Proteins and Amino Acids Flashcards

Flashcards about Proteins and Amino Acids based on lecture notes for CHEM 1222 Biochemistry Laboratory.

What are proteins fundamentally composed of?

Proteins are composed of long chains of amino acids linked by peptide bonds.

What determines a protein's primary structure?

The exact sequence of amino acids along the protein chain.

What types of bonds are involve in the formation of the tertiary structure of proteins?

H-bond, hydrophobic interaction, ionic bond, and disulfide bond

Which amino acid is achiral?

Glycine.

At physiological pH, what form do free amino acids largely exist as?

Dipolar ions or zwitterions.

How many amino acids are the building blocks for protein synthesis?

20.

How are hydroxyproline and cystine synthesized?

By modification of proline and cysteine, respectively, after protein biosynthesis.

What vitamin is required for the conversion of proline to hydroxyproline?

Vitamin C (ascorbic acid).

What creates cystine?

Two cysteine molecules connected by a sulfide bond.

What is the function of cystine?

To maintain the tertiary structure of a protein.

What are essential amino acids?

Amino acids that humans cannot synthesize and must obtain from their diet.

Give 5 examples of essential amino acids.

Histidine, Isoleucine, Leucine, Valine, Lysine

What is a peptide bond?

The specific amide bond that links two amino acids together.

What are the products of protein digestion?

Peptides.

What is the range of amino acids in a polypeptide?

More than 10.

What is the range of amino acids in a protein?

300-1000.

What kind of protein is myoglobin?

Globular.

What are the two main types of proteins based on shape?

Globular and Fibrous

In peptides, which groups are involved in forming amide bonds?

Alpha amino and alpha carboxylic acid groups.

What are amino acids incorporated into peptides are called?

Amino acid residues.

How are peptides named?

Using the names of acyl groups ending in ‘yl'.

What are acyl groups?

Amino acids that lack the hydroxyl (-OH) group of the carboxyl.

Describe Biuret Test

Chemical test used for detecting the presence of peptide bonds.

Describe Xanthoproteic Test

Chemical test used to detect the presence of aromatic groups in amino acids.

Describe Millon's Test

A chemical test used for detecting the presence of tyrosine, in proteins and other compounds.

Describe Hopkin's Cole Test

A chemical test used to detect tryptophan in proteins.

Describe Reduced Sulfur Test

A chemical test used for the detection of amino acids containing sulfur like cysteine and cystine.