carboxypeptidases
When the polypeptides enter the small intestine, they are broken down into smaller
peptides and amino acids by a host of pancreatic protein-digesting enzymes such as
trypsin, chymotrypsin, and carboxypeptidases
How can a protein be quantitatively be assayed? - ANSWER-by spectrophotometric
methods
What are spectrophotometric methods for determining the protein content of a food
based on? - ANSWER-binding of a reagent to either specific amino acids or specific
bonds in the protein
What happens in a Biuret assay? - ANSWER-, absorbance measured by the
spectrophotometer is a function of protein concentration. Under alkaline conditions,
substances containing two or more peptide bonds form a purple complex with the
copper salts in the Biuret reagent producing a colored solution. The more protein in the
sample the more color there is in the solution and the greater the absorbance indicated
by the spectrophotometer.
Magnification - ANSWER-Ratio between apparent size of the object as seen through
the microscope (image size) to the real size of the object (object size)
Image Size - ANSWER-apparent size of the object as seen through the microscope
Object Size - ANSWER-real size of the object
