Lecture March 1

Question 1

Biological systems synthesize and use ___ amino acids

Answer 1

L-amino acids

Question 2

What D-amino acid does the brain synthesize?

Answer 2

D-Serine (Neurotransmitter)

Question 3

Conditionally indispensable amino acids and their precursors

Answer 3

1. Tyrosine from phenylalanine 2. Cysteine from methionine and serine 3. proline from glutamate 4. Arginine from glutamine, glutamate, or aspartate 5. Glutamine from glutamate, ammonia.

Question 4

How long are peptides?

Answer 4

2-50 amino acids

Question 5

How long are proteins

Answer 5

x> than 50 amino acids; 1st amino acid is N terminus last amino acid is C or carboxyl terminus

Question 6

Fibrous proteins

Answer 6

1) polypeptides arranged in long strands or sheets 2) water insoluble (lots of hydrophobic amino acids) 3) Structural ( elastin, collagen, and keratin)

Question 7

Globular proteins

Answer 7

1) polypeptide chains folded into spherical or globular form 2) water soluble 3) diverse functions (enzymes, regulatory proteins)

Question 8

Major protein in eggs

Answer 8

Ovalbumin

Question 9

Major protein in milk

Answer 9

Casein

Question 10

Major proteins in plants

Answer 10

globulins, prolamin, or gluten

Question 11

Major proteins in fish and meat

Answer 11

elatin, collagen, titin, actin, and myosin

Question 12

Are legumes complete of incomplete proteins?

Answer 12

Incomplete proteins. They lack methionine

Question 13

Are wheat, rice, corn,, other grain and grain products complete or incomplete proteins?

Answer 13

Incomplete proteins. Limiting amino acids (Lysine, threonine, and tryptophan)