Proteins

Question 1

What are the four basic categories of amino acids?

Answer 1

• acidic
• basic
• uncharged polar
• non-polar

Question 2

Give two examples of acidic amino acids

Answer 2

• aspartic acid

- glutamic acid

Question 3

Give three examples of basic amino acids

Answer 3

• lysine
• arginine
• histidine

Question 4

Give three examples of uncharged polar amino acids

Answer 4

• aspargine
• glutamine
• serine
• threonine
• tyrosine

Question 5

Give three examples of non polar amino acids

Answer 5

• glycine
• alanine
• valine
• leucine
• isoleucine
• proline
• phenylalanine
• methionine
• tryptophan
• cysteine

Question 6

Give five functions of proteins

Answer 6

• movement
• protection
• transport
• enzymes
• receptors
• structural
• storage
• hormones
• control of gene expression

Question 7

What is the primary structure of proteins?

Answer 7

The sequence of amino acids in a polypeptide chain, this is the source of versatility in protein structure and function

Question 8

What is the secondary structure of proteins?

Answer 8

The spatial arrangement of amino acid residues that are near each other in the linear sequence

• alpha helices - telephone cord shape, held in place by H bonds between N-H group and C=O group of the amino acid in the next turn of the helix
• beta-sheet - pleated structure held together by H bonds between the amide groups of linear polypeptide chains

Question 9

What is the tertiary structure of proteins?

Answer 9

The spatial arrangement of amino acid residues that are far apart in the linear sequence

Question 10

What is the tertiary structure of proteins dependent on?

Answer 10

• Van der Waals
• ionic interactions
• hydrogen bonding
• disulphide bridges
• hydrophobic interaction

Question 11

What is the quaternary structure of proteins?

Answer 11

Refers to the spatial arrangement of individual polypeptide chains in a multi-subunit protein