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Announcements

1. Extra Credit: Playing with Fooda. Flour, salt, water, oil, food colouringb. Milk, sugar, cornstarch, salt, vanilla extract, butter

L15 Amino Acids: Protein Building Blocks

1. General properties and chemistry of the amino acidsa. Chemistry

i. 22 amino acids each containing an alphacarbon, a carboxyl (0COOH orCOO-) group,

an amine (-NH2 orNH3+) group, and an R

Group

1. Glycine &

Cysteine

2. Amino Acidsunder different pHs

3. Isolectric point: Net charge = 0 and solubility is at a minimum

ii. Amino acid Net charge

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1. Below is the structure of the amino acidglutamine (where R=Ch2Ch2CONH2) under

basic hP conditions. What is the net charge of

this amino acid under neutral conditions (i.e.,

hP=7)

a. -1b. 0

c. +1**d. +2

iii. L-amino acid pH

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c. Ionic electrostatic interactionsd. Covalent disulfide bonds

iv. Quarternary (4degree) structure: the interaction oftwo or more proteins to form a new, larger protein

structure

1. Example: Hemoglobin2. Protein-rich foods

a. Sources of protein-rich foods in the dieti. Plant sources

1. Ligumesgreat northern, soybeans22%, 36%2. Nutswalnuts24%3. Cerealswheat, corn, rice p 10, 9, 7%

ii. Animal sources1. MilkCasin, why2.6%, .65%2. CheeseCheddar, American (25, 22%3. EggsWhite4. Meat5. Poultry6. Fish