Nutrition Exam 2 prep

What are the non-protein amino acids?

• Homocysteine

• Ornithine

• Citrulline

• Argininosuccinate

• Carnitine

• Creatine

• Taurine

How are non-protein amino acids formed?

They are intermediates in amino acid metabolism

What is homocysteine an intermediate of?

Methionine to cysteine

What are the urea cycle intermediates?

Ornithine, citruline, arginosuccinate

What is carnitine an intermediate of?

Rate-limiting step in beta-oxidation of FA to generate energy (ATP)

What is the function of carnitine?

Transports fatty acids across mitochondrial membrane

What is creatine used in?

Creatine phosphate shuttle

What is the function of creatine?

• Short, quick bursts of energy in muscle

• May stimulate fast-twitch muscle hypertrophy

• Increased water retention in muscle

What is taurine?

Component of taurocholic acid

What does taurine do for the body?

• Enhances function of the rods/cones in the eye

• Enhances contractile strength of the heart muscle

• Acts as an antioxidant

What is taurine an essential amino acid for?

Cats

What can occur if a cats diet lacks taurine?

Macular degeneration (blindness) and dilated cardiomyopathy

Why do cats need taurine?

It is a dietary essential

Where can taurine be found in a mammal?

It can be found in high concentrations in brain tissue

What role does taurine play in energy drinks?

It has a synergistic effect with caffeine and may decrease anxiety associated with high caffeine dose.

How many levels of protein structure are there?

4

What is the primary structure of protein?

Peptide bond

How many forms of protein secondary structure are there?

2

What are the forms of protein secondary structure?

• alpha helix

• beta pleated sheet

What does alpha helix structure resemble?

Coiled “phone cord”

What does the beta pleated sheet resemble?

Folded “zig-zag” pleats

What is between the amino acids within the protein?

Hydrogen bonding

Can both forms exist within the same protein?

Yes

What are the components of tertiary structure?

Folding/bending of 2 degree structure and binding between R groups

List the R groups in the tertiary structure of a protein.

• OH groups (Ser, Thr, hLys, hPro)

• Cystine (S-S bonds)

• Ionic bonding (+/- charges)

• Hydrophilic/hydrophobic interactions

What is the quaternary structure in proteins?

Interaction of two or more proteins in their tertiary conformation