Protein Basics
This type of bond links amino acids together
What are peptide bonds?
True or False: Saturated fatty acids have double bonds.
What is False? Saturated fatty acids have no double bonds.
How many calories are in one gram of protein?
What is 4 calories?
What are the two types of complex lipids?
What are phospholipids and glycolipids?
What part of an amino acid structure varies between amino acids?
What is the R group?
Name the 9 essential amino acids.
What are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine?
Which fatty acid isomer is naturally occurring?
What is the cis isomer?
Where are proteins mostly absorbed in the digestive system?
What is the small intestine?
What is the difference between simple and complex lipids?
Simple lipids = fats/oils & waxes. Complex lipids = contain additional groups like phosphate or sugar.
Give an example of an amino acid with an independent function.
What is tryptophan (precursor to serotonin/melatonin)?
What does it mean for a protein to be denatured?
What is the unfolding of a protein’s structure by heat or chemicals, causing loss of function?
What is the structure of a triglyceride?
What is glycerol + 3 fatty acids?
What methods can be used to determine protein content?
What are the Kjeldahl method or equivalents?
Who or what can make odd-chain fatty acids?
What are bacteria?
Define “conditionally essential amino acid.”
An amino acid that is normally nonessential but becomes essential in certain conditions (illness, stress, or rapid growth).
Name two functions of protein in the body.
What is structure, enzyme activity, immune protection, transport, fluid/electrolyte balance, or acid-base balance?
What are the physical traits of fatty acids?
They store energy, build membranes, and act as precursors for other molecules.
How do you calculate crude protein?
Crude Protein = %N × 6.25.
How can fats be protected from oxidation?
By adding antioxidants.
Which amino acid is often considered the “first limiting”?
Lysine (in many diets, especially corn-based).
Explain the difference between rate limiting and first limiting amino acids.
The first limiting amino acid is the essential amino acid in shortest supply relative to need. The rate limiting amino acid is the one that controls protein synthesis rate until its requirement is met.
What is the main concern with trans fatty acids?
They increase risk of cardiovascular disease by raising LDL and lowering HDL cholesterol.
Why are liposomes formed with fatty acids?
To transport fats in aqueous environments.
What makes odd-chain fatty acids unique in plants and animals?
They are uncommon; most plant and animal fatty acids have an even number of carbons.
Compare the structure and function of fibrous vs. globular proteins.
Fibrous proteins (e.g., collagen, keratin) provide structure. Globular proteins (e.g., enzymes, hemoglobin) perform functional/chemical roles.